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postgresql/src/backend/commands/tablecmds.c

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/*-------------------------------------------------------------------------
*
* tablecmds.c
* Commands for creating and altering table structures and settings
*
* Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/backend/commands/tablecmds.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/genam.h"
#include "access/heapam.h"
#include "access/heapam_xlog.h"
#include "access/multixact.h"
#include "access/reloptions.h"
#include "access/relscan.h"
#include "access/sysattr.h"
#include "access/tableam.h"
#include "access/tupconvert.h"
#include "access/xact.h"
#include "access/xlog.h"
#include "catalog/catalog.h"
#include "catalog/dependency.h"
#include "catalog/heap.h"
#include "catalog/index.h"
#include "catalog/indexing.h"
#include "catalog/namespace.h"
#include "catalog/objectaccess.h"
#include "catalog/partition.h"
#include "catalog/pg_am.h"
#include "catalog/pg_collation.h"
#include "catalog/pg_constraint.h"
#include "catalog/pg_depend.h"
#include "catalog/pg_foreign_table.h"
#include "catalog/pg_inherits.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_opclass.h"
#include "catalog/pg_tablespace.h"
#include "catalog/pg_trigger.h"
#include "catalog/pg_type.h"
#include "catalog/storage.h"
#include "catalog/storage_xlog.h"
#include "catalog/toasting.h"
#include "commands/cluster.h"
#include "commands/comment.h"
#include "commands/defrem.h"
#include "commands/event_trigger.h"
#include "commands/policy.h"
#include "commands/sequence.h"
#include "commands/tablecmds.h"
#include "commands/tablespace.h"
#include "commands/trigger.h"
#include "commands/typecmds.h"
#include "commands/user.h"
#include "executor/executor.h"
#include "foreign/foreign.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "nodes/parsenodes.h"
#include "optimizer/optimizer.h"
#include "parser/parse_clause.h"
#include "parser/parse_coerce.h"
#include "parser/parse_collate.h"
#include "parser/parse_expr.h"
#include "parser/parse_oper.h"
#include "parser/parse_relation.h"
#include "parser/parse_type.h"
#include "parser/parse_utilcmd.h"
#include "parser/parser.h"
#include "partitioning/partbounds.h"
#include "partitioning/partdesc.h"
#include "pgstat.h"
#include "rewrite/rewriteDefine.h"
#include "rewrite/rewriteHandler.h"
#include "rewrite/rewriteManip.h"
#include "storage/bufmgr.h"
#include "storage/lmgr.h"
#include "storage/lock.h"
#include "storage/predicate.h"
#include "storage/smgr.h"
#include "utils/acl.h"
#include "utils/builtins.h"
#include "utils/fmgroids.h"
#include "utils/inval.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/partcache.h"
#include "utils/relcache.h"
#include "utils/ruleutils.h"
#include "utils/snapmgr.h"
#include "utils/syscache.h"
#include "utils/timestamp.h"
#include "utils/typcache.h"
/*
* ON COMMIT action list
*/
typedef struct OnCommitItem
{
Oid relid; /* relid of relation */
OnCommitAction oncommit; /* what to do at end of xact */
/*
* If this entry was created during the current transaction,
* creating_subid is the ID of the creating subxact; if created in a prior
* transaction, creating_subid is zero. If deleted during the current
* transaction, deleting_subid is the ID of the deleting subxact; if no
* deletion request is pending, deleting_subid is zero.
*/
SubTransactionId creating_subid;
SubTransactionId deleting_subid;
} OnCommitItem;
static List *on_commits = NIL;
/*
* State information for ALTER TABLE
*
* The pending-work queue for an ALTER TABLE is a List of AlteredTableInfo
* structs, one for each table modified by the operation (the named table
* plus any child tables that are affected). We save lists of subcommands
* to apply to this table (possibly modified by parse transformation steps);
* these lists will be executed in Phase 2. If a Phase 3 step is needed,
* necessary information is stored in the constraints and newvals lists.
*
* Phase 2 is divided into multiple passes; subcommands are executed in
* a pass determined by subcommand type.
*/
#define AT_PASS_UNSET -1 /* UNSET will cause ERROR */
#define AT_PASS_DROP 0 /* DROP (all flavors) */
#define AT_PASS_ALTER_TYPE 1 /* ALTER COLUMN TYPE */
#define AT_PASS_OLD_INDEX 2 /* re-add existing indexes */
#define AT_PASS_OLD_CONSTR 3 /* re-add existing constraints */
/* We could support a RENAME COLUMN pass here, but not currently used */
#define AT_PASS_ADD_COL 4 /* ADD COLUMN */
#define AT_PASS_COL_ATTRS 5 /* set other column attributes */
#define AT_PASS_ADD_INDEX 6 /* ADD indexes */
#define AT_PASS_ADD_CONSTR 7 /* ADD constraints, defaults */
#define AT_PASS_MISC 8 /* other stuff */
#define AT_NUM_PASSES 9
typedef struct AlteredTableInfo
{
/* Information saved before any work commences: */
Oid relid; /* Relation to work on */
char relkind; /* Its relkind */
TupleDesc oldDesc; /* Pre-modification tuple descriptor */
/* Information saved by Phase 1 for Phase 2: */
List *subcmds[AT_NUM_PASSES]; /* Lists of AlterTableCmd */
/* Information saved by Phases 1/2 for Phase 3: */
List *constraints; /* List of NewConstraint */
List *newvals; /* List of NewColumnValue */
bool verify_new_notnull; /* T if we should recheck NOT NULL */
int rewrite; /* Reason for forced rewrite, if any */
Oid newTableSpace; /* new tablespace; 0 means no change */
bool chgPersistence; /* T if SET LOGGED/UNLOGGED is used */
char newrelpersistence; /* if above is true */
Expr *partition_constraint; /* for attach partition validation */
/* true, if validating default due to some other attach/detach */
bool validate_default;
/* Objects to rebuild after completing ALTER TYPE operations */
List *changedConstraintOids; /* OIDs of constraints to rebuild */
List *changedConstraintDefs; /* string definitions of same */
List *changedIndexOids; /* OIDs of indexes to rebuild */
List *changedIndexDefs; /* string definitions of same */
} AlteredTableInfo;
/* Struct describing one new constraint to check in Phase 3 scan */
/* Note: new NOT NULL constraints are handled elsewhere */
typedef struct NewConstraint
{
char *name; /* Constraint name, or NULL if none */
ConstrType contype; /* CHECK or FOREIGN */
Oid refrelid; /* PK rel, if FOREIGN */
Oid refindid; /* OID of PK's index, if FOREIGN */
Oid conid; /* OID of pg_constraint entry, if FOREIGN */
Node *qual; /* Check expr or CONSTR_FOREIGN Constraint */
ExprState *qualstate; /* Execution state for CHECK expr */
} NewConstraint;
/*
* Struct describing one new column value that needs to be computed during
* Phase 3 copy (this could be either a new column with a non-null default, or
* a column that we're changing the type of). Columns without such an entry
* are just copied from the old table during ATRewriteTable. Note that the
* expr is an expression over *old* table values.
*/
typedef struct NewColumnValue
{
AttrNumber attnum; /* which column */
Expr *expr; /* expression to compute */
ExprState *exprstate; /* execution state */
} NewColumnValue;
/*
* Error-reporting support for RemoveRelations
*/
struct dropmsgstrings
{
char kind;
int nonexistent_code;
const char *nonexistent_msg;
const char *skipping_msg;
const char *nota_msg;
const char *drophint_msg;
};
static const struct dropmsgstrings dropmsgstringarray[] = {
{RELKIND_RELATION,
ERRCODE_UNDEFINED_TABLE,
gettext_noop("table \"%s\" does not exist"),
gettext_noop("table \"%s\" does not exist, skipping"),
gettext_noop("\"%s\" is not a table"),
gettext_noop("Use DROP TABLE to remove a table.")},
{RELKIND_SEQUENCE,
ERRCODE_UNDEFINED_TABLE,
gettext_noop("sequence \"%s\" does not exist"),
gettext_noop("sequence \"%s\" does not exist, skipping"),
gettext_noop("\"%s\" is not a sequence"),
gettext_noop("Use DROP SEQUENCE to remove a sequence.")},
{RELKIND_VIEW,
ERRCODE_UNDEFINED_TABLE,
gettext_noop("view \"%s\" does not exist"),
gettext_noop("view \"%s\" does not exist, skipping"),
gettext_noop("\"%s\" is not a view"),
gettext_noop("Use DROP VIEW to remove a view.")},
{RELKIND_MATVIEW,
ERRCODE_UNDEFINED_TABLE,
gettext_noop("materialized view \"%s\" does not exist"),
gettext_noop("materialized view \"%s\" does not exist, skipping"),
gettext_noop("\"%s\" is not a materialized view"),
gettext_noop("Use DROP MATERIALIZED VIEW to remove a materialized view.")},
{RELKIND_INDEX,
ERRCODE_UNDEFINED_OBJECT,
gettext_noop("index \"%s\" does not exist"),
gettext_noop("index \"%s\" does not exist, skipping"),
gettext_noop("\"%s\" is not an index"),
gettext_noop("Use DROP INDEX to remove an index.")},
{RELKIND_COMPOSITE_TYPE,
ERRCODE_UNDEFINED_OBJECT,
gettext_noop("type \"%s\" does not exist"),
gettext_noop("type \"%s\" does not exist, skipping"),
gettext_noop("\"%s\" is not a type"),
gettext_noop("Use DROP TYPE to remove a type.")},
{RELKIND_FOREIGN_TABLE,
ERRCODE_UNDEFINED_OBJECT,
gettext_noop("foreign table \"%s\" does not exist"),
gettext_noop("foreign table \"%s\" does not exist, skipping"),
gettext_noop("\"%s\" is not a foreign table"),
gettext_noop("Use DROP FOREIGN TABLE to remove a foreign table.")},
{RELKIND_PARTITIONED_TABLE,
ERRCODE_UNDEFINED_TABLE,
gettext_noop("table \"%s\" does not exist"),
gettext_noop("table \"%s\" does not exist, skipping"),
gettext_noop("\"%s\" is not a table"),
gettext_noop("Use DROP TABLE to remove a table.")},
{RELKIND_PARTITIONED_INDEX,
ERRCODE_UNDEFINED_OBJECT,
gettext_noop("index \"%s\" does not exist"),
gettext_noop("index \"%s\" does not exist, skipping"),
gettext_noop("\"%s\" is not an index"),
gettext_noop("Use DROP INDEX to remove an index.")},
{'\0', 0, NULL, NULL, NULL, NULL}
};
struct DropRelationCallbackState
{
char relkind;
Oid heapOid;
Oid partParentOid;
bool concurrent;
};
/* Alter table target-type flags for ATSimplePermissions */
#define ATT_TABLE 0x0001
#define ATT_VIEW 0x0002
#define ATT_MATVIEW 0x0004
#define ATT_INDEX 0x0008
#define ATT_COMPOSITE_TYPE 0x0010
#define ATT_FOREIGN_TABLE 0x0020
#define ATT_PARTITIONED_INDEX 0x0040
/*
* Partition tables are expected to be dropped when the parent partitioned
* table gets dropped. Hence for partitioning we use AUTO dependency.
* Otherwise, for regular inheritance use NORMAL dependency.
*/
#define child_dependency_type(child_is_partition) \
((child_is_partition) ? DEPENDENCY_AUTO : DEPENDENCY_NORMAL)
static void truncate_check_rel(Oid relid, Form_pg_class reltuple);
static void truncate_check_activity(Relation rel);
static void RangeVarCallbackForTruncate(const RangeVar *relation,
Oid relId, Oid oldRelId, void *arg);
static List *MergeAttributes(List *schema, List *supers, char relpersistence,
bool is_partition, List **supconstr);
static bool MergeCheckConstraint(List *constraints, char *name, Node *expr);
static void MergeAttributesIntoExisting(Relation child_rel, Relation parent_rel);
static void MergeConstraintsIntoExisting(Relation child_rel, Relation parent_rel);
static void StoreCatalogInheritance(Oid relationId, List *supers,
bool child_is_partition);
static void StoreCatalogInheritance1(Oid relationId, Oid parentOid,
int32 seqNumber, Relation inhRelation,
bool child_is_partition);
static int findAttrByName(const char *attributeName, List *schema);
static void AlterIndexNamespaces(Relation classRel, Relation rel,
Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved);
static void AlterSeqNamespaces(Relation classRel, Relation rel,
Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved,
LOCKMODE lockmode);
static ObjectAddress ATExecAlterConstraint(Relation rel, AlterTableCmd *cmd,
bool recurse, bool recursing, LOCKMODE lockmode);
static ObjectAddress ATExecValidateConstraint(Relation rel, char *constrName,
bool recurse, bool recursing, LOCKMODE lockmode);
static int transformColumnNameList(Oid relId, List *colList,
int16 *attnums, Oid *atttypids);
static int transformFkeyGetPrimaryKey(Relation pkrel, Oid *indexOid,
List **attnamelist,
int16 *attnums, Oid *atttypids,
Oid *opclasses);
static Oid transformFkeyCheckAttrs(Relation pkrel,
int numattrs, int16 *attnums,
Oid *opclasses);
static void checkFkeyPermissions(Relation rel, int16 *attnums, int natts);
static CoercionPathType findFkeyCast(Oid targetTypeId, Oid sourceTypeId,
Oid *funcid);
static void validateCheckConstraint(Relation rel, HeapTuple constrtup);
static void validateForeignKeyConstraint(char *conname,
Relation rel, Relation pkrel,
Oid pkindOid, Oid constraintOid);
static void ATController(AlterTableStmt *parsetree,
Relation rel, List *cmds, bool recurse, LOCKMODE lockmode);
static void ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd,
bool recurse, bool recursing, LOCKMODE lockmode);
static void ATRewriteCatalogs(List **wqueue, LOCKMODE lockmode);
static void ATExecCmd(List **wqueue, AlteredTableInfo *tab, Relation rel,
AlterTableCmd *cmd, LOCKMODE lockmode);
static void ATRewriteTables(AlterTableStmt *parsetree,
List **wqueue, LOCKMODE lockmode);
static void ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode);
static AlteredTableInfo *ATGetQueueEntry(List **wqueue, Relation rel);
static void ATSimplePermissions(Relation rel, int allowed_targets);
static void ATWrongRelkindError(Relation rel, int allowed_targets);
static void ATSimpleRecursion(List **wqueue, Relation rel,
AlterTableCmd *cmd, bool recurse, LOCKMODE lockmode);
static void ATCheckPartitionsNotInUse(Relation rel, LOCKMODE lockmode);
static void ATTypedTableRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd,
LOCKMODE lockmode);
static List *find_typed_table_dependencies(Oid typeOid, const char *typeName,
DropBehavior behavior);
static void ATPrepAddColumn(List **wqueue, Relation rel, bool recurse, bool recursing,
bool is_view, AlterTableCmd *cmd, LOCKMODE lockmode);
static ObjectAddress ATExecAddColumn(List **wqueue, AlteredTableInfo *tab,
Relation rel, ColumnDef *colDef,
bool recurse, bool recursing,
bool if_not_exists, LOCKMODE lockmode);
static bool check_for_column_name_collision(Relation rel, const char *colname,
bool if_not_exists);
static void add_column_datatype_dependency(Oid relid, int32 attnum, Oid typid);
static void add_column_collation_dependency(Oid relid, int32 attnum, Oid collid);
static void ATPrepDropNotNull(Relation rel, bool recurse, bool recursing);
static ObjectAddress ATExecDropNotNull(Relation rel, const char *colName, LOCKMODE lockmode);
static void ATPrepSetNotNull(List **wqueue, Relation rel,
AlterTableCmd *cmd, bool recurse, bool recursing,
LOCKMODE lockmode);
static ObjectAddress ATExecSetNotNull(AlteredTableInfo *tab, Relation rel,
const char *colName, LOCKMODE lockmode);
static void ATExecCheckNotNull(AlteredTableInfo *tab, Relation rel,
const char *colName, LOCKMODE lockmode);
static bool NotNullImpliedByRelConstraints(Relation rel, Form_pg_attribute attr);
static bool ConstraintImpliedByRelConstraint(Relation scanrel,
List *testConstraint, List *provenConstraint);
static ObjectAddress ATExecColumnDefault(Relation rel, const char *colName,
Node *newDefault, LOCKMODE lockmode);
static ObjectAddress ATExecAddIdentity(Relation rel, const char *colName,
Node *def, LOCKMODE lockmode);
static ObjectAddress ATExecSetIdentity(Relation rel, const char *colName,
Node *def, LOCKMODE lockmode);
static ObjectAddress ATExecDropIdentity(Relation rel, const char *colName, bool missing_ok, LOCKMODE lockmode);
static void ATPrepSetStatistics(Relation rel, const char *colName, int16 colNum,
Node *newValue, LOCKMODE lockmode);
static ObjectAddress ATExecSetStatistics(Relation rel, const char *colName, int16 colNum,
Node *newValue, LOCKMODE lockmode);
static ObjectAddress ATExecSetOptions(Relation rel, const char *colName,
Node *options, bool isReset, LOCKMODE lockmode);
static ObjectAddress ATExecSetStorage(Relation rel, const char *colName,
Node *newValue, LOCKMODE lockmode);
static void ATPrepDropColumn(List **wqueue, Relation rel, bool recurse, bool recursing,
AlterTableCmd *cmd, LOCKMODE lockmode);
static ObjectAddress ATExecDropColumn(List **wqueue, Relation rel, const char *colName,
DropBehavior behavior,
bool recurse, bool recursing,
bool missing_ok, LOCKMODE lockmode,
ObjectAddresses *addrs);
static ObjectAddress ATExecAddIndex(AlteredTableInfo *tab, Relation rel,
IndexStmt *stmt, bool is_rebuild, LOCKMODE lockmode);
static ObjectAddress ATExecAddConstraint(List **wqueue,
AlteredTableInfo *tab, Relation rel,
Constraint *newConstraint, bool recurse, bool is_readd,
LOCKMODE lockmode);
static char *ChooseForeignKeyConstraintNameAddition(List *colnames);
static ObjectAddress ATExecAddIndexConstraint(AlteredTableInfo *tab, Relation rel,
IndexStmt *stmt, LOCKMODE lockmode);
static ObjectAddress ATAddCheckConstraint(List **wqueue,
AlteredTableInfo *tab, Relation rel,
Constraint *constr,
bool recurse, bool recursing, bool is_readd,
LOCKMODE lockmode);
static ObjectAddress ATAddForeignKeyConstraint(List **wqueue, AlteredTableInfo *tab,
Relation rel, Constraint *fkconstraint, Oid parentConstr,
bool recurse, bool recursing,
LOCKMODE lockmode);
static ObjectAddress addFkRecurseReferenced(List **wqueue, Constraint *fkconstraint,
Relation rel, Relation pkrel, Oid indexOid, Oid parentConstr,
int numfks, int16 *pkattnum, int16 *fkattnum,
Oid *pfeqoperators, Oid *ppeqoperators, Oid *ffeqoperators,
bool old_check_ok);
static void addFkRecurseReferencing(List **wqueue, Constraint *fkconstraint,
Relation rel, Relation pkrel, Oid indexOid, Oid parentConstr,
int numfks, int16 *pkattnum, int16 *fkattnum,
Oid *pfeqoperators, Oid *ppeqoperators, Oid *ffeqoperators,
bool old_check_ok, LOCKMODE lockmode);
static void CloneForeignKeyConstraints(List **wqueue, Relation parentRel,
Relation partitionRel);
static void CloneFkReferenced(Relation parentRel, Relation partitionRel);
static void CloneFkReferencing(List **wqueue, Relation parentRel,
Relation partRel);
static void createForeignKeyCheckTriggers(Oid myRelOid, Oid refRelOid,
Constraint *fkconstraint, Oid constraintOid,
Oid indexOid);
static void createForeignKeyActionTriggers(Relation rel, Oid refRelOid,
Constraint *fkconstraint, Oid constraintOid,
Oid indexOid);
static bool tryAttachPartitionForeignKey(ForeignKeyCacheInfo *fk,
Oid partRelid,
Oid parentConstrOid, int numfks,
AttrNumber *mapped_conkey, AttrNumber *confkey,
Oid *conpfeqop);
static void ATExecDropConstraint(Relation rel, const char *constrName,
DropBehavior behavior,
bool recurse, bool recursing,
bool missing_ok, LOCKMODE lockmode);
static void ATPrepAlterColumnType(List **wqueue,
AlteredTableInfo *tab, Relation rel,
bool recurse, bool recursing,
AlterTableCmd *cmd, LOCKMODE lockmode);
static bool ATColumnChangeRequiresRewrite(Node *expr, AttrNumber varattno);
static ObjectAddress ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
AlterTableCmd *cmd, LOCKMODE lockmode);
static void RememberConstraintForRebuilding(Oid conoid, AlteredTableInfo *tab);
static void RememberIndexForRebuilding(Oid indoid, AlteredTableInfo *tab);
static void ATPostAlterTypeCleanup(List **wqueue, AlteredTableInfo *tab,
LOCKMODE lockmode);
static void ATPostAlterTypeParse(Oid oldId, Oid oldRelId, Oid refRelId,
char *cmd, List **wqueue, LOCKMODE lockmode,
bool rewrite);
static void RebuildConstraintComment(AlteredTableInfo *tab, int pass,
Oid objid, Relation rel, List *domname,
const char *conname);
static void TryReuseIndex(Oid oldId, IndexStmt *stmt);
static void TryReuseForeignKey(Oid oldId, Constraint *con);
static ObjectAddress ATExecAlterColumnGenericOptions(Relation rel, const char *colName,
List *options, LOCKMODE lockmode);
static void change_owner_fix_column_acls(Oid relationOid,
Oid oldOwnerId, Oid newOwnerId);
static void change_owner_recurse_to_sequences(Oid relationOid,
Oid newOwnerId, LOCKMODE lockmode);
static ObjectAddress ATExecClusterOn(Relation rel, const char *indexName,
LOCKMODE lockmode);
static void ATExecDropCluster(Relation rel, LOCKMODE lockmode);
static bool ATPrepChangePersistence(Relation rel, bool toLogged);
static void ATPrepSetTableSpace(AlteredTableInfo *tab, Relation rel,
const char *tablespacename, LOCKMODE lockmode);
static void ATExecSetTableSpace(Oid tableOid, Oid newTableSpace, LOCKMODE lockmode);
static void ATExecSetTableSpaceNoStorage(Relation rel, Oid newTableSpace);
static void ATExecSetRelOptions(Relation rel, List *defList,
AlterTableType operation,
LOCKMODE lockmode);
static void ATExecEnableDisableTrigger(Relation rel, const char *trigname,
char fires_when, bool skip_system, LOCKMODE lockmode);
static void ATExecEnableDisableRule(Relation rel, const char *rulename,
char fires_when, LOCKMODE lockmode);
static void ATPrepAddInherit(Relation child_rel);
static ObjectAddress ATExecAddInherit(Relation child_rel, RangeVar *parent, LOCKMODE lockmode);
static ObjectAddress ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode);
static void drop_parent_dependency(Oid relid, Oid refclassid, Oid refobjid,
DependencyType deptype);
static ObjectAddress ATExecAddOf(Relation rel, const TypeName *ofTypename, LOCKMODE lockmode);
static void ATExecDropOf(Relation rel, LOCKMODE lockmode);
static void ATExecReplicaIdentity(Relation rel, ReplicaIdentityStmt *stmt, LOCKMODE lockmode);
static void ATExecGenericOptions(Relation rel, List *options);
static void ATExecEnableRowSecurity(Relation rel);
static void ATExecDisableRowSecurity(Relation rel);
static void ATExecForceNoForceRowSecurity(Relation rel, bool force_rls);
static void index_copy_data(Relation rel, RelFileNode newrnode);
static const char *storage_name(char c);
static void RangeVarCallbackForDropRelation(const RangeVar *rel, Oid relOid,
Oid oldRelOid, void *arg);
static void RangeVarCallbackForAlterRelation(const RangeVar *rv, Oid relid,
Oid oldrelid, void *arg);
static PartitionSpec *transformPartitionSpec(Relation rel, PartitionSpec *partspec, char *strategy);
static void ComputePartitionAttrs(ParseState *pstate, Relation rel, List *partParams, AttrNumber *partattrs,
List **partexprs, Oid *partopclass, Oid *partcollation, char strategy);
static void CreateInheritance(Relation child_rel, Relation parent_rel);
static void RemoveInheritance(Relation child_rel, Relation parent_rel);
static ObjectAddress ATExecAttachPartition(List **wqueue, Relation rel,
PartitionCmd *cmd);
static void AttachPartitionEnsureIndexes(Relation rel, Relation attachrel);
static void QueuePartitionConstraintValidation(List **wqueue, Relation scanrel,
List *partConstraint,
bool validate_default);
static void CloneRowTriggersToPartition(Relation parent, Relation partition);
static ObjectAddress ATExecDetachPartition(Relation rel, RangeVar *name);
static ObjectAddress ATExecAttachPartitionIdx(List **wqueue, Relation rel,
RangeVar *name);
static void validatePartitionedIndex(Relation partedIdx, Relation partedTbl);
static void refuseDupeIndexAttach(Relation parentIdx, Relation partIdx,
Relation partitionTbl);
static List *GetParentedForeignKeyRefs(Relation partition);
static void ATDetachCheckNoForeignKeyRefs(Relation partition);
/* ----------------------------------------------------------------
* DefineRelation
* Creates a new relation.
*
* stmt carries parsetree information from an ordinary CREATE TABLE statement.
* The other arguments are used to extend the behavior for other cases:
* relkind: relkind to assign to the new relation
* ownerId: if not InvalidOid, use this as the new relation's owner.
* typaddress: if not null, it's set to the pg_type entry's address.
* queryString: for error reporting
*
* Note that permissions checks are done against current user regardless of
* ownerId. A nonzero ownerId is used when someone is creating a relation
* "on behalf of" someone else, so we still want to see that the current user
* has permissions to do it.
*
* If successful, returns the address of the new relation.
* ----------------------------------------------------------------
*/
ObjectAddress
DefineRelation(CreateStmt *stmt, char relkind, Oid ownerId,
ObjectAddress *typaddress, const char *queryString)
{
char relname[NAMEDATALEN];
Oid namespaceId;
Oid relationId;
Oid tablespaceId;
Relation rel;
TupleDesc descriptor;
List *inheritOids;
List *old_constraints;
List *rawDefaults;
List *cookedDefaults;
Datum reloptions;
ListCell *listptr;
AttrNumber attnum;
bool partitioned;
static char *validnsps[] = HEAP_RELOPT_NAMESPACES;
Oid ofTypeId;
ObjectAddress address;
LOCKMODE parentLockmode;
const char *accessMethod = NULL;
Oid accessMethodId = InvalidOid;
/*
* Truncate relname to appropriate length (probably a waste of time, as
* parser should have done this already).
*/
StrNCpy(relname, stmt->relation->relname, NAMEDATALEN);
/*
* Check consistency of arguments
*/
if (stmt->oncommit != ONCOMMIT_NOOP
&& stmt->relation->relpersistence != RELPERSISTENCE_TEMP)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("ON COMMIT can only be used on temporary tables")));
if (stmt->partspec != NULL)
{
if (relkind != RELKIND_RELATION)
elog(ERROR, "unexpected relkind: %d", (int) relkind);
relkind = RELKIND_PARTITIONED_TABLE;
partitioned = true;
}
else
partitioned = false;
/*
* Look up the namespace in which we are supposed to create the relation,
* check we have permission to create there, lock it against concurrent
* drop, and mark stmt->relation as RELPERSISTENCE_TEMP if a temporary
* namespace is selected.
*/
namespaceId =
RangeVarGetAndCheckCreationNamespace(stmt->relation, NoLock, NULL);
/*
* Security check: disallow creating temp tables from security-restricted
* code. This is needed because calling code might not expect untrusted
* tables to appear in pg_temp at the front of its search path.
*/
if (stmt->relation->relpersistence == RELPERSISTENCE_TEMP
&& InSecurityRestrictedOperation())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("cannot create temporary table within security-restricted operation")));
/*
* Determine the lockmode to use when scanning parents. A self-exclusive
* lock is needed here.
*
* For regular inheritance, if two backends attempt to add children to the
* same parent simultaneously, and that parent has no pre-existing
* children, then both will attempt to update the parent's relhassubclass
* field, leading to a "tuple concurrently updated" error. Also, this
* interlocks against a concurrent ANALYZE on the parent table, which
* might otherwise be attempting to clear the parent's relhassubclass
* field, if its previous children were recently dropped.
*
* If the child table is a partition, then we instead grab an exclusive
* lock on the parent because its partition descriptor will be changed by
* addition of the new partition.
*/
parentLockmode = (stmt->partbound != NULL ? AccessExclusiveLock :
ShareUpdateExclusiveLock);
/* Determine the list of OIDs of the parents. */
inheritOids = NIL;
foreach(listptr, stmt->inhRelations)
{
RangeVar *rv = (RangeVar *) lfirst(listptr);
Oid parentOid;
parentOid = RangeVarGetRelid(rv, parentLockmode, false);
/*
* Reject duplications in the list of parents.
*/
if (list_member_oid(inheritOids, parentOid))
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_TABLE),
errmsg("relation \"%s\" would be inherited from more than once",
get_rel_name(parentOid))));
inheritOids = lappend_oid(inheritOids, parentOid);
}
/*
* Select tablespace to use: an explicitly indicated one, or (in the case
* of a partitioned table) the parent's, if it has one.
*/
if (stmt->tablespacename)
{
tablespaceId = get_tablespace_oid(stmt->tablespacename, false);
if (partitioned && tablespaceId == MyDatabaseTableSpace)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot specify default tablespace for partitioned relations")));
}
else if (stmt->partbound)
{
/*
* For partitions, when no other tablespace is specified, we default
* the tablespace to the parent partitioned table's.
*/
Assert(list_length(inheritOids) == 1);
tablespaceId = get_rel_tablespace(linitial_oid(inheritOids));
}
else
tablespaceId = InvalidOid;
/* still nothing? use the default */
if (!OidIsValid(tablespaceId))
tablespaceId = GetDefaultTablespace(stmt->relation->relpersistence,
partitioned);
/* Check permissions except when using database's default */
if (OidIsValid(tablespaceId) && tablespaceId != MyDatabaseTableSpace)
{
AclResult aclresult;
aclresult = pg_tablespace_aclcheck(tablespaceId, GetUserId(),
ACL_CREATE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, OBJECT_TABLESPACE,
get_tablespace_name(tablespaceId));
}
/* In all cases disallow placing user relations in pg_global */
if (tablespaceId == GLOBALTABLESPACE_OID)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("only shared relations can be placed in pg_global tablespace")));
/* Identify user ID that will own the table */
if (!OidIsValid(ownerId))
ownerId = GetUserId();
/*
* Parse and validate reloptions, if any.
*/
reloptions = transformRelOptions((Datum) 0, stmt->options, NULL, validnsps,
true, false);
if (relkind == RELKIND_VIEW)
(void) view_reloptions(reloptions, true);
else
(void) heap_reloptions(relkind, reloptions, true);
if (stmt->ofTypename)
{
AclResult aclresult;
ofTypeId = typenameTypeId(NULL, stmt->ofTypename);
aclresult = pg_type_aclcheck(ofTypeId, GetUserId(), ACL_USAGE);
if (aclresult != ACLCHECK_OK)
aclcheck_error_type(aclresult, ofTypeId);
}
else
ofTypeId = InvalidOid;
/*
* Look up inheritance ancestors and generate relation schema, including
* inherited attributes. (Note that stmt->tableElts is destructively
* modified by MergeAttributes.)
*/
stmt->tableElts =
MergeAttributes(stmt->tableElts, inheritOids,
stmt->relation->relpersistence,
stmt->partbound != NULL,
&old_constraints);
/*
* Create a tuple descriptor from the relation schema. Note that this
* deals with column names, types, and NOT NULL constraints, but not
* default values or CHECK constraints; we handle those below.
*/
descriptor = BuildDescForRelation(stmt->tableElts);
/*
* Find columns with default values and prepare for insertion of the
* defaults. Pre-cooked (that is, inherited) defaults go into a list of
* CookedConstraint structs that we'll pass to heap_create_with_catalog,
* while raw defaults go into a list of RawColumnDefault structs that will
* be processed by AddRelationNewConstraints. (We can't deal with raw
* expressions until we can do transformExpr.)
*
* We can set the atthasdef flags now in the tuple descriptor; this just
* saves StoreAttrDefault from having to do an immediate update of the
* pg_attribute rows.
*/
rawDefaults = NIL;
cookedDefaults = NIL;
attnum = 0;
foreach(listptr, stmt->tableElts)
{
ColumnDef *colDef = lfirst(listptr);
Form_pg_attribute attr;
attnum++;
attr = TupleDescAttr(descriptor, attnum - 1);
if (colDef->raw_default != NULL)
{
RawColumnDefault *rawEnt;
Assert(colDef->cooked_default == NULL);
rawEnt = (RawColumnDefault *) palloc(sizeof(RawColumnDefault));
rawEnt->attnum = attnum;
rawEnt->raw_default = colDef->raw_default;
rawEnt->missingMode = false;
rawEnt->generated = colDef->generated;
rawDefaults = lappend(rawDefaults, rawEnt);
attr->atthasdef = true;
}
else if (colDef->cooked_default != NULL)
{
CookedConstraint *cooked;
cooked = (CookedConstraint *) palloc(sizeof(CookedConstraint));
cooked->contype = CONSTR_DEFAULT;
cooked->conoid = InvalidOid; /* until created */
cooked->name = NULL;
cooked->attnum = attnum;
cooked->expr = colDef->cooked_default;
cooked->skip_validation = false;
cooked->is_local = true; /* not used for defaults */
cooked->inhcount = 0; /* ditto */
cooked->is_no_inherit = false;
cookedDefaults = lappend(cookedDefaults, cooked);
attr->atthasdef = true;
}
if (colDef->identity)
attr->attidentity = colDef->identity;
if (colDef->generated)
attr->attgenerated = colDef->generated;
}
/*
* If the statement hasn't specified an access method, but we're defining
* a type of relation that needs one, use the default.
*/
if (stmt->accessMethod != NULL)
{
accessMethod = stmt->accessMethod;
if (partitioned)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("specifying a table access method is not supported on a partitioned table")));
}
else if (relkind == RELKIND_RELATION ||
relkind == RELKIND_TOASTVALUE ||
relkind == RELKIND_MATVIEW)
accessMethod = default_table_access_method;
/* look up the access method, verify it is for a table */
if (accessMethod != NULL)
accessMethodId = get_table_am_oid(accessMethod, false);
/*
* Create the relation. Inherited defaults and constraints are passed in
* for immediate handling --- since they don't need parsing, they can be
* stored immediately.
*/
relationId = heap_create_with_catalog(relname,
namespaceId,
tablespaceId,
InvalidOid,
InvalidOid,
ofTypeId,
ownerId,
accessMethodId,
descriptor,
list_concat(cookedDefaults,
old_constraints),
relkind,
stmt->relation->relpersistence,
false,
false,
stmt->oncommit,
reloptions,
true,
allowSystemTableMods,
false,
InvalidOid,
typaddress);
/*
* We must bump the command counter to make the newly-created relation
* tuple visible for opening.
*/
CommandCounterIncrement();
/*
* Open the new relation and acquire exclusive lock on it. This isn't
* really necessary for locking out other backends (since they can't see
* the new rel anyway until we commit), but it keeps the lock manager from
* complaining about deadlock risks.
*/
rel = relation_open(relationId, AccessExclusiveLock);
/*
* Now add any newly specified column default and generation expressions
* to the new relation. These are passed to us in the form of raw
* parsetrees; we need to transform them to executable expression trees
* before they can be added. The most convenient way to do that is to
* apply the parser's transformExpr routine, but transformExpr doesn't
* work unless we have a pre-existing relation. So, the transformation has
* to be postponed to this final step of CREATE TABLE.
*
* This needs to be before processing the partitioning clauses because
* those could refer to generated columns.
*/
if (rawDefaults)
AddRelationNewConstraints(rel, rawDefaults, NIL,
true, true, false, queryString);
/*
* Make column generation expressions visible for use by partitioning.
*/
CommandCounterIncrement();
/* Process and store partition bound, if any. */
if (stmt->partbound)
{
PartitionBoundSpec *bound;
ParseState *pstate;
Oid parentId = linitial_oid(inheritOids),
defaultPartOid;
Relation parent,
defaultRel = NULL;
RangeTblEntry *rte;
/* Already have strong enough lock on the parent */
parent = table_open(parentId, NoLock);
/*
* We are going to try to validate the partition bound specification
* against the partition key of parentRel, so it better have one.
*/
if (parent->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("\"%s\" is not partitioned",
RelationGetRelationName(parent))));
/*
* The partition constraint of the default partition depends on the
* partition bounds of every other partition. It is possible that
* another backend might be about to execute a query on the default
* partition table, and that the query relies on previously cached
* default partition constraints. We must therefore take a table lock
* strong enough to prevent all queries on the default partition from
* proceeding until we commit and send out a shared-cache-inval notice
* that will make them update their index lists.
*
* Order of locking: The relation being added won't be visible to
* other backends until it is committed, hence here in
* DefineRelation() the order of locking the default partition and the
* relation being added does not matter. But at all other places we
* need to lock the default relation before we lock the relation being
* added or removed i.e. we should take the lock in same order at all
* the places such that lock parent, lock default partition and then
* lock the partition so as to avoid a deadlock.
*/
defaultPartOid =
get_default_oid_from_partdesc(RelationGetPartitionDesc(parent));
if (OidIsValid(defaultPartOid))
defaultRel = table_open(defaultPartOid, AccessExclusiveLock);
/* Transform the bound values */
pstate = make_parsestate(NULL);
pstate->p_sourcetext = queryString;
/*
* Add an RTE containing this relation, so that transformExpr called
* on partition bound expressions is able to report errors using a
* proper context.
*/
rte = addRangeTableEntryForRelation(pstate, rel, AccessShareLock,
NULL, false, false);
addRTEtoQuery(pstate, rte, false, true, true);
bound = transformPartitionBound(pstate, parent, stmt->partbound);
/*
* Check first that the new partition's bound is valid and does not
* overlap with any of existing partitions of the parent.
*/
check_new_partition_bound(relname, parent, bound);
/*
* If the default partition exists, its partition constraints will
* change after the addition of this new partition such that it won't
* allow any row that qualifies for this new partition. So, check that
* the existing data in the default partition satisfies the constraint
* as it will exist after adding this partition.
*/
if (OidIsValid(defaultPartOid))
{
check_default_partition_contents(parent, defaultRel, bound);
/* Keep the lock until commit. */
table_close(defaultRel, NoLock);
}
/* Update the pg_class entry. */
StorePartitionBound(rel, parent, bound);
table_close(parent, NoLock);
}
/* Store inheritance information for new rel. */
StoreCatalogInheritance(relationId, inheritOids, stmt->partbound != NULL);
/*
* Process the partitioning specification (if any) and store the partition
* key information into the catalog.
*/
if (partitioned)
{
ParseState *pstate;
char strategy;
int partnatts;
AttrNumber partattrs[PARTITION_MAX_KEYS];
Oid partopclass[PARTITION_MAX_KEYS];
Oid partcollation[PARTITION_MAX_KEYS];
List *partexprs = NIL;
pstate = make_parsestate(NULL);
pstate->p_sourcetext = queryString;
partnatts = list_length(stmt->partspec->partParams);
/* Protect fixed-size arrays here and in executor */
if (partnatts > PARTITION_MAX_KEYS)
ereport(ERROR,
(errcode(ERRCODE_TOO_MANY_COLUMNS),
errmsg("cannot partition using more than %d columns",
PARTITION_MAX_KEYS)));
/*
* We need to transform the raw parsetrees corresponding to partition
* expressions into executable expression trees. Like column defaults
* and CHECK constraints, we could not have done the transformation
* earlier.
*/
stmt->partspec = transformPartitionSpec(rel, stmt->partspec,
&strategy);
ComputePartitionAttrs(pstate, rel, stmt->partspec->partParams,
partattrs, &partexprs, partopclass,
partcollation, strategy);
StorePartitionKey(rel, strategy, partnatts, partattrs, partexprs,
partopclass, partcollation);
/* make it all visible */
CommandCounterIncrement();
}
/*
* If we're creating a partition, create now all the indexes, triggers,
* FKs defined in the parent.
*
* We can't do it earlier, because DefineIndex wants to know the partition
* key which we just stored.
*/
if (stmt->partbound)
{
Oid parentId = linitial_oid(inheritOids);
Relation parent;
List *idxlist;
ListCell *cell;
/* Already have strong enough lock on the parent */
parent = table_open(parentId, NoLock);
idxlist = RelationGetIndexList(parent);
/*
* For each index in the parent table, create one in the partition
*/
foreach(cell, idxlist)
{
Relation idxRel = index_open(lfirst_oid(cell), AccessShareLock);
AttrNumber *attmap;
IndexStmt *idxstmt;
Oid constraintOid;
if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
{
if (idxRel->rd_index->indisunique)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot create foreign partition of partitioned table \"%s\"",
RelationGetRelationName(parent)),
errdetail("Table \"%s\" contains indexes that are unique.",
RelationGetRelationName(parent))));
else
{
index_close(idxRel, AccessShareLock);
continue;
}
}
attmap = convert_tuples_by_name_map(RelationGetDescr(rel),
RelationGetDescr(parent));
idxstmt =
generateClonedIndexStmt(NULL, idxRel,
attmap, RelationGetDescr(parent)->natts,
&constraintOid);
DefineIndex(RelationGetRelid(rel),
idxstmt,
InvalidOid,
RelationGetRelid(idxRel),
constraintOid,
false, false, false, false, false);
index_close(idxRel, AccessShareLock);
}
list_free(idxlist);
/*
* If there are any row-level triggers, clone them to the new
* partition.
*/
if (parent->trigdesc != NULL)
CloneRowTriggersToPartition(parent, rel);
/*
* And foreign keys too. Note that because we're freshly creating the
* table, there is no need to verify these new constraints.
*/
CloneForeignKeyConstraints(NULL, parent, rel);
table_close(parent, NoLock);
}
/*
* Now add any newly specified CHECK constraints to the new relation. Same
* as for defaults above, but these need to come after partitioning is set
* up.
*/
if (stmt->constraints)
AddRelationNewConstraints(rel, NIL, stmt->constraints,
true, true, false, queryString);
ObjectAddressSet(address, RelationRelationId, relationId);
/*
* Clean up. We keep lock on new relation (although it shouldn't be
* visible to anyone else anyway, until commit).
*/
relation_close(rel, NoLock);
return address;
}
/*
* Emit the right error or warning message for a "DROP" command issued on a
* non-existent relation
*/
static void
DropErrorMsgNonExistent(RangeVar *rel, char rightkind, bool missing_ok)
{
const struct dropmsgstrings *rentry;
if (rel->schemaname != NULL &&
!OidIsValid(LookupNamespaceNoError(rel->schemaname)))
{
if (!missing_ok)
{
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_SCHEMA),
errmsg("schema \"%s\" does not exist", rel->schemaname)));
}
else
{
ereport(NOTICE,
(errmsg("schema \"%s\" does not exist, skipping",
rel->schemaname)));
}
return;
}
for (rentry = dropmsgstringarray; rentry->kind != '\0'; rentry++)
{
if (rentry->kind == rightkind)
{
if (!missing_ok)
{
ereport(ERROR,
(errcode(rentry->nonexistent_code),
errmsg(rentry->nonexistent_msg, rel->relname)));
}
else
{
ereport(NOTICE, (errmsg(rentry->skipping_msg, rel->relname)));
break;
}
}
}
Assert(rentry->kind != '\0'); /* Should be impossible */
}
/*
* Emit the right error message for a "DROP" command issued on a
* relation of the wrong type
*/
static void
DropErrorMsgWrongType(const char *relname, char wrongkind, char rightkind)
{
const struct dropmsgstrings *rentry;
const struct dropmsgstrings *wentry;
for (rentry = dropmsgstringarray; rentry->kind != '\0'; rentry++)
if (rentry->kind == rightkind)
break;
Assert(rentry->kind != '\0');
for (wentry = dropmsgstringarray; wentry->kind != '\0'; wentry++)
if (wentry->kind == wrongkind)
break;
/* wrongkind could be something we don't have in our table... */
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg(rentry->nota_msg, relname),
(wentry->kind != '\0') ? errhint("%s", _(wentry->drophint_msg)) : 0));
}
/*
* RemoveRelations
* Implements DROP TABLE, DROP INDEX, DROP SEQUENCE, DROP VIEW,
* DROP MATERIALIZED VIEW, DROP FOREIGN TABLE
*/
void
RemoveRelations(DropStmt *drop)
{
ObjectAddresses *objects;
char relkind;
ListCell *cell;
int flags = 0;
LOCKMODE lockmode = AccessExclusiveLock;
/* DROP CONCURRENTLY uses a weaker lock, and has some restrictions */
if (drop->concurrent)
{
flags |= PERFORM_DELETION_CONCURRENTLY;
lockmode = ShareUpdateExclusiveLock;
Assert(drop->removeType == OBJECT_INDEX);
if (list_length(drop->objects) != 1)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("DROP INDEX CONCURRENTLY does not support dropping multiple objects")));
if (drop->behavior == DROP_CASCADE)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("DROP INDEX CONCURRENTLY does not support CASCADE")));
}
/*
* First we identify all the relations, then we delete them in a single
* performMultipleDeletions() call. This is to avoid unwanted DROP
* RESTRICT errors if one of the relations depends on another.
*/
/* Determine required relkind */
switch (drop->removeType)
{
case OBJECT_TABLE:
relkind = RELKIND_RELATION;
break;
case OBJECT_INDEX:
relkind = RELKIND_INDEX;
break;
case OBJECT_SEQUENCE:
relkind = RELKIND_SEQUENCE;
break;
case OBJECT_VIEW:
relkind = RELKIND_VIEW;
break;
case OBJECT_MATVIEW:
relkind = RELKIND_MATVIEW;
break;
case OBJECT_FOREIGN_TABLE:
relkind = RELKIND_FOREIGN_TABLE;
break;
default:
elog(ERROR, "unrecognized drop object type: %d",
(int) drop->removeType);
relkind = 0; /* keep compiler quiet */
break;
}
/* Lock and validate each relation; build a list of object addresses */
objects = new_object_addresses();
foreach(cell, drop->objects)
{
RangeVar *rel = makeRangeVarFromNameList((List *) lfirst(cell));
Oid relOid;
ObjectAddress obj;
struct DropRelationCallbackState state;
/*
* These next few steps are a great deal like relation_openrv, but we
* don't bother building a relcache entry since we don't need it.
*
* Check for shared-cache-inval messages before trying to access the
* relation. This is needed to cover the case where the name
* identifies a rel that has been dropped and recreated since the
* start of our transaction: if we don't flush the old syscache entry,
* then we'll latch onto that entry and suffer an error later.
*/
AcceptInvalidationMessages();
/* Look up the appropriate relation using namespace search. */
state.relkind = relkind;
state.heapOid = InvalidOid;
state.partParentOid = InvalidOid;
state.concurrent = drop->concurrent;
relOid = RangeVarGetRelidExtended(rel, lockmode, RVR_MISSING_OK,
RangeVarCallbackForDropRelation,
(void *) &state);
/* Not there? */
if (!OidIsValid(relOid))
{
DropErrorMsgNonExistent(rel, relkind, drop->missing_ok);
continue;
}
/* OK, we're ready to delete this one */
obj.classId = RelationRelationId;
obj.objectId = relOid;
obj.objectSubId = 0;
add_exact_object_address(&obj, objects);
}
performMultipleDeletions(objects, drop->behavior, flags);
free_object_addresses(objects);
}
/*
* Before acquiring a table lock, check whether we have sufficient rights.
* In the case of DROP INDEX, also try to lock the table before the index.
* Also, if the table to be dropped is a partition, we try to lock the parent
* first.
*/
static void
RangeVarCallbackForDropRelation(const RangeVar *rel, Oid relOid, Oid oldRelOid,
void *arg)
{
HeapTuple tuple;
struct DropRelationCallbackState *state;
char relkind;
char expected_relkind;
bool is_partition;
Form_pg_class classform;
LOCKMODE heap_lockmode;
bool invalid_system_index = false;
state = (struct DropRelationCallbackState *) arg;
relkind = state->relkind;
heap_lockmode = state->concurrent ?
ShareUpdateExclusiveLock : AccessExclusiveLock;
/*
* If we previously locked some other index's heap, and the name we're
* looking up no longer refers to that relation, release the now-useless
* lock.
*/
if (relOid != oldRelOid && OidIsValid(state->heapOid))
{
UnlockRelationOid(state->heapOid, heap_lockmode);
state->heapOid = InvalidOid;
}
/*
* Similarly, if we previously locked some other partition's heap, and the
* name we're looking up no longer refers to that relation, release the
* now-useless lock.
*/
if (relOid != oldRelOid && OidIsValid(state->partParentOid))
{
UnlockRelationOid(state->partParentOid, AccessExclusiveLock);
state->partParentOid = InvalidOid;
}
/* Didn't find a relation, so no need for locking or permission checks. */
if (!OidIsValid(relOid))
return;
tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relOid));
if (!HeapTupleIsValid(tuple))
return; /* concurrently dropped, so nothing to do */
classform = (Form_pg_class) GETSTRUCT(tuple);
is_partition = classform->relispartition;
/*
* Both RELKIND_RELATION and RELKIND_PARTITIONED_TABLE are OBJECT_TABLE,
* but RemoveRelations() can only pass one relkind for a given relation.
* It chooses RELKIND_RELATION for both regular and partitioned tables.
* That means we must be careful before giving the wrong type error when
* the relation is RELKIND_PARTITIONED_TABLE. An equivalent problem
* exists with indexes.
*/
if (classform->relkind == RELKIND_PARTITIONED_TABLE)
expected_relkind = RELKIND_RELATION;
else if (classform->relkind == RELKIND_PARTITIONED_INDEX)
expected_relkind = RELKIND_INDEX;
else
expected_relkind = classform->relkind;
if (relkind != expected_relkind)
DropErrorMsgWrongType(rel->relname, classform->relkind, relkind);
/* Allow DROP to either table owner or schema owner */
if (!pg_class_ownercheck(relOid, GetUserId()) &&
!pg_namespace_ownercheck(classform->relnamespace, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(relOid)),
rel->relname);
/*
* Check the case of a system index that might have been invalidated by a
* failed concurrent process and allow its drop. For the time being, this
* only concerns indexes of toast relations that became invalid during a
* REINDEX CONCURRENTLY process.
*/
if (IsSystemClass(relOid, classform) && relkind == RELKIND_INDEX)
{
HeapTuple locTuple;
Form_pg_index indexform;
bool indisvalid;
locTuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(relOid));
if (!HeapTupleIsValid(locTuple))
{
ReleaseSysCache(tuple);
return;
}
indexform = (Form_pg_index) GETSTRUCT(locTuple);
indisvalid = indexform->indisvalid;
ReleaseSysCache(locTuple);
/* Mark object as being an invalid index of system catalogs */
if (!indisvalid)
invalid_system_index = true;
}
/* In the case of an invalid index, it is fine to bypass this check */
if (!invalid_system_index && !allowSystemTableMods && IsSystemClass(relOid, classform))
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("permission denied: \"%s\" is a system catalog",
rel->relname)));
ReleaseSysCache(tuple);
/*
* In DROP INDEX, attempt to acquire lock on the parent table before
* locking the index. index_drop() will need this anyway, and since
* regular queries lock tables before their indexes, we risk deadlock if
* we do it the other way around. No error if we don't find a pg_index
* entry, though --- the relation may have been dropped.
*/
if ((relkind == RELKIND_INDEX || relkind == RELKIND_PARTITIONED_INDEX) &&
relOid != oldRelOid)
{
state->heapOid = IndexGetRelation(relOid, true);
if (OidIsValid(state->heapOid))
LockRelationOid(state->heapOid, heap_lockmode);
}
/*
* Similarly, if the relation is a partition, we must acquire lock on its
* parent before locking the partition. That's because queries lock the
* parent before its partitions, so we risk deadlock it we do it the other
* way around.
*/
if (is_partition && relOid != oldRelOid)
{
state->partParentOid = get_partition_parent(relOid);
if (OidIsValid(state->partParentOid))
LockRelationOid(state->partParentOid, AccessExclusiveLock);
}
}
/*
* ExecuteTruncate
* Executes a TRUNCATE command.
*
* This is a multi-relation truncate. We first open and grab exclusive
* lock on all relations involved, checking permissions and otherwise
* verifying that the relation is OK for truncation. In CASCADE mode,
* relations having FK references to the targeted relations are automatically
* added to the group; in RESTRICT mode, we check that all FK references are
* internal to the group that's being truncated. Finally all the relations
* are truncated and reindexed.
*/
void
ExecuteTruncate(TruncateStmt *stmt)
{
List *rels = NIL;
List *relids = NIL;
List *relids_logged = NIL;
ListCell *cell;
/*
* Open, exclusive-lock, and check all the explicitly-specified relations
*/
foreach(cell, stmt->relations)
{
RangeVar *rv = lfirst(cell);
Relation rel;
bool recurse = rv->inh;
Oid myrelid;
LOCKMODE lockmode = AccessExclusiveLock;
myrelid = RangeVarGetRelidExtended(rv, lockmode,
0, RangeVarCallbackForTruncate,
NULL);
/* open the relation, we already hold a lock on it */
rel = table_open(myrelid, NoLock);
/* don't throw error for "TRUNCATE foo, foo" */
if (list_member_oid(relids, myrelid))
{
table_close(rel, lockmode);
continue;
}
/*
* RangeVarGetRelidExtended() has done most checks with its callback,
* but other checks with the now-opened Relation remain.
*/
truncate_check_activity(rel);
rels = lappend(rels, rel);
relids = lappend_oid(relids, myrelid);
/* Log this relation only if needed for logical decoding */
if (RelationIsLogicallyLogged(rel))
relids_logged = lappend_oid(relids_logged, myrelid);
if (recurse)
{
ListCell *child;
List *children;
children = find_all_inheritors(myrelid, lockmode, NULL);
foreach(child, children)
{
Oid childrelid = lfirst_oid(child);
if (list_member_oid(relids, childrelid))
continue;
/* find_all_inheritors already got lock */
rel = table_open(childrelid, NoLock);
/*
* It is possible that the parent table has children that are
* temp tables of other backends. We cannot safely access
* such tables (because of buffering issues), and the best
* thing to do is to silently ignore them. Note that this
* check is the same as one of the checks done in
* truncate_check_activity() called below, still it is kept
* here for simplicity.
*/
if (RELATION_IS_OTHER_TEMP(rel))
{
table_close(rel, lockmode);
continue;
}
truncate_check_rel(RelationGetRelid(rel), rel->rd_rel);
truncate_check_activity(rel);
rels = lappend(rels, rel);
relids = lappend_oid(relids, childrelid);
/* Log this relation only if needed for logical decoding */
if (RelationIsLogicallyLogged(rel))
relids_logged = lappend_oid(relids_logged, childrelid);
}
}
else if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot truncate only a partitioned table"),
errhint("Do not specify the ONLY keyword, or use TRUNCATE ONLY on the partitions directly.")));
}
ExecuteTruncateGuts(rels, relids, relids_logged,
stmt->behavior, stmt->restart_seqs);
/* And close the rels */
foreach(cell, rels)
{
Relation rel = (Relation) lfirst(cell);
table_close(rel, NoLock);
}
}
/*
* ExecuteTruncateGuts
*
* Internal implementation of TRUNCATE. This is called by the actual TRUNCATE
* command (see above) as well as replication subscribers that execute a
* replicated TRUNCATE action.
*
* explicit_rels is the list of Relations to truncate that the command
* specified. relids is the list of Oids corresponding to explicit_rels.
* relids_logged is the list of Oids (a subset of relids) that require
* WAL-logging. This is all a bit redundant, but the existing callers have
* this information handy in this form.
*/
void
ExecuteTruncateGuts(List *explicit_rels, List *relids, List *relids_logged,
DropBehavior behavior, bool restart_seqs)
{
List *rels;
List *seq_relids = NIL;
EState *estate;
ResultRelInfo *resultRelInfos;
ResultRelInfo *resultRelInfo;
SubTransactionId mySubid;
ListCell *cell;
Oid *logrelids;
/*
* Check the explicitly-specified relations.
*
* In CASCADE mode, suck in all referencing relations as well. This
* requires multiple iterations to find indirectly-dependent relations. At
* each phase, we need to exclusive-lock new rels before looking for their
* dependencies, else we might miss something. Also, we check each rel as
* soon as we open it, to avoid a faux pas such as holding lock for a long
* time on a rel we have no permissions for.
*/
rels = list_copy(explicit_rels);
if (behavior == DROP_CASCADE)
{
for (;;)
{
List *newrelids;
newrelids = heap_truncate_find_FKs(relids);
if (newrelids == NIL)
break; /* nothing else to add */
foreach(cell, newrelids)
{
Oid relid = lfirst_oid(cell);
Relation rel;
rel = table_open(relid, AccessExclusiveLock);
ereport(NOTICE,
(errmsg("truncate cascades to table \"%s\"",
RelationGetRelationName(rel))));
truncate_check_rel(relid, rel->rd_rel);
truncate_check_activity(rel);
rels = lappend(rels, rel);
relids = lappend_oid(relids, relid);
/* Log this relation only if needed for logical decoding */
if (RelationIsLogicallyLogged(rel))
relids_logged = lappend_oid(relids_logged, relid);
}
}
}
/*
* Check foreign key references. In CASCADE mode, this should be
* unnecessary since we just pulled in all the references; but as a
* cross-check, do it anyway if in an Assert-enabled build.
*/
#ifdef USE_ASSERT_CHECKING
heap_truncate_check_FKs(rels, false);
#else
if (behavior == DROP_RESTRICT)
heap_truncate_check_FKs(rels, false);
#endif
/*
* If we are asked to restart sequences, find all the sequences, lock them
* (we need AccessExclusiveLock for ResetSequence), and check permissions.
* We want to do this early since it's pointless to do all the truncation
* work only to fail on sequence permissions.
*/
if (restart_seqs)
{
foreach(cell, rels)
{
Relation rel = (Relation) lfirst(cell);
List *seqlist = getOwnedSequences(RelationGetRelid(rel));
ListCell *seqcell;
foreach(seqcell, seqlist)
{
Oid seq_relid = lfirst_oid(seqcell);
Relation seq_rel;
seq_rel = relation_open(seq_relid, AccessExclusiveLock);
/* This check must match AlterSequence! */
if (!pg_class_ownercheck(seq_relid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_SEQUENCE,
RelationGetRelationName(seq_rel));
seq_relids = lappend_oid(seq_relids, seq_relid);
relation_close(seq_rel, NoLock);
}
}
}
/* Prepare to catch AFTER triggers. */
AfterTriggerBeginQuery();
/*
* To fire triggers, we'll need an EState as well as a ResultRelInfo for
* each relation. We don't need to call ExecOpenIndices, though.
*/
estate = CreateExecutorState();
resultRelInfos = (ResultRelInfo *)
palloc(list_length(rels) * sizeof(ResultRelInfo));
resultRelInfo = resultRelInfos;
foreach(cell, rels)
{
Relation rel = (Relation) lfirst(cell);
InitResultRelInfo(resultRelInfo,
rel,
0, /* dummy rangetable index */
NULL,
0);
resultRelInfo++;
}
estate->es_result_relations = resultRelInfos;
estate->es_num_result_relations = list_length(rels);
/*
* Process all BEFORE STATEMENT TRUNCATE triggers before we begin
* truncating (this is because one of them might throw an error). Also, if
* we were to allow them to prevent statement execution, that would need
* to be handled here.
*/
resultRelInfo = resultRelInfos;
foreach(cell, rels)
{
estate->es_result_relation_info = resultRelInfo;
ExecBSTruncateTriggers(estate, resultRelInfo);
resultRelInfo++;
}
/*
* OK, truncate each table.
*/
mySubid = GetCurrentSubTransactionId();
foreach(cell, rels)
{
Relation rel = (Relation) lfirst(cell);
/* Skip partitioned tables as there is nothing to do */
if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
continue;
/*
* Normally, we need a transaction-safe truncation here. However, if
* the table was either created in the current (sub)transaction or has
* a new relfilenode in the current (sub)transaction, then we can just
* truncate it in-place, because a rollback would cause the whole
* table or the current physical file to be thrown away anyway.
*/
if (rel->rd_createSubid == mySubid ||
rel->rd_newRelfilenodeSubid == mySubid)
{
/* Immediate, non-rollbackable truncation is OK */
heap_truncate_one_rel(rel);
}
else
{
Oid heap_relid;
Oid toast_relid;
/*
* This effectively deletes all rows in the table, and may be done
* in a serializable transaction. In that case we must record a
* rw-conflict in to this transaction from each transaction
* holding a predicate lock on the table.
*/
CheckTableForSerializableConflictIn(rel);
/*
* Need the full transaction-safe pushups.
*
* Create a new empty storage file for the relation, and assign it
* as the relfilenode value. The old storage file is scheduled for
* deletion at commit.
*/
RelationSetNewRelfilenode(rel, rel->rd_rel->relpersistence);
heap_relid = RelationGetRelid(rel);
/*
* The same for the toast table, if any.
*/
toast_relid = rel->rd_rel->reltoastrelid;
if (OidIsValid(toast_relid))
{
Relation toastrel = relation_open(toast_relid,
AccessExclusiveLock);
RelationSetNewRelfilenode(toastrel,
toastrel->rd_rel->relpersistence);
table_close(toastrel, NoLock);
}
/*
* Reconstruct the indexes to match, and we're done.
*/
reindex_relation(heap_relid, REINDEX_REL_PROCESS_TOAST, 0);
}
pgstat_count_truncate(rel);
}
/*
* Restart owned sequences if we were asked to.
*/
foreach(cell, seq_relids)
{
Oid seq_relid = lfirst_oid(cell);
ResetSequence(seq_relid);
}
/*
* Write a WAL record to allow this set of actions to be logically
* decoded.
*
* Assemble an array of relids so we can write a single WAL record for the
* whole action.
*/
if (list_length(relids_logged) > 0)
{
xl_heap_truncate xlrec;
int i = 0;
/* should only get here if wal_level >= logical */
Assert(XLogLogicalInfoActive());
logrelids = palloc(list_length(relids_logged) * sizeof(Oid));
foreach(cell, relids_logged)
logrelids[i++] = lfirst_oid(cell);
xlrec.dbId = MyDatabaseId;
xlrec.nrelids = list_length(relids_logged);
xlrec.flags = 0;
if (behavior == DROP_CASCADE)
xlrec.flags |= XLH_TRUNCATE_CASCADE;
if (restart_seqs)
xlrec.flags |= XLH_TRUNCATE_RESTART_SEQS;
XLogBeginInsert();
XLogRegisterData((char *) &xlrec, SizeOfHeapTruncate);
XLogRegisterData((char *) logrelids, list_length(relids_logged) * sizeof(Oid));
XLogSetRecordFlags(XLOG_INCLUDE_ORIGIN);
(void) XLogInsert(RM_HEAP_ID, XLOG_HEAP_TRUNCATE);
}
/*
* Process all AFTER STATEMENT TRUNCATE triggers.
*/
resultRelInfo = resultRelInfos;
foreach(cell, rels)
{
estate->es_result_relation_info = resultRelInfo;
ExecASTruncateTriggers(estate, resultRelInfo);
resultRelInfo++;
}
/* Handle queued AFTER triggers */
AfterTriggerEndQuery(estate);
/* We can clean up the EState now */
FreeExecutorState(estate);
/*
* Close any rels opened by CASCADE (can't do this while EState still
* holds refs)
*/
rels = list_difference_ptr(rels, explicit_rels);
foreach(cell, rels)
{
Relation rel = (Relation) lfirst(cell);
table_close(rel, NoLock);
}
}
/*
* Check that a given relation is safe to truncate. Subroutine for
* ExecuteTruncate() and RangeVarCallbackForTruncate().
*/
static void
truncate_check_rel(Oid relid, Form_pg_class reltuple)
{
AclResult aclresult;
char *relname = NameStr(reltuple->relname);
/*
* Only allow truncate on regular tables and partitioned tables (although,
* the latter are only being included here for the following checks; no
* physical truncation will occur in their case.)
*/
if (reltuple->relkind != RELKIND_RELATION &&
reltuple->relkind != RELKIND_PARTITIONED_TABLE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a table", relname)));
/* Permissions checks */
aclresult = pg_class_aclcheck(relid, GetUserId(), ACL_TRUNCATE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, get_relkind_objtype(reltuple->relkind),
relname);
if (!allowSystemTableMods && IsSystemClass(relid, reltuple))
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("permission denied: \"%s\" is a system catalog",
relname)));
}
/*
* Set of extra sanity checks to check if a given relation is safe to
* truncate. This is split with truncate_check_rel() as
* RangeVarCallbackForTruncate() cannot open a Relation yet.
*/
static void
truncate_check_activity(Relation rel)
{
/*
* Don't allow truncate on temp tables of other backends ... their local
* buffer manager is not going to cope.
*/
if (RELATION_IS_OTHER_TEMP(rel))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot truncate temporary tables of other sessions")));
/*
* Also check for active uses of the relation in the current transaction,
* including open scans and pending AFTER trigger events.
*/
CheckTableNotInUse(rel, "TRUNCATE");
}
/*
* storage_name
* returns the name corresponding to a typstorage/attstorage enum value
*/
static const char *
storage_name(char c)
{
switch (c)
{
case 'p':
return "PLAIN";
case 'm':
return "MAIN";
case 'x':
return "EXTENDED";
case 'e':
return "EXTERNAL";
default:
return "???";
}
}
/*----------
* MergeAttributes
* Returns new schema given initial schema and superclasses.
*
* Input arguments:
* 'schema' is the column/attribute definition for the table. (It's a list
* of ColumnDef's.) It is destructively changed.
* 'supers' is a list of OIDs of parent relations, already locked by caller.
* 'relpersistence' is a persistence type of the table.
* 'is_partition' tells if the table is a partition
*
* Output arguments:
* 'supconstr' receives a list of constraints belonging to the parents,
* updated as necessary to be valid for the child.
*
* Return value:
* Completed schema list.
*
* Notes:
* The order in which the attributes are inherited is very important.
* Intuitively, the inherited attributes should come first. If a table
* inherits from multiple parents, the order of those attributes are
* according to the order of the parents specified in CREATE TABLE.
*
* Here's an example:
*
* create table person (name text, age int4, location point);
* create table emp (salary int4, manager text) inherits(person);
* create table student (gpa float8) inherits (person);
* create table stud_emp (percent int4) inherits (emp, student);
*
* The order of the attributes of stud_emp is:
*
* person {1:name, 2:age, 3:location}
* / \
* {6:gpa} student emp {4:salary, 5:manager}
* \ /
* stud_emp {7:percent}
*
* If the same attribute name appears multiple times, then it appears
* in the result table in the proper location for its first appearance.
*
* Constraints (including NOT NULL constraints) for the child table
* are the union of all relevant constraints, from both the child schema
* and parent tables.
*
* The default value for a child column is defined as:
* (1) If the child schema specifies a default, that value is used.
* (2) If neither the child nor any parent specifies a default, then
* the column will not have a default.
* (3) If conflicting defaults are inherited from different parents
* (and not overridden by the child), an error is raised.
* (4) Otherwise the inherited default is used.
* Rule (3) is new in Postgres 7.1; in earlier releases you got a
* rather arbitrary choice of which parent default to use.
*----------
*/
static List *
MergeAttributes(List *schema, List *supers, char relpersistence,
bool is_partition, List **supconstr)
{
List *inhSchema = NIL;
List *constraints = NIL;
bool have_bogus_defaults = false;
int child_attno;
static Node bogus_marker = {0}; /* marks conflicting defaults */
List *saved_schema = NIL;
ListCell *entry;
/*
* Check for and reject tables with too many columns. We perform this
* check relatively early for two reasons: (a) we don't run the risk of
* overflowing an AttrNumber in subsequent code (b) an O(n^2) algorithm is
* okay if we're processing <= 1600 columns, but could take minutes to
* execute if the user attempts to create a table with hundreds of
* thousands of columns.
*
* Note that we also need to check that we do not exceed this figure after
* including columns from inherited relations.
*/
if (list_length(schema) > MaxHeapAttributeNumber)
ereport(ERROR,
(errcode(ERRCODE_TOO_MANY_COLUMNS),
errmsg("tables can have at most %d columns",
MaxHeapAttributeNumber)));
/*
* Check for duplicate names in the explicit list of attributes.
*
* Although we might consider merging such entries in the same way that we
* handle name conflicts for inherited attributes, it seems to make more
* sense to assume such conflicts are errors.
*
* We don't use foreach() here because we have two nested loops over the
* schema list, with possible element deletions in the inner one. If we
* used foreach_delete_current() it could only fix up the state of one of
* the loops, so it seems cleaner to use looping over list indexes for
* both loops. Note that any deletion will happen beyond where the outer
* loop is, so its index never needs adjustment.
*/
for (int coldefpos = 0; coldefpos < list_length(schema); coldefpos++)
{
ColumnDef *coldef = list_nth_node(ColumnDef, schema, coldefpos);
if (!is_partition && coldef->typeName == NULL)
{
/*
* Typed table column option that does not belong to a column from
* the type. This works because the columns from the type come
* first in the list. (We omit this check for partition column
* lists; those are processed separately below.)
*/
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" does not exist",
coldef->colname)));
}
/* restpos scans all entries beyond coldef; incr is in loop body */
for (int restpos = coldefpos + 1; restpos < list_length(schema);)
{
ColumnDef *restdef = list_nth_node(ColumnDef, schema, restpos);
if (strcmp(coldef->colname, restdef->colname) == 0)
{
if (coldef->is_from_type)
{
/*
* merge the column options into the column from the type
*/
coldef->is_not_null = restdef->is_not_null;
coldef->raw_default = restdef->raw_default;
coldef->cooked_default = restdef->cooked_default;
coldef->constraints = restdef->constraints;
coldef->is_from_type = false;
schema = list_delete_nth_cell(schema, restpos);
}
else
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_COLUMN),
errmsg("column \"%s\" specified more than once",
coldef->colname)));
}
else
restpos++;
}
}
/*
* In case of a partition, there are no new column definitions, only dummy
* ColumnDefs created for column constraints. Set them aside for now and
* process them at the end.
*/
if (is_partition)
{
saved_schema = schema;
schema = NIL;
}
/*
* Scan the parents left-to-right, and merge their attributes to form a
* list of inherited attributes (inhSchema). Also check to see if we need
* to inherit an OID column.
*/
child_attno = 0;
foreach(entry, supers)
{
Oid parent = lfirst_oid(entry);
Relation relation;
TupleDesc tupleDesc;
TupleConstr *constr;
AttrNumber *newattno;
AttrNumber parent_attno;
/* caller already got lock */
relation = table_open(parent, NoLock);
/*
* Check for active uses of the parent partitioned table in the
* current transaction, such as being used in some manner by an
* enclosing command.
*/
if (is_partition)
CheckTableNotInUse(relation, "CREATE TABLE .. PARTITION OF");
/*
* We do not allow partitioned tables and partitions to participate in
* regular inheritance.
*/
if (relation->rd_rel->relkind == RELKIND_PARTITIONED_TABLE &&
!is_partition)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot inherit from partitioned table \"%s\"",
RelationGetRelationName(relation))));
if (relation->rd_rel->relispartition && !is_partition)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot inherit from partition \"%s\"",
RelationGetRelationName(relation))));
if (relation->rd_rel->relkind != RELKIND_RELATION &&
relation->rd_rel->relkind != RELKIND_FOREIGN_TABLE &&
relation->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("inherited relation \"%s\" is not a table or foreign table",
RelationGetRelationName(relation))));
/*
* If the parent is permanent, so must be all of its partitions. Note
* that inheritance allows that case.
*/
if (is_partition &&
relation->rd_rel->relpersistence != RELPERSISTENCE_TEMP &&
relpersistence == RELPERSISTENCE_TEMP)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot create a temporary relation as partition of permanent relation \"%s\"",
RelationGetRelationName(relation))));
/* Permanent rels cannot inherit from temporary ones */
if (relpersistence != RELPERSISTENCE_TEMP &&
relation->rd_rel->relpersistence == RELPERSISTENCE_TEMP)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg(!is_partition
? "cannot inherit from temporary relation \"%s\""
: "cannot create a permanent relation as partition of temporary relation \"%s\"",
RelationGetRelationName(relation))));
/* If existing rel is temp, it must belong to this session */
if (relation->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
!relation->rd_islocaltemp)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg(!is_partition
? "cannot inherit from temporary relation of another session"
: "cannot create as partition of temporary relation of another session")));
/*
* We should have an UNDER permission flag for this, but for now,
* demand that creator of a child table own the parent.
*/
if (!pg_class_ownercheck(RelationGetRelid(relation), GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(relation->rd_rel->relkind),
RelationGetRelationName(relation));
tupleDesc = RelationGetDescr(relation);
constr = tupleDesc->constr;
/*
* newattno[] will contain the child-table attribute numbers for the
* attributes of this parent table. (They are not the same for
* parents after the first one, nor if we have dropped columns.)
*/
newattno = (AttrNumber *)
palloc0(tupleDesc->natts * sizeof(AttrNumber));
for (parent_attno = 1; parent_attno <= tupleDesc->natts;
parent_attno++)
{
Form_pg_attribute attribute = TupleDescAttr(tupleDesc,
parent_attno - 1);
char *attributeName = NameStr(attribute->attname);
int exist_attno;
ColumnDef *def;
/*
* Ignore dropped columns in the parent.
*/
if (attribute->attisdropped)
continue; /* leave newattno entry as zero */
/*
* Does it conflict with some previously inherited column?
*/
exist_attno = findAttrByName(attributeName, inhSchema);
if (exist_attno > 0)
{
Oid defTypeId;
int32 deftypmod;
Oid defCollId;
/*
* Yes, try to merge the two column definitions. They must
* have the same type, typmod, and collation.
*/
ereport(NOTICE,
(errmsg("merging multiple inherited definitions of column \"%s\"",
attributeName)));
def = (ColumnDef *) list_nth(inhSchema, exist_attno - 1);
typenameTypeIdAndMod(NULL, def->typeName, &defTypeId, &deftypmod);
if (defTypeId != attribute->atttypid ||
deftypmod != attribute->atttypmod)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("inherited column \"%s\" has a type conflict",
attributeName),
errdetail("%s versus %s",
format_type_with_typemod(defTypeId,
deftypmod),
format_type_with_typemod(attribute->atttypid,
attribute->atttypmod))));
defCollId = GetColumnDefCollation(NULL, def, defTypeId);
if (defCollId != attribute->attcollation)
ereport(ERROR,
(errcode(ERRCODE_COLLATION_MISMATCH),
errmsg("inherited column \"%s\" has a collation conflict",
attributeName),
errdetail("\"%s\" versus \"%s\"",
get_collation_name(defCollId),
get_collation_name(attribute->attcollation))));
/* Copy storage parameter */
if (def->storage == 0)
def->storage = attribute->attstorage;
else if (def->storage != attribute->attstorage)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("inherited column \"%s\" has a storage parameter conflict",
attributeName),
errdetail("%s versus %s",
storage_name(def->storage),
storage_name(attribute->attstorage))));
def->inhcount++;
/* Merge of NOT NULL constraints = OR 'em together */
def->is_not_null |= attribute->attnotnull;
/* Default and other constraints are handled below */
newattno[parent_attno - 1] = exist_attno;
/* Check for GENERATED conflicts */
if (def->generated != attribute->attgenerated)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("inherited column \"%s\" has a generation conflict",
attributeName)));
}
else
{
/*
* No, create a new inherited column
*/
def = makeNode(ColumnDef);
def->colname = pstrdup(attributeName);
def->typeName = makeTypeNameFromOid(attribute->atttypid,
attribute->atttypmod);
def->inhcount = 1;
def->is_local = false;
def->is_not_null = attribute->attnotnull;
def->is_from_type = false;
def->storage = attribute->attstorage;
def->raw_default = NULL;
def->cooked_default = NULL;
def->generated = attribute->attgenerated;
def->collClause = NULL;
def->collOid = attribute->attcollation;
def->constraints = NIL;
def->location = -1;
inhSchema = lappend(inhSchema, def);
newattno[parent_attno - 1] = ++child_attno;
}
/*
* Copy default if any
*/
if (attribute->atthasdef)
{
Node *this_default = NULL;
AttrDefault *attrdef;
int i;
/* Find default in constraint structure */
Assert(constr != NULL);
attrdef = constr->defval;
for (i = 0; i < constr->num_defval; i++)
{
if (attrdef[i].adnum == parent_attno)
{
this_default = stringToNode(attrdef[i].adbin);
break;
}
}
Assert(this_default != NULL);
/*
* If default expr could contain any vars, we'd need to fix
* 'em, but it can't; so default is ready to apply to child.
*
* If we already had a default from some prior parent, check
* to see if they are the same. If so, no problem; if not,
* mark the column as having a bogus default. Below, we will
* complain if the bogus default isn't overridden by the child
* schema.
*/
Assert(def->raw_default == NULL);
if (def->cooked_default == NULL)
def->cooked_default = this_default;
else if (!equal(def->cooked_default, this_default))
{
def->cooked_default = &bogus_marker;
have_bogus_defaults = true;
}
}
}
/*
* Now copy the CHECK constraints of this parent, adjusting attnos
* using the completed newattno[] map. Identically named constraints
* are merged if possible, else we throw error.
*/
if (constr && constr->num_check > 0)
{
ConstrCheck *check = constr->check;
int i;
for (i = 0; i < constr->num_check; i++)
{
char *name = check[i].ccname;
Node *expr;
bool found_whole_row;
/* ignore if the constraint is non-inheritable */
if (check[i].ccnoinherit)
continue;
/* Adjust Vars to match new table's column numbering */
expr = map_variable_attnos(stringToNode(check[i].ccbin),
1, 0,
newattno, tupleDesc->natts,
InvalidOid, &found_whole_row);
/*
* For the moment we have to reject whole-row variables. We
* could convert them, if we knew the new table's rowtype OID,
* but that hasn't been assigned yet.
*/
if (found_whole_row)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot convert whole-row table reference"),
errdetail("Constraint \"%s\" contains a whole-row reference to table \"%s\".",
name,
RelationGetRelationName(relation))));
/* check for duplicate */
if (!MergeCheckConstraint(constraints, name, expr))
{
/* nope, this is a new one */
CookedConstraint *cooked;
cooked = (CookedConstraint *) palloc(sizeof(CookedConstraint));
cooked->contype = CONSTR_CHECK;
cooked->conoid = InvalidOid; /* until created */
cooked->name = pstrdup(name);
cooked->attnum = 0; /* not used for constraints */
cooked->expr = expr;
cooked->skip_validation = false;
cooked->is_local = false;
cooked->inhcount = 1;
cooked->is_no_inherit = false;
constraints = lappend(constraints, cooked);
}
}
}
pfree(newattno);
/*
* Close the parent rel, but keep our lock on it until xact commit.
* That will prevent someone else from deleting or ALTERing the parent
* before the child is committed.
*/
table_close(relation, NoLock);
}
/*
* If we had no inherited attributes, the result schema is just the
* explicitly declared columns. Otherwise, we need to merge the declared
* columns into the inherited schema list. Although, we never have any
* explicitly declared columns if the table is a partition.
*/
if (inhSchema != NIL)
{
int schema_attno = 0;
foreach(entry, schema)
{
ColumnDef *newdef = lfirst(entry);
char *attributeName = newdef->colname;
int exist_attno;
schema_attno++;
/*
* Does it conflict with some previously inherited column?
*/
exist_attno = findAttrByName(attributeName, inhSchema);
if (exist_attno > 0)
{
ColumnDef *def;
Oid defTypeId,
newTypeId;
int32 deftypmod,
newtypmod;
Oid defcollid,
newcollid;
/*
* Partitions have only one parent and have no column
* definitions of their own, so conflict should never occur.
*/
Assert(!is_partition);
/*
* Yes, try to merge the two column definitions. They must
* have the same type, typmod, and collation.
*/
if (exist_attno == schema_attno)
ereport(NOTICE,
(errmsg("merging column \"%s\" with inherited definition",
attributeName)));
else
ereport(NOTICE,
(errmsg("moving and merging column \"%s\" with inherited definition", attributeName),
errdetail("User-specified column moved to the position of the inherited column.")));
def = (ColumnDef *) list_nth(inhSchema, exist_attno - 1);
typenameTypeIdAndMod(NULL, def->typeName, &defTypeId, &deftypmod);
typenameTypeIdAndMod(NULL, newdef->typeName, &newTypeId, &newtypmod);
if (defTypeId != newTypeId || deftypmod != newtypmod)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("column \"%s\" has a type conflict",
attributeName),
errdetail("%s versus %s",
format_type_with_typemod(defTypeId,
deftypmod),
format_type_with_typemod(newTypeId,
newtypmod))));
defcollid = GetColumnDefCollation(NULL, def, defTypeId);
newcollid = GetColumnDefCollation(NULL, newdef, newTypeId);
if (defcollid != newcollid)
ereport(ERROR,
(errcode(ERRCODE_COLLATION_MISMATCH),
errmsg("column \"%s\" has a collation conflict",
attributeName),
errdetail("\"%s\" versus \"%s\"",
get_collation_name(defcollid),
get_collation_name(newcollid))));
/*
* Identity is never inherited. The new column can have an
* identity definition, so we always just take that one.
*/
def->identity = newdef->identity;
/* Copy storage parameter */
if (def->storage == 0)
def->storage = newdef->storage;
else if (newdef->storage != 0 && def->storage != newdef->storage)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("column \"%s\" has a storage parameter conflict",
attributeName),
errdetail("%s versus %s",
storage_name(def->storage),
storage_name(newdef->storage))));
/* Mark the column as locally defined */
def->is_local = true;
/* Merge of NOT NULL constraints = OR 'em together */
def->is_not_null |= newdef->is_not_null;
/* If new def has a default, override previous default */
if (newdef->raw_default != NULL)
{
def->raw_default = newdef->raw_default;
def->cooked_default = newdef->cooked_default;
}
}
else
{
/*
* No, attach new column to result schema
*/
inhSchema = lappend(inhSchema, newdef);
}
}
schema = inhSchema;
/*
* Check that we haven't exceeded the legal # of columns after merging
* in inherited columns.
*/
if (list_length(schema) > MaxHeapAttributeNumber)
ereport(ERROR,
(errcode(ERRCODE_TOO_MANY_COLUMNS),
errmsg("tables can have at most %d columns",
MaxHeapAttributeNumber)));
}
/*
* Now that we have the column definition list for a partition, we can
* check whether the columns referenced in the column constraint specs
* actually exist. Also, we merge NOT NULL and defaults into each
* corresponding column definition.
*/
if (is_partition)
{
foreach(entry, saved_schema)
{
ColumnDef *restdef = lfirst(entry);
bool found = false;
ListCell *l;
foreach(l, schema)
{
ColumnDef *coldef = lfirst(l);
if (strcmp(coldef->colname, restdef->colname) == 0)
{
found = true;
coldef->is_not_null |= restdef->is_not_null;
/*
* Override the parent's default value for this column
* (coldef->cooked_default) with the partition's local
* definition (restdef->raw_default), if there's one. It
* should be physically impossible to get a cooked default
* in the local definition or a raw default in the
* inherited definition, but make sure they're nulls, for
* future-proofing.
*/
Assert(restdef->cooked_default == NULL);
Assert(coldef->raw_default == NULL);
if (restdef->raw_default)
{
coldef->raw_default = restdef->raw_default;
coldef->cooked_default = NULL;
}
}
}
/* complain for constraints on columns not in parent */
if (!found)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" does not exist",
restdef->colname)));
}
}
/*
* If we found any conflicting parent default values, check to make sure
* they were overridden by the child.
*/
if (have_bogus_defaults)
{
foreach(entry, schema)
{
ColumnDef *def = lfirst(entry);
if (def->cooked_default == &bogus_marker)
ereport(ERROR,
(errcode(ERRCODE_INVALID_COLUMN_DEFINITION),
errmsg("column \"%s\" inherits conflicting default values",
def->colname),
errhint("To resolve the conflict, specify a default explicitly.")));
}
}
*supconstr = constraints;
return schema;
}
/*
* MergeCheckConstraint
* Try to merge an inherited CHECK constraint with previous ones
*
* If we inherit identically-named constraints from multiple parents, we must
* merge them, or throw an error if they don't have identical definitions.
*
* constraints is a list of CookedConstraint structs for previous constraints.
*
* Returns true if merged (constraint is a duplicate), or false if it's
* got a so-far-unique name, or throws error if conflict.
*/
static bool
MergeCheckConstraint(List *constraints, char *name, Node *expr)
{
ListCell *lc;
foreach(lc, constraints)
{
CookedConstraint *ccon = (CookedConstraint *) lfirst(lc);
Assert(ccon->contype == CONSTR_CHECK);
/* Non-matching names never conflict */
if (strcmp(ccon->name, name) != 0)
continue;
if (equal(expr, ccon->expr))
{
/* OK to merge */
ccon->inhcount++;
return true;
}
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_OBJECT),
errmsg("check constraint name \"%s\" appears multiple times but with different expressions",
name)));
}
return false;
}
/*
* StoreCatalogInheritance
* Updates the system catalogs with proper inheritance information.
*
* supers is a list of the OIDs of the new relation's direct ancestors.
*/
static void
StoreCatalogInheritance(Oid relationId, List *supers,
bool child_is_partition)
{
Relation relation;
int32 seqNumber;
ListCell *entry;
/*
* sanity checks
*/
AssertArg(OidIsValid(relationId));
if (supers == NIL)
return;
/*
* Store INHERITS information in pg_inherits using direct ancestors only.
* Also enter dependencies on the direct ancestors, and make sure they are
* marked with relhassubclass = true.
*
* (Once upon a time, both direct and indirect ancestors were found here
* and then entered into pg_ipl. Since that catalog doesn't exist
* anymore, there's no need to look for indirect ancestors.)
*/
relation = table_open(InheritsRelationId, RowExclusiveLock);
seqNumber = 1;
foreach(entry, supers)
{
Oid parentOid = lfirst_oid(entry);
StoreCatalogInheritance1(relationId, parentOid, seqNumber, relation,
child_is_partition);
seqNumber++;
}
table_close(relation, RowExclusiveLock);
}
/*
* Make catalog entries showing relationId as being an inheritance child
* of parentOid. inhRelation is the already-opened pg_inherits catalog.
*/
static void
StoreCatalogInheritance1(Oid relationId, Oid parentOid,
int32 seqNumber, Relation inhRelation,
bool child_is_partition)
{
ObjectAddress childobject,
parentobject;
/* store the pg_inherits row */
StoreSingleInheritance(relationId, parentOid, seqNumber);
/*
* Store a dependency too
*/
parentobject.classId = RelationRelationId;
parentobject.objectId = parentOid;
parentobject.objectSubId = 0;
childobject.classId = RelationRelationId;
childobject.objectId = relationId;
childobject.objectSubId = 0;
recordDependencyOn(&childobject, &parentobject,
child_dependency_type(child_is_partition));
/*
* Post creation hook of this inheritance. Since object_access_hook
* doesn't take multiple object identifiers, we relay oid of parent
* relation using auxiliary_id argument.
*/
InvokeObjectPostAlterHookArg(InheritsRelationId,
relationId, 0,
parentOid, false);
/*
* Mark the parent as having subclasses.
*/
SetRelationHasSubclass(parentOid, true);
}
/*
* Look for an existing schema entry with the given name.
*
* Returns the index (starting with 1) if attribute already exists in schema,
* 0 if it doesn't.
*/
static int
findAttrByName(const char *attributeName, List *schema)
{
ListCell *s;
int i = 1;
foreach(s, schema)
{
ColumnDef *def = lfirst(s);
if (strcmp(attributeName, def->colname) == 0)
return i;
i++;
}
return 0;
}
/*
* SetRelationHasSubclass
* Set the value of the relation's relhassubclass field in pg_class.
*
* NOTE: caller must be holding an appropriate lock on the relation.
* ShareUpdateExclusiveLock is sufficient.
*
* NOTE: an important side-effect of this operation is that an SI invalidation
* message is sent out to all backends --- including me --- causing plans
* referencing the relation to be rebuilt with the new list of children.
* This must happen even if we find that no change is needed in the pg_class
* row.
*/
void
SetRelationHasSubclass(Oid relationId, bool relhassubclass)
{
Relation relationRelation;
HeapTuple tuple;
Form_pg_class classtuple;
/*
* Fetch a modifiable copy of the tuple, modify it, update pg_class.
*/
relationRelation = table_open(RelationRelationId, RowExclusiveLock);
tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relationId));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for relation %u", relationId);
classtuple = (Form_pg_class) GETSTRUCT(tuple);
if (classtuple->relhassubclass != relhassubclass)
{
classtuple->relhassubclass = relhassubclass;
CatalogTupleUpdate(relationRelation, &tuple->t_self, tuple);
}
else
{
/* no need to change tuple, but force relcache rebuild anyway */
CacheInvalidateRelcacheByTuple(tuple);
}
heap_freetuple(tuple);
table_close(relationRelation, RowExclusiveLock);
}
/*
* renameatt_check - basic sanity checks before attribute rename
*/
static void
renameatt_check(Oid myrelid, Form_pg_class classform, bool recursing)
{
char relkind = classform->relkind;
if (classform->reloftype && !recursing)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot rename column of typed table")));
/*
* Renaming the columns of sequences or toast tables doesn't actually
* break anything from the system's point of view, since internal
* references are by attnum. But it doesn't seem right to allow users to
* change names that are hardcoded into the system, hence the following
* restriction.
*/
if (relkind != RELKIND_RELATION &&
relkind != RELKIND_VIEW &&
relkind != RELKIND_MATVIEW &&
relkind != RELKIND_COMPOSITE_TYPE &&
relkind != RELKIND_INDEX &&
relkind != RELKIND_PARTITIONED_INDEX &&
relkind != RELKIND_FOREIGN_TABLE &&
relkind != RELKIND_PARTITIONED_TABLE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a table, view, materialized view, composite type, index, or foreign table",
NameStr(classform->relname))));
/*
* permissions checking. only the owner of a class can change its schema.
*/
if (!pg_class_ownercheck(myrelid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(myrelid)),
NameStr(classform->relname));
if (!allowSystemTableMods && IsSystemClass(myrelid, classform))
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("permission denied: \"%s\" is a system catalog",
NameStr(classform->relname))));
}
/*
* renameatt_internal - workhorse for renameatt
*
* Return value is the attribute number in the 'myrelid' relation.
*/
static AttrNumber
renameatt_internal(Oid myrelid,
const char *oldattname,
const char *newattname,
bool recurse,
bool recursing,
int expected_parents,
DropBehavior behavior)
{
Relation targetrelation;
Relation attrelation;
HeapTuple atttup;
Form_pg_attribute attform;
AttrNumber attnum;
/*
* Grab an exclusive lock on the target table, which we will NOT release
* until end of transaction.
*/
targetrelation = relation_open(myrelid, AccessExclusiveLock);
renameatt_check(myrelid, RelationGetForm(targetrelation), recursing);
/*
* if the 'recurse' flag is set then we are supposed to rename this
* attribute in all classes that inherit from 'relname' (as well as in
* 'relname').
*
* any permissions or problems with duplicate attributes will cause the
* whole transaction to abort, which is what we want -- all or nothing.
*/
if (recurse)
{
List *child_oids,
*child_numparents;
ListCell *lo,
*li;
/*
* we need the number of parents for each child so that the recursive
* calls to renameatt() can determine whether there are any parents
* outside the inheritance hierarchy being processed.
*/
child_oids = find_all_inheritors(myrelid, AccessExclusiveLock,
&child_numparents);
/*
* find_all_inheritors does the recursive search of the inheritance
* hierarchy, so all we have to do is process all of the relids in the
* list that it returns.
*/
forboth(lo, child_oids, li, child_numparents)
{
Oid childrelid = lfirst_oid(lo);
int numparents = lfirst_int(li);
if (childrelid == myrelid)
continue;
/* note we need not recurse again */
renameatt_internal(childrelid, oldattname, newattname, false, true, numparents, behavior);
}
}
else
{
/*
* If we are told not to recurse, there had better not be any child
* tables; else the rename would put them out of step.
*
* expected_parents will only be 0 if we are not already recursing.
*/
if (expected_parents == 0 &&
find_inheritance_children(myrelid, NoLock) != NIL)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("inherited column \"%s\" must be renamed in child tables too",
oldattname)));
}
/* rename attributes in typed tables of composite type */
if (targetrelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
{
List *child_oids;
ListCell *lo;
child_oids = find_typed_table_dependencies(targetrelation->rd_rel->reltype,
RelationGetRelationName(targetrelation),
behavior);
foreach(lo, child_oids)
renameatt_internal(lfirst_oid(lo), oldattname, newattname, true, true, 0, behavior);
}
attrelation = table_open(AttributeRelationId, RowExclusiveLock);
atttup = SearchSysCacheCopyAttName(myrelid, oldattname);
if (!HeapTupleIsValid(atttup))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" does not exist",
oldattname)));
attform = (Form_pg_attribute) GETSTRUCT(atttup);
attnum = attform->attnum;
if (attnum <= 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot rename system column \"%s\"",
oldattname)));
/*
* if the attribute is inherited, forbid the renaming. if this is a
* top-level call to renameatt(), then expected_parents will be 0, so the
* effect of this code will be to prohibit the renaming if the attribute
* is inherited at all. if this is a recursive call to renameatt(),
* expected_parents will be the number of parents the current relation has
* within the inheritance hierarchy being processed, so we'll prohibit the
* renaming only if there are additional parents from elsewhere.
*/
if (attform->attinhcount > expected_parents)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("cannot rename inherited column \"%s\"",
oldattname)));
/* new name should not already exist */
(void) check_for_column_name_collision(targetrelation, newattname, false);
/* apply the update */
namestrcpy(&(attform->attname), newattname);
CatalogTupleUpdate(attrelation, &atttup->t_self, atttup);
InvokeObjectPostAlterHook(RelationRelationId, myrelid, attnum);
heap_freetuple(atttup);
table_close(attrelation, RowExclusiveLock);
relation_close(targetrelation, NoLock); /* close rel but keep lock */
return attnum;
}
/*
* Perform permissions and integrity checks before acquiring a relation lock.
*/
static void
RangeVarCallbackForRenameAttribute(const RangeVar *rv, Oid relid, Oid oldrelid,
void *arg)
{
HeapTuple tuple;
Form_pg_class form;
tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
if (!HeapTupleIsValid(tuple))
return; /* concurrently dropped */
form = (Form_pg_class) GETSTRUCT(tuple);
renameatt_check(relid, form, false);
ReleaseSysCache(tuple);
}
/*
* renameatt - changes the name of an attribute in a relation
*
* The returned ObjectAddress is that of the renamed column.
*/
ObjectAddress
renameatt(RenameStmt *stmt)
{
Oid relid;
AttrNumber attnum;
ObjectAddress address;
/* lock level taken here should match renameatt_internal */
relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock,
stmt->missing_ok ? RVR_MISSING_OK : 0,
RangeVarCallbackForRenameAttribute,
NULL);
if (!OidIsValid(relid))
{
ereport(NOTICE,
(errmsg("relation \"%s\" does not exist, skipping",
stmt->relation->relname)));
return InvalidObjectAddress;
}
attnum =
renameatt_internal(relid,
stmt->subname, /* old att name */
stmt->newname, /* new att name */
stmt->relation->inh, /* recursive? */
false, /* recursing? */
0, /* expected inhcount */
stmt->behavior);
ObjectAddressSubSet(address, RelationRelationId, relid, attnum);
return address;
}
/*
* same logic as renameatt_internal
*/
static ObjectAddress
rename_constraint_internal(Oid myrelid,
Oid mytypid,
const char *oldconname,
const char *newconname,
bool recurse,
bool recursing,
int expected_parents)
{
Relation targetrelation = NULL;
Oid constraintOid;
HeapTuple tuple;
Form_pg_constraint con;
ObjectAddress address;
AssertArg(!myrelid || !mytypid);
if (mytypid)
{
constraintOid = get_domain_constraint_oid(mytypid, oldconname, false);
}
else
{
targetrelation = relation_open(myrelid, AccessExclusiveLock);
/*
* don't tell it whether we're recursing; we allow changing typed
* tables here
*/
renameatt_check(myrelid, RelationGetForm(targetrelation), false);
constraintOid = get_relation_constraint_oid(myrelid, oldconname, false);
}
tuple = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constraintOid));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for constraint %u",
constraintOid);
con = (Form_pg_constraint) GETSTRUCT(tuple);
if (myrelid && con->contype == CONSTRAINT_CHECK && !con->connoinherit)
{
if (recurse)
{
List *child_oids,
*child_numparents;
ListCell *lo,
*li;
child_oids = find_all_inheritors(myrelid, AccessExclusiveLock,
&child_numparents);
forboth(lo, child_oids, li, child_numparents)
{
Oid childrelid = lfirst_oid(lo);
int numparents = lfirst_int(li);
if (childrelid == myrelid)
continue;
rename_constraint_internal(childrelid, InvalidOid, oldconname, newconname, false, true, numparents);
}
}
else
{
if (expected_parents == 0 &&
find_inheritance_children(myrelid, NoLock) != NIL)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("inherited constraint \"%s\" must be renamed in child tables too",
oldconname)));
}
if (con->coninhcount > expected_parents)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("cannot rename inherited constraint \"%s\"",
oldconname)));
}
if (con->conindid
&& (con->contype == CONSTRAINT_PRIMARY
|| con->contype == CONSTRAINT_UNIQUE
|| con->contype == CONSTRAINT_EXCLUSION))
/* rename the index; this renames the constraint as well */
RenameRelationInternal(con->conindid, newconname, false, true);
else
RenameConstraintById(constraintOid, newconname);
ObjectAddressSet(address, ConstraintRelationId, constraintOid);
ReleaseSysCache(tuple);
if (targetrelation)
{
/*
* Invalidate relcache so as others can see the new constraint name.
*/
CacheInvalidateRelcache(targetrelation);
relation_close(targetrelation, NoLock); /* close rel but keep lock */
}
return address;
}
ObjectAddress
RenameConstraint(RenameStmt *stmt)
{
Oid relid = InvalidOid;
Oid typid = InvalidOid;
if (stmt->renameType == OBJECT_DOMCONSTRAINT)
{
Relation rel;
HeapTuple tup;
typid = typenameTypeId(NULL, makeTypeNameFromNameList(castNode(List, stmt->object)));
rel = table_open(TypeRelationId, RowExclusiveLock);
tup = SearchSysCache1(TYPEOID, ObjectIdGetDatum(typid));
if (!HeapTupleIsValid(tup))
elog(ERROR, "cache lookup failed for type %u", typid);
checkDomainOwner(tup);
ReleaseSysCache(tup);
table_close(rel, NoLock);
}
else
{
/* lock level taken here should match rename_constraint_internal */
relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock,
stmt->missing_ok ? RVR_MISSING_OK : 0,
RangeVarCallbackForRenameAttribute,
NULL);
if (!OidIsValid(relid))
{
ereport(NOTICE,
(errmsg("relation \"%s\" does not exist, skipping",
stmt->relation->relname)));
return InvalidObjectAddress;
}
}
return
rename_constraint_internal(relid, typid,
stmt->subname,
stmt->newname,
(stmt->relation &&
stmt->relation->inh), /* recursive? */
false, /* recursing? */
0 /* expected inhcount */ );
}
/*
* Execute ALTER TABLE/INDEX/SEQUENCE/VIEW/MATERIALIZED VIEW/FOREIGN TABLE
* RENAME
*/
ObjectAddress
RenameRelation(RenameStmt *stmt)
{
bool is_index = stmt->renameType == OBJECT_INDEX;
Oid relid;
ObjectAddress address;
/*
* Grab an exclusive lock on the target table, index, sequence, view,
* materialized view, or foreign table, which we will NOT release until
* end of transaction.
*
* Lock level used here should match RenameRelationInternal, to avoid lock
* escalation.
*/
relid = RangeVarGetRelidExtended(stmt->relation,
is_index ? ShareUpdateExclusiveLock : AccessExclusiveLock,
stmt->missing_ok ? RVR_MISSING_OK : 0,
RangeVarCallbackForAlterRelation,
(void *) stmt);
if (!OidIsValid(relid))
{
ereport(NOTICE,
(errmsg("relation \"%s\" does not exist, skipping",
stmt->relation->relname)));
return InvalidObjectAddress;
}
/* Do the work */
RenameRelationInternal(relid, stmt->newname, false, is_index);
ObjectAddressSet(address, RelationRelationId, relid);
return address;
}
/*
* RenameRelationInternal - change the name of a relation
*/
void
RenameRelationInternal(Oid myrelid, const char *newrelname, bool is_internal, bool is_index)
{
Relation targetrelation;
Relation relrelation; /* for RELATION relation */
HeapTuple reltup;
Form_pg_class relform;
Oid namespaceId;
/*
* Grab a lock on the target relation, which we will NOT release until end
* of transaction. We need at least a self-exclusive lock so that
* concurrent DDL doesn't overwrite the rename if they start updating
* while still seeing the old version. The lock also guards against
* triggering relcache reloads in concurrent sessions, which might not
* handle this information changing under them. For indexes, we can use a
* reduced lock level because RelationReloadIndexInfo() handles indexes
* specially.
*/
targetrelation = relation_open(myrelid, is_index ? ShareUpdateExclusiveLock : AccessExclusiveLock);
namespaceId = RelationGetNamespace(targetrelation);
/*
* Find relation's pg_class tuple, and make sure newrelname isn't in use.
*/
relrelation = table_open(RelationRelationId, RowExclusiveLock);
reltup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(myrelid));
if (!HeapTupleIsValid(reltup)) /* shouldn't happen */
elog(ERROR, "cache lookup failed for relation %u", myrelid);
relform = (Form_pg_class) GETSTRUCT(reltup);
if (get_relname_relid(newrelname, namespaceId) != InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_TABLE),
errmsg("relation \"%s\" already exists",
newrelname)));
/*
* Update pg_class tuple with new relname. (Scribbling on reltup is OK
* because it's a copy...)
*/
namestrcpy(&(relform->relname), newrelname);
CatalogTupleUpdate(relrelation, &reltup->t_self, reltup);
InvokeObjectPostAlterHookArg(RelationRelationId, myrelid, 0,
InvalidOid, is_internal);
heap_freetuple(reltup);
table_close(relrelation, RowExclusiveLock);
/*
* Also rename the associated type, if any.
*/
if (OidIsValid(targetrelation->rd_rel->reltype))
RenameTypeInternal(targetrelation->rd_rel->reltype,
newrelname, namespaceId);
/*
* Also rename the associated constraint, if any.
*/
if (targetrelation->rd_rel->relkind == RELKIND_INDEX ||
targetrelation->rd_rel->relkind == RELKIND_PARTITIONED_INDEX)
{
Oid constraintId = get_index_constraint(myrelid);
if (OidIsValid(constraintId))
RenameConstraintById(constraintId, newrelname);
}
/*
* Close rel, but keep lock!
*/
relation_close(targetrelation, NoLock);
}
/*
* Disallow ALTER TABLE (and similar commands) when the current backend has
* any open reference to the target table besides the one just acquired by
* the calling command; this implies there's an open cursor or active plan.
* We need this check because our lock doesn't protect us against stomping
* on our own foot, only other people's feet!
*
* For ALTER TABLE, the only case known to cause serious trouble is ALTER
* COLUMN TYPE, and some changes are obviously pretty benign, so this could
* possibly be relaxed to only error out for certain types of alterations.
* But the use-case for allowing any of these things is not obvious, so we
* won't work hard at it for now.
*
* We also reject these commands if there are any pending AFTER trigger events
* for the rel. This is certainly necessary for the rewriting variants of
* ALTER TABLE, because they don't preserve tuple TIDs and so the pending
* events would try to fetch the wrong tuples. It might be overly cautious
* in other cases, but again it seems better to err on the side of paranoia.
*
* REINDEX calls this with "rel" referencing the index to be rebuilt; here
* we are worried about active indexscans on the index. The trigger-event
* check can be skipped, since we are doing no damage to the parent table.
*
* The statement name (eg, "ALTER TABLE") is passed for use in error messages.
*/
void
CheckTableNotInUse(Relation rel, const char *stmt)
{
int expected_refcnt;
expected_refcnt = rel->rd_isnailed ? 2 : 1;
if (rel->rd_refcnt != expected_refcnt)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_IN_USE),
/* translator: first %s is a SQL command, eg ALTER TABLE */
errmsg("cannot %s \"%s\" because it is being used by active queries in this session",
stmt, RelationGetRelationName(rel))));
if (rel->rd_rel->relkind != RELKIND_INDEX &&
rel->rd_rel->relkind != RELKIND_PARTITIONED_INDEX &&
AfterTriggerPendingOnRel(RelationGetRelid(rel)))
ereport(ERROR,
(errcode(ERRCODE_OBJECT_IN_USE),
/* translator: first %s is a SQL command, eg ALTER TABLE */
errmsg("cannot %s \"%s\" because it has pending trigger events",
stmt, RelationGetRelationName(rel))));
}
/*
* AlterTableLookupRelation
* Look up, and lock, the OID for the relation named by an alter table
* statement.
*/
Oid
AlterTableLookupRelation(AlterTableStmt *stmt, LOCKMODE lockmode)
{
return RangeVarGetRelidExtended(stmt->relation, lockmode,
stmt->missing_ok ? RVR_MISSING_OK : 0,
RangeVarCallbackForAlterRelation,
(void *) stmt);
}
/*
* AlterTable
* Execute ALTER TABLE, which can be a list of subcommands
*
* ALTER TABLE is performed in three phases:
* 1. Examine subcommands and perform pre-transformation checking.
* 2. Update system catalogs.
* 3. Scan table(s) to check new constraints, and optionally recopy
* the data into new table(s).
* Phase 3 is not performed unless one or more of the subcommands requires
* it. The intention of this design is to allow multiple independent
* updates of the table schema to be performed with only one pass over the
* data.
*
* ATPrepCmd performs phase 1. A "work queue" entry is created for
* each table to be affected (there may be multiple affected tables if the
* commands traverse a table inheritance hierarchy). Also we do preliminary
* validation of the subcommands, including parse transformation of those
* expressions that need to be evaluated with respect to the old table
* schema.
*
* ATRewriteCatalogs performs phase 2 for each affected table. (Note that
* phases 2 and 3 normally do no explicit recursion, since phase 1 already
* did it --- although some subcommands have to recurse in phase 2 instead.)
* Certain subcommands need to be performed before others to avoid
* unnecessary conflicts; for example, DROP COLUMN should come before
* ADD COLUMN. Therefore phase 1 divides the subcommands into multiple
* lists, one for each logical "pass" of phase 2.
*
* ATRewriteTables performs phase 3 for those tables that need it.
*
* Thanks to the magic of MVCC, an error anywhere along the way rolls back
* the whole operation; we don't have to do anything special to clean up.
*
* The caller must lock the relation, with an appropriate lock level
* for the subcommands requested, using AlterTableGetLockLevel(stmt->cmds)
* or higher. We pass the lock level down
* so that we can apply it recursively to inherited tables. Note that the
* lock level we want as we recurse might well be higher than required for
* that specific subcommand. So we pass down the overall lock requirement,
* rather than reassess it at lower levels.
*/
void
AlterTable(Oid relid, LOCKMODE lockmode, AlterTableStmt *stmt)
{
Relation rel;
/* Caller is required to provide an adequate lock. */
rel = relation_open(relid, NoLock);
CheckTableNotInUse(rel, "ALTER TABLE");
ATController(stmt, rel, stmt->cmds, stmt->relation->inh, lockmode);
}
/*
* AlterTableInternal
*
* ALTER TABLE with target specified by OID
*
* We do not reject if the relation is already open, because it's quite
* likely that one or more layers of caller have it open. That means it
* is unsafe to use this entry point for alterations that could break
* existing query plans. On the assumption it's not used for such, we
* don't have to reject pending AFTER triggers, either.
*/
void
AlterTableInternal(Oid relid, List *cmds, bool recurse)
{
Relation rel;
LOCKMODE lockmode = AlterTableGetLockLevel(cmds);
rel = relation_open(relid, lockmode);
EventTriggerAlterTableRelid(relid);
ATController(NULL, rel, cmds, recurse, lockmode);
}
/*
* AlterTableGetLockLevel
*
* Sets the overall lock level required for the supplied list of subcommands.
* Policy for doing this set according to needs of AlterTable(), see
* comments there for overall explanation.
*
* Function is called before and after parsing, so it must give same
* answer each time it is called. Some subcommands are transformed
* into other subcommand types, so the transform must never be made to a
* lower lock level than previously assigned. All transforms are noted below.
*
* Since this is called before we lock the table we cannot use table metadata
* to influence the type of lock we acquire.
*
* There should be no lockmodes hardcoded into the subcommand functions. All
* lockmode decisions for ALTER TABLE are made here only. The one exception is
* ALTER TABLE RENAME which is treated as a different statement type T_RenameStmt
* and does not travel through this section of code and cannot be combined with
* any of the subcommands given here.
*
* Note that Hot Standby only knows about AccessExclusiveLocks on the master
* so any changes that might affect SELECTs running on standbys need to use
* AccessExclusiveLocks even if you think a lesser lock would do, unless you
* have a solution for that also.
*
* Also note that pg_dump uses only an AccessShareLock, meaning that anything
* that takes a lock less than AccessExclusiveLock can change object definitions
* while pg_dump is running. Be careful to check that the appropriate data is
* derived by pg_dump using an MVCC snapshot, rather than syscache lookups,
* otherwise we might end up with an inconsistent dump that can't restore.
*/
LOCKMODE
AlterTableGetLockLevel(List *cmds)
{
/*
* This only works if we read catalog tables using MVCC snapshots.
*/
ListCell *lcmd;
LOCKMODE lockmode = ShareUpdateExclusiveLock;
foreach(lcmd, cmds)
{
AlterTableCmd *cmd = (AlterTableCmd *) lfirst(lcmd);
LOCKMODE cmd_lockmode = AccessExclusiveLock; /* default for compiler */
switch (cmd->subtype)
{
/*
* These subcommands rewrite the heap, so require full locks.
*/
case AT_AddColumn: /* may rewrite heap, in some cases and visible
* to SELECT */
case AT_SetTableSpace: /* must rewrite heap */
case AT_AlterColumnType: /* must rewrite heap */
cmd_lockmode = AccessExclusiveLock;
break;
/*
* These subcommands may require addition of toast tables. If
* we add a toast table to a table currently being scanned, we
* might miss data added to the new toast table by concurrent
* insert transactions.
*/
case AT_SetStorage: /* may add toast tables, see
* ATRewriteCatalogs() */
cmd_lockmode = AccessExclusiveLock;
break;
/*
* Removing constraints can affect SELECTs that have been
* optimized assuming the constraint holds true. See also
* CloneFkReferenced.
*/
case AT_DropConstraint: /* as DROP INDEX */
case AT_DropNotNull: /* may change some SQL plans */
cmd_lockmode = AccessExclusiveLock;
break;
/*
* Subcommands that may be visible to concurrent SELECTs
*/
case AT_DropColumn: /* change visible to SELECT */
case AT_AddColumnToView: /* CREATE VIEW */
case AT_DropOids: /* used to equiv to DropColumn */
case AT_EnableAlwaysRule: /* may change SELECT rules */
case AT_EnableReplicaRule: /* may change SELECT rules */
case AT_EnableRule: /* may change SELECT rules */
case AT_DisableRule: /* may change SELECT rules */
cmd_lockmode = AccessExclusiveLock;
break;
/*
* Changing owner may remove implicit SELECT privileges
*/
case AT_ChangeOwner: /* change visible to SELECT */
cmd_lockmode = AccessExclusiveLock;
break;
/*
* Changing foreign table options may affect optimization.
*/
case AT_GenericOptions:
case AT_AlterColumnGenericOptions:
cmd_lockmode = AccessExclusiveLock;
break;
/*
* These subcommands affect write operations only.
*/
case AT_EnableTrig:
case AT_EnableAlwaysTrig:
case AT_EnableReplicaTrig:
case AT_EnableTrigAll:
case AT_EnableTrigUser:
case AT_DisableTrig:
case AT_DisableTrigAll:
case AT_DisableTrigUser:
cmd_lockmode = ShareRowExclusiveLock;
break;
/*
* These subcommands affect write operations only. XXX
* Theoretically, these could be ShareRowExclusiveLock.
*/
case AT_ColumnDefault:
case AT_AlterConstraint:
case AT_AddIndex: /* from ADD CONSTRAINT */
case AT_AddIndexConstraint:
case AT_ReplicaIdentity:
case AT_SetNotNull:
case AT_EnableRowSecurity:
case AT_DisableRowSecurity:
case AT_ForceRowSecurity:
case AT_NoForceRowSecurity:
case AT_AddIdentity:
case AT_DropIdentity:
case AT_SetIdentity:
cmd_lockmode = AccessExclusiveLock;
break;
case AT_AddConstraint:
case AT_ProcessedConstraint: /* becomes AT_AddConstraint */
case AT_AddConstraintRecurse: /* becomes AT_AddConstraint */
case AT_ReAddConstraint: /* becomes AT_AddConstraint */
case AT_ReAddDomainConstraint: /* becomes AT_AddConstraint */
if (IsA(cmd->def, Constraint))
{
Constraint *con = (Constraint *) cmd->def;
switch (con->contype)
{
case CONSTR_EXCLUSION:
case CONSTR_PRIMARY:
case CONSTR_UNIQUE:
/*
* Cases essentially the same as CREATE INDEX. We
* could reduce the lock strength to ShareLock if
* we can work out how to allow concurrent catalog
* updates. XXX Might be set down to
* ShareRowExclusiveLock but requires further
* analysis.
*/
cmd_lockmode = AccessExclusiveLock;
break;
case CONSTR_FOREIGN:
/*
* We add triggers to both tables when we add a
* Foreign Key, so the lock level must be at least
* as strong as CREATE TRIGGER.
*/
cmd_lockmode = ShareRowExclusiveLock;
break;
default:
cmd_lockmode = AccessExclusiveLock;
}
}
break;
/*
* These subcommands affect inheritance behaviour. Queries
* started before us will continue to see the old inheritance
* behaviour, while queries started after we commit will see
* new behaviour. No need to prevent reads or writes to the
* subtable while we hook it up though. Changing the TupDesc
* may be a problem, so keep highest lock.
*/
case AT_AddInherit:
case AT_DropInherit:
cmd_lockmode = AccessExclusiveLock;
break;
/*
* These subcommands affect implicit row type conversion. They
* have affects similar to CREATE/DROP CAST on queries. don't
* provide for invalidating parse trees as a result of such
* changes, so we keep these at AccessExclusiveLock.
*/
case AT_AddOf:
case AT_DropOf:
cmd_lockmode = AccessExclusiveLock;
break;
/*
* Only used by CREATE OR REPLACE VIEW which must conflict
* with an SELECTs currently using the view.
*/
case AT_ReplaceRelOptions:
cmd_lockmode = AccessExclusiveLock;
break;
/*
* These subcommands affect general strategies for performance
* and maintenance, though don't change the semantic results
* from normal data reads and writes. Delaying an ALTER TABLE
* behind currently active writes only delays the point where
* the new strategy begins to take effect, so there is no
* benefit in waiting. In this case the minimum restriction
* applies: we don't currently allow concurrent catalog
* updates.
*/
case AT_SetStatistics: /* Uses MVCC in getTableAttrs() */
case AT_ClusterOn: /* Uses MVCC in getIndexes() */
case AT_DropCluster: /* Uses MVCC in getIndexes() */
case AT_SetOptions: /* Uses MVCC in getTableAttrs() */
case AT_ResetOptions: /* Uses MVCC in getTableAttrs() */
cmd_lockmode = ShareUpdateExclusiveLock;
break;
case AT_SetLogged:
case AT_SetUnLogged:
cmd_lockmode = AccessExclusiveLock;
break;
case AT_ValidateConstraint: /* Uses MVCC in getConstraints() */
cmd_lockmode = ShareUpdateExclusiveLock;
break;
/*
* Rel options are more complex than first appears. Options
* are set here for tables, views and indexes; for historical
* reasons these can all be used with ALTER TABLE, so we can't
* decide between them using the basic grammar.
*/
case AT_SetRelOptions: /* Uses MVCC in getIndexes() and
* getTables() */
case AT_ResetRelOptions: /* Uses MVCC in getIndexes() and
* getTables() */
cmd_lockmode = AlterTableGetRelOptionsLockLevel((List *) cmd->def);
break;
case AT_AttachPartition:
cmd_lockmode = ShareUpdateExclusiveLock;
break;
case AT_DetachPartition:
cmd_lockmode = AccessExclusiveLock;
break;
case AT_CheckNotNull:
/*
* This only examines the table's schema; but lock must be
* strong enough to prevent concurrent DROP NOT NULL.
*/
cmd_lockmode = AccessShareLock;
break;
default: /* oops */
elog(ERROR, "unrecognized alter table type: %d",
(int) cmd->subtype);
break;
}
/*
* Take the greatest lockmode from any subcommand
*/
if (cmd_lockmode > lockmode)
lockmode = cmd_lockmode;
}
return lockmode;
}
/*
* ATController provides top level control over the phases.
*
* parsetree is passed in to allow it to be passed to event triggers
* when requested.
*/
static void
ATController(AlterTableStmt *parsetree,
Relation rel, List *cmds, bool recurse, LOCKMODE lockmode)
{
List *wqueue = NIL;
ListCell *lcmd;
/* Phase 1: preliminary examination of commands, create work queue */
foreach(lcmd, cmds)
{
AlterTableCmd *cmd = (AlterTableCmd *) lfirst(lcmd);
ATPrepCmd(&wqueue, rel, cmd, recurse, false, lockmode);
}
/* Close the relation, but keep lock until commit */
relation_close(rel, NoLock);
/* Phase 2: update system catalogs */
ATRewriteCatalogs(&wqueue, lockmode);
/* Phase 3: scan/rewrite tables as needed */
ATRewriteTables(parsetree, &wqueue, lockmode);
}
/*
* ATPrepCmd
*
* Traffic cop for ALTER TABLE Phase 1 operations, including simple
* recursion and permission checks.
*
* Caller must have acquired appropriate lock type on relation already.
* This lock should be held until commit.
*/
static void
ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd,
bool recurse, bool recursing, LOCKMODE lockmode)
{
AlteredTableInfo *tab;
int pass = AT_PASS_UNSET;
/* Find or create work queue entry for this table */
tab = ATGetQueueEntry(wqueue, rel);
/*
* Copy the original subcommand for each table. This avoids conflicts
* when different child tables need to make different parse
* transformations (for example, the same column may have different column
* numbers in different children).
*/
cmd = copyObject(cmd);
/*
* Do permissions checking, recursion to child tables if needed, and any
* additional phase-1 processing needed.
*/
switch (cmd->subtype)
{
case AT_AddColumn: /* ADD COLUMN */
ATSimplePermissions(rel,
ATT_TABLE | ATT_COMPOSITE_TYPE | ATT_FOREIGN_TABLE);
ATPrepAddColumn(wqueue, rel, recurse, recursing, false, cmd,
lockmode);
/* Recursion occurs during execution phase */
pass = AT_PASS_ADD_COL;
break;
case AT_AddColumnToView: /* add column via CREATE OR REPLACE VIEW */
ATSimplePermissions(rel, ATT_VIEW);
ATPrepAddColumn(wqueue, rel, recurse, recursing, true, cmd,
lockmode);
/* Recursion occurs during execution phase */
pass = AT_PASS_ADD_COL;
break;
case AT_ColumnDefault: /* ALTER COLUMN DEFAULT */
/*
* We allow defaults on views so that INSERT into a view can have
* default-ish behavior. This works because the rewriter
* substitutes default values into INSERTs before it expands
* rules.
*/
ATSimplePermissions(rel, ATT_TABLE | ATT_VIEW | ATT_FOREIGN_TABLE);
ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode);
/* No command-specific prep needed */
pass = cmd->def ? AT_PASS_ADD_CONSTR : AT_PASS_DROP;
break;
case AT_AddIdentity:
ATSimplePermissions(rel, ATT_TABLE | ATT_VIEW | ATT_FOREIGN_TABLE);
/* This command never recurses */
pass = AT_PASS_ADD_CONSTR;
break;
case AT_SetIdentity:
ATSimplePermissions(rel, ATT_TABLE | ATT_VIEW | ATT_FOREIGN_TABLE);
/* This command never recurses */
pass = AT_PASS_COL_ATTRS;
break;
case AT_DropIdentity:
ATSimplePermissions(rel, ATT_TABLE | ATT_VIEW | ATT_FOREIGN_TABLE);
/* This command never recurses */
pass = AT_PASS_DROP;
break;
case AT_DropNotNull: /* ALTER COLUMN DROP NOT NULL */
ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
ATPrepDropNotNull(rel, recurse, recursing);
ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode);
pass = AT_PASS_DROP;
break;
case AT_SetNotNull: /* ALTER COLUMN SET NOT NULL */
ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
/* Need command-specific recursion decision */
ATPrepSetNotNull(wqueue, rel, cmd, recurse, recursing, lockmode);
pass = AT_PASS_COL_ATTRS;
break;
case AT_CheckNotNull: /* check column is already marked NOT NULL */
ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode);
/* No command-specific prep needed */
pass = AT_PASS_COL_ATTRS;
break;
case AT_SetStatistics: /* ALTER COLUMN SET STATISTICS */
ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode);
/* Performs own permission checks */
ATPrepSetStatistics(rel, cmd->name, cmd->num, cmd->def, lockmode);
pass = AT_PASS_MISC;
break;
case AT_SetOptions: /* ALTER COLUMN SET ( options ) */
case AT_ResetOptions: /* ALTER COLUMN RESET ( options ) */
ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW | ATT_INDEX | ATT_FOREIGN_TABLE);
/* This command never recurses */
pass = AT_PASS_MISC;
break;
case AT_SetStorage: /* ALTER COLUMN SET STORAGE */
ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW | ATT_FOREIGN_TABLE);
ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode);
/* No command-specific prep needed */
pass = AT_PASS_MISC;
break;
case AT_DropColumn: /* DROP COLUMN */
ATSimplePermissions(rel,
ATT_TABLE | ATT_COMPOSITE_TYPE | ATT_FOREIGN_TABLE);
ATPrepDropColumn(wqueue, rel, recurse, recursing, cmd, lockmode);
/* Recursion occurs during execution phase */
pass = AT_PASS_DROP;
break;
case AT_AddIndex: /* ADD INDEX */
ATSimplePermissions(rel, ATT_TABLE);
/* This command never recurses */
/* No command-specific prep needed */
pass = AT_PASS_ADD_INDEX;
break;
case AT_AddConstraint: /* ADD CONSTRAINT */
ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
/* Recursion occurs during execution phase */
/* No command-specific prep needed except saving recurse flag */
if (recurse)
cmd->subtype = AT_AddConstraintRecurse;
pass = AT_PASS_ADD_CONSTR;
break;
case AT_AddIndexConstraint: /* ADD CONSTRAINT USING INDEX */
ATSimplePermissions(rel, ATT_TABLE);
/* This command never recurses */
/* No command-specific prep needed */
pass = AT_PASS_ADD_CONSTR;
break;
case AT_DropConstraint: /* DROP CONSTRAINT */
ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
ATCheckPartitionsNotInUse(rel, lockmode);
/* Other recursion occurs during execution phase */
/* No command-specific prep needed except saving recurse flag */
if (recurse)
cmd->subtype = AT_DropConstraintRecurse;
pass = AT_PASS_DROP;
break;
case AT_AlterColumnType: /* ALTER COLUMN TYPE */
ATSimplePermissions(rel,
ATT_TABLE | ATT_COMPOSITE_TYPE | ATT_FOREIGN_TABLE);
/* Performs own recursion */
ATPrepAlterColumnType(wqueue, tab, rel, recurse, recursing, cmd, lockmode);
pass = AT_PASS_ALTER_TYPE;
break;
case AT_AlterColumnGenericOptions:
ATSimplePermissions(rel, ATT_FOREIGN_TABLE);
/* This command never recurses */
/* No command-specific prep needed */
pass = AT_PASS_MISC;
break;
case AT_ChangeOwner: /* ALTER OWNER */
/* This command never recurses */
/* No command-specific prep needed */
pass = AT_PASS_MISC;
break;
case AT_ClusterOn: /* CLUSTER ON */
case AT_DropCluster: /* SET WITHOUT CLUSTER */
ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW);
/* These commands never recurse */
/* No command-specific prep needed */
pass = AT_PASS_MISC;
break;
case AT_SetLogged: /* SET LOGGED */
ATSimplePermissions(rel, ATT_TABLE);
tab->chgPersistence = ATPrepChangePersistence(rel, true);
/* force rewrite if necessary; see comment in ATRewriteTables */
if (tab->chgPersistence)
{
tab->rewrite |= AT_REWRITE_ALTER_PERSISTENCE;
tab->newrelpersistence = RELPERSISTENCE_PERMANENT;
}
pass = AT_PASS_MISC;
break;
case AT_SetUnLogged: /* SET UNLOGGED */
ATSimplePermissions(rel, ATT_TABLE);
tab->chgPersistence = ATPrepChangePersistence(rel, false);
/* force rewrite if necessary; see comment in ATRewriteTables */
if (tab->chgPersistence)
{
tab->rewrite |= AT_REWRITE_ALTER_PERSISTENCE;
tab->newrelpersistence = RELPERSISTENCE_UNLOGGED;
}
pass = AT_PASS_MISC;
break;
case AT_DropOids: /* SET WITHOUT OIDS */
ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
pass = AT_PASS_DROP;
break;
case AT_SetTableSpace: /* SET TABLESPACE */
ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW | ATT_INDEX |
ATT_PARTITIONED_INDEX);
/* This command never recurses */
ATPrepSetTableSpace(tab, rel, cmd->name, lockmode);
pass = AT_PASS_MISC; /* doesn't actually matter */
break;
case AT_SetRelOptions: /* SET (...) */
case AT_ResetRelOptions: /* RESET (...) */
case AT_ReplaceRelOptions: /* reset them all, then set just these */
ATSimplePermissions(rel, ATT_TABLE | ATT_VIEW | ATT_MATVIEW | ATT_INDEX);
/* This command never recurses */
/* No command-specific prep needed */
pass = AT_PASS_MISC;
break;
case AT_AddInherit: /* INHERIT */
ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
/* This command never recurses */
ATPrepAddInherit(rel);
pass = AT_PASS_MISC;
break;
case AT_DropInherit: /* NO INHERIT */
ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
/* This command never recurses */
/* No command-specific prep needed */
pass = AT_PASS_MISC;
break;
case AT_AlterConstraint: /* ALTER CONSTRAINT */
ATSimplePermissions(rel, ATT_TABLE);
pass = AT_PASS_MISC;
break;
case AT_ValidateConstraint: /* VALIDATE CONSTRAINT */
ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
/* Recursion occurs during execution phase */
/* No command-specific prep needed except saving recurse flag */
if (recurse)
cmd->subtype = AT_ValidateConstraintRecurse;
pass = AT_PASS_MISC;
break;
case AT_ReplicaIdentity: /* REPLICA IDENTITY ... */
ATSimplePermissions(rel, ATT_TABLE | ATT_MATVIEW);
pass = AT_PASS_MISC;
/* This command never recurses */
/* No command-specific prep needed */
break;
case AT_EnableTrig: /* ENABLE TRIGGER variants */
case AT_EnableAlwaysTrig:
case AT_EnableReplicaTrig:
case AT_EnableTrigAll:
case AT_EnableTrigUser:
case AT_DisableTrig: /* DISABLE TRIGGER variants */
case AT_DisableTrigAll:
case AT_DisableTrigUser:
ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
pass = AT_PASS_MISC;
break;
case AT_EnableRule: /* ENABLE/DISABLE RULE variants */
case AT_EnableAlwaysRule:
case AT_EnableReplicaRule:
case AT_DisableRule:
case AT_AddOf: /* OF */
case AT_DropOf: /* NOT OF */
case AT_EnableRowSecurity:
case AT_DisableRowSecurity:
case AT_ForceRowSecurity:
case AT_NoForceRowSecurity:
ATSimplePermissions(rel, ATT_TABLE);
/* These commands never recurse */
/* No command-specific prep needed */
pass = AT_PASS_MISC;
break;
case AT_GenericOptions:
ATSimplePermissions(rel, ATT_FOREIGN_TABLE);
/* No command-specific prep needed */
pass = AT_PASS_MISC;
break;
case AT_AttachPartition:
ATSimplePermissions(rel, ATT_TABLE | ATT_PARTITIONED_INDEX);
/* No command-specific prep needed */
pass = AT_PASS_MISC;
break;
case AT_DetachPartition:
ATSimplePermissions(rel, ATT_TABLE);
/* No command-specific prep needed */
pass = AT_PASS_MISC;
break;
default: /* oops */
elog(ERROR, "unrecognized alter table type: %d",
(int) cmd->subtype);
pass = AT_PASS_UNSET; /* keep compiler quiet */
break;
}
Assert(pass > AT_PASS_UNSET);
/* Add the subcommand to the appropriate list for phase 2 */
tab->subcmds[pass] = lappend(tab->subcmds[pass], cmd);
}
/*
* ATRewriteCatalogs
*
* Traffic cop for ALTER TABLE Phase 2 operations. Subcommands are
* dispatched in a "safe" execution order (designed to avoid unnecessary
* conflicts).
*/
static void
ATRewriteCatalogs(List **wqueue, LOCKMODE lockmode)
{
int pass;
ListCell *ltab;
/*
* We process all the tables "in parallel", one pass at a time. This is
* needed because we may have to propagate work from one table to another
* (specifically, ALTER TYPE on a foreign key's PK has to dispatch the
* re-adding of the foreign key constraint to the other table). Work can
* only be propagated into later passes, however.
*/
for (pass = 0; pass < AT_NUM_PASSES; pass++)
{
/* Go through each table that needs to be processed */
foreach(ltab, *wqueue)
{
AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab);
List *subcmds = tab->subcmds[pass];
Relation rel;
ListCell *lcmd;
if (subcmds == NIL)
continue;
/*
* Appropriate lock was obtained by phase 1, needn't get it again
*/
rel = relation_open(tab->relid, NoLock);
foreach(lcmd, subcmds)
ATExecCmd(wqueue, tab, rel,
castNode(AlterTableCmd, lfirst(lcmd)),
lockmode);
/*
* After the ALTER TYPE pass, do cleanup work (this is not done in
* ATExecAlterColumnType since it should be done only once if
* multiple columns of a table are altered).
*/
if (pass == AT_PASS_ALTER_TYPE)
ATPostAlterTypeCleanup(wqueue, tab, lockmode);
relation_close(rel, NoLock);
}
}
/* Check to see if a toast table must be added. */
foreach(ltab, *wqueue)
{
AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab);
/*
* If the table is source table of ATTACH PARTITION command, we did
* not modify anything about it that will change its toasting
* requirement, so no need to check.
*/
if (((tab->relkind == RELKIND_RELATION ||
tab->relkind == RELKIND_PARTITIONED_TABLE) &&
tab->partition_constraint == NULL) ||
tab->relkind == RELKIND_MATVIEW)
AlterTableCreateToastTable(tab->relid, (Datum) 0, lockmode);
}
}
/*
* ATExecCmd: dispatch a subcommand to appropriate execution routine
*/
static void
ATExecCmd(List **wqueue, AlteredTableInfo *tab, Relation rel,
AlterTableCmd *cmd, LOCKMODE lockmode)
{
ObjectAddress address = InvalidObjectAddress;
switch (cmd->subtype)
{
case AT_AddColumn: /* ADD COLUMN */
case AT_AddColumnToView: /* add column via CREATE OR REPLACE VIEW */
address = ATExecAddColumn(wqueue, tab, rel, (ColumnDef *) cmd->def,
false, false,
cmd->missing_ok, lockmode);
break;
case AT_AddColumnRecurse:
address = ATExecAddColumn(wqueue, tab, rel, (ColumnDef *) cmd->def,
true, false,
cmd->missing_ok, lockmode);
break;
case AT_ColumnDefault: /* ALTER COLUMN DEFAULT */
address = ATExecColumnDefault(rel, cmd->name, cmd->def, lockmode);
break;
case AT_AddIdentity:
address = ATExecAddIdentity(rel, cmd->name, cmd->def, lockmode);
break;
case AT_SetIdentity:
address = ATExecSetIdentity(rel, cmd->name, cmd->def, lockmode);
break;
case AT_DropIdentity:
address = ATExecDropIdentity(rel, cmd->name, cmd->missing_ok, lockmode);
break;
case AT_DropNotNull: /* ALTER COLUMN DROP NOT NULL */
address = ATExecDropNotNull(rel, cmd->name, lockmode);
break;
case AT_SetNotNull: /* ALTER COLUMN SET NOT NULL */
address = ATExecSetNotNull(tab, rel, cmd->name, lockmode);
break;
case AT_CheckNotNull: /* check column is already marked NOT NULL */
ATExecCheckNotNull(tab, rel, cmd->name, lockmode);
break;
case AT_SetStatistics: /* ALTER COLUMN SET STATISTICS */
address = ATExecSetStatistics(rel, cmd->name, cmd->num, cmd->def, lockmode);
break;
case AT_SetOptions: /* ALTER COLUMN SET ( options ) */
address = ATExecSetOptions(rel, cmd->name, cmd->def, false, lockmode);
break;
case AT_ResetOptions: /* ALTER COLUMN RESET ( options ) */
address = ATExecSetOptions(rel, cmd->name, cmd->def, true, lockmode);
break;
case AT_SetStorage: /* ALTER COLUMN SET STORAGE */
address = ATExecSetStorage(rel, cmd->name, cmd->def, lockmode);
break;
case AT_DropColumn: /* DROP COLUMN */
address = ATExecDropColumn(wqueue, rel, cmd->name,
cmd->behavior, false, false,
cmd->missing_ok, lockmode,
NULL);
break;
case AT_DropColumnRecurse: /* DROP COLUMN with recursion */
address = ATExecDropColumn(wqueue, rel, cmd->name,
cmd->behavior, true, false,
cmd->missing_ok, lockmode,
NULL);
break;
case AT_AddIndex: /* ADD INDEX */
address = ATExecAddIndex(tab, rel, (IndexStmt *) cmd->def, false,
lockmode);
break;
case AT_ReAddIndex: /* ADD INDEX */
address = ATExecAddIndex(tab, rel, (IndexStmt *) cmd->def, true,
lockmode);
break;
case AT_AddConstraint: /* ADD CONSTRAINT */
address =
ATExecAddConstraint(wqueue, tab, rel, (Constraint *) cmd->def,
false, false, lockmode);
break;
case AT_AddConstraintRecurse: /* ADD CONSTRAINT with recursion */
address =
ATExecAddConstraint(wqueue, tab, rel, (Constraint *) cmd->def,
true, false, lockmode);
break;
case AT_ReAddConstraint: /* Re-add pre-existing check constraint */
address =
ATExecAddConstraint(wqueue, tab, rel, (Constraint *) cmd->def,
true, true, lockmode);
break;
case AT_ReAddDomainConstraint: /* Re-add pre-existing domain check
* constraint */
address =
AlterDomainAddConstraint(((AlterDomainStmt *) cmd->def)->typeName,
((AlterDomainStmt *) cmd->def)->def,
NULL);
break;
case AT_ReAddComment: /* Re-add existing comment */
address = CommentObject((CommentStmt *) cmd->def);
break;
case AT_AddIndexConstraint: /* ADD CONSTRAINT USING INDEX */
address = ATExecAddIndexConstraint(tab, rel, (IndexStmt *) cmd->def,
lockmode);
break;
case AT_AlterConstraint: /* ALTER CONSTRAINT */
address = ATExecAlterConstraint(rel, cmd, false, false, lockmode);
break;
case AT_ValidateConstraint: /* VALIDATE CONSTRAINT */
address = ATExecValidateConstraint(rel, cmd->name, false, false,
lockmode);
break;
case AT_ValidateConstraintRecurse: /* VALIDATE CONSTRAINT with
* recursion */
address = ATExecValidateConstraint(rel, cmd->name, true, false,
lockmode);
break;
case AT_DropConstraint: /* DROP CONSTRAINT */
ATExecDropConstraint(rel, cmd->name, cmd->behavior,
false, false,
cmd->missing_ok, lockmode);
break;
case AT_DropConstraintRecurse: /* DROP CONSTRAINT with recursion */
ATExecDropConstraint(rel, cmd->name, cmd->behavior,
true, false,
cmd->missing_ok, lockmode);
break;
case AT_AlterColumnType: /* ALTER COLUMN TYPE */
address = ATExecAlterColumnType(tab, rel, cmd, lockmode);
break;
case AT_AlterColumnGenericOptions: /* ALTER COLUMN OPTIONS */
address =
ATExecAlterColumnGenericOptions(rel, cmd->name,
(List *) cmd->def, lockmode);
break;
case AT_ChangeOwner: /* ALTER OWNER */
ATExecChangeOwner(RelationGetRelid(rel),
get_rolespec_oid(cmd->newowner, false),
false, lockmode);
break;
case AT_ClusterOn: /* CLUSTER ON */
address = ATExecClusterOn(rel, cmd->name, lockmode);
break;
case AT_DropCluster: /* SET WITHOUT CLUSTER */
ATExecDropCluster(rel, lockmode);
break;
case AT_SetLogged: /* SET LOGGED */
case AT_SetUnLogged: /* SET UNLOGGED */
break;
case AT_DropOids: /* SET WITHOUT OIDS */
/* nothing to do here, oid columns don't exist anymore */
break;
case AT_SetTableSpace: /* SET TABLESPACE */
/*
* Only do this for partitioned tables and indexes, for which this
* is just a catalog change. Other relation types which have
* storage are handled by Phase 3.
*/
if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE ||
rel->rd_rel->relkind == RELKIND_PARTITIONED_INDEX)
ATExecSetTableSpaceNoStorage(rel, tab->newTableSpace);
break;
case AT_SetRelOptions: /* SET (...) */
case AT_ResetRelOptions: /* RESET (...) */
case AT_ReplaceRelOptions: /* replace entire option list */
ATExecSetRelOptions(rel, (List *) cmd->def, cmd->subtype, lockmode);
break;
case AT_EnableTrig: /* ENABLE TRIGGER name */
ATExecEnableDisableTrigger(rel, cmd->name,
TRIGGER_FIRES_ON_ORIGIN, false, lockmode);
break;
case AT_EnableAlwaysTrig: /* ENABLE ALWAYS TRIGGER name */
ATExecEnableDisableTrigger(rel, cmd->name,
TRIGGER_FIRES_ALWAYS, false, lockmode);
break;
case AT_EnableReplicaTrig: /* ENABLE REPLICA TRIGGER name */
ATExecEnableDisableTrigger(rel, cmd->name,
TRIGGER_FIRES_ON_REPLICA, false, lockmode);
break;
case AT_DisableTrig: /* DISABLE TRIGGER name */
ATExecEnableDisableTrigger(rel, cmd->name,
TRIGGER_DISABLED, false, lockmode);
break;
case AT_EnableTrigAll: /* ENABLE TRIGGER ALL */
ATExecEnableDisableTrigger(rel, NULL,
TRIGGER_FIRES_ON_ORIGIN, false, lockmode);
break;
case AT_DisableTrigAll: /* DISABLE TRIGGER ALL */
ATExecEnableDisableTrigger(rel, NULL,
TRIGGER_DISABLED, false, lockmode);
break;
case AT_EnableTrigUser: /* ENABLE TRIGGER USER */
ATExecEnableDisableTrigger(rel, NULL,
TRIGGER_FIRES_ON_ORIGIN, true, lockmode);
break;
case AT_DisableTrigUser: /* DISABLE TRIGGER USER */
ATExecEnableDisableTrigger(rel, NULL,
TRIGGER_DISABLED, true, lockmode);
break;
case AT_EnableRule: /* ENABLE RULE name */
ATExecEnableDisableRule(rel, cmd->name,
RULE_FIRES_ON_ORIGIN, lockmode);
break;
case AT_EnableAlwaysRule: /* ENABLE ALWAYS RULE name */
ATExecEnableDisableRule(rel, cmd->name,
RULE_FIRES_ALWAYS, lockmode);
break;
case AT_EnableReplicaRule: /* ENABLE REPLICA RULE name */
ATExecEnableDisableRule(rel, cmd->name,
RULE_FIRES_ON_REPLICA, lockmode);
break;
case AT_DisableRule: /* DISABLE RULE name */
ATExecEnableDisableRule(rel, cmd->name,
RULE_DISABLED, lockmode);
break;
case AT_AddInherit:
address = ATExecAddInherit(rel, (RangeVar *) cmd->def, lockmode);
break;
case AT_DropInherit:
address = ATExecDropInherit(rel, (RangeVar *) cmd->def, lockmode);
break;
case AT_AddOf:
address = ATExecAddOf(rel, (TypeName *) cmd->def, lockmode);
break;
case AT_DropOf:
ATExecDropOf(rel, lockmode);
break;
case AT_ReplicaIdentity:
ATExecReplicaIdentity(rel, (ReplicaIdentityStmt *) cmd->def, lockmode);
break;
case AT_EnableRowSecurity:
ATExecEnableRowSecurity(rel);
break;
case AT_DisableRowSecurity:
ATExecDisableRowSecurity(rel);
break;
case AT_ForceRowSecurity:
ATExecForceNoForceRowSecurity(rel, true);
break;
case AT_NoForceRowSecurity:
ATExecForceNoForceRowSecurity(rel, false);
break;
case AT_GenericOptions:
ATExecGenericOptions(rel, (List *) cmd->def);
break;
case AT_AttachPartition:
if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
ATExecAttachPartition(wqueue, rel, (PartitionCmd *) cmd->def);
else
ATExecAttachPartitionIdx(wqueue, rel,
((PartitionCmd *) cmd->def)->name);
break;
case AT_DetachPartition:
/* ATPrepCmd ensures it must be a table */
Assert(rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE);
ATExecDetachPartition(rel, ((PartitionCmd *) cmd->def)->name);
break;
default: /* oops */
elog(ERROR, "unrecognized alter table type: %d",
(int) cmd->subtype);
break;
}
/*
* Report the subcommand to interested event triggers.
*/
EventTriggerCollectAlterTableSubcmd((Node *) cmd, address);
/*
* Bump the command counter to ensure the next subcommand in the sequence
* can see the changes so far
*/
CommandCounterIncrement();
}
/*
* ATRewriteTables: ALTER TABLE phase 3
*/
static void
ATRewriteTables(AlterTableStmt *parsetree, List **wqueue, LOCKMODE lockmode)
{
ListCell *ltab;
/* Go through each table that needs to be checked or rewritten */
foreach(ltab, *wqueue)
{
AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab);
/* Relations without storage may be ignored here */
if (!RELKIND_HAS_STORAGE(tab->relkind))
continue;
/*
* If we change column data types or add/remove OIDs, the operation
* has to be propagated to tables that use this table's rowtype as a
* column type. tab->newvals will also be non-NULL in the case where
* we're adding a column with a default. We choose to forbid that
* case as well, since composite types might eventually support
* defaults.
*
* (Eventually we'll probably need to check for composite type
* dependencies even when we're just scanning the table without a
* rewrite, but at the moment a composite type does not enforce any
* constraints, so it's not necessary/appropriate to enforce them just
* during ALTER.)
*/
if (tab->newvals != NIL || tab->rewrite > 0)
{
Relation rel;
rel = table_open(tab->relid, NoLock);
find_composite_type_dependencies(rel->rd_rel->reltype, rel, NULL);
table_close(rel, NoLock);
}
/*
* We only need to rewrite the table if at least one column needs to
* be recomputed, we are adding/removing the OID column, or we are
* changing its persistence.
*
* There are two reasons for requiring a rewrite when changing
* persistence: on one hand, we need to ensure that the buffers
* belonging to each of the two relations are marked with or without
* BM_PERMANENT properly. On the other hand, since rewriting creates
* and assigns a new relfilenode, we automatically create or drop an
* init fork for the relation as appropriate.
*/
if (tab->rewrite > 0)
{
/* Build a temporary relation and copy data */
Relation OldHeap;
Oid OIDNewHeap;
Oid NewTableSpace;
char persistence;
OldHeap = table_open(tab->relid, NoLock);
/*
* We don't support rewriting of system catalogs; there are too
* many corner cases and too little benefit. In particular this
* is certainly not going to work for mapped catalogs.
*/
if (IsSystemRelation(OldHeap))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot rewrite system relation \"%s\"",
RelationGetRelationName(OldHeap))));
if (RelationIsUsedAsCatalogTable(OldHeap))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot rewrite table \"%s\" used as a catalog table",
RelationGetRelationName(OldHeap))));
/*
* Don't allow rewrite on temp tables of other backends ... their
* local buffer manager is not going to cope.
*/
if (RELATION_IS_OTHER_TEMP(OldHeap))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot rewrite temporary tables of other sessions")));
/*
* Select destination tablespace (same as original unless user
* requested a change)
*/
if (tab->newTableSpace)
NewTableSpace = tab->newTableSpace;
else
NewTableSpace = OldHeap->rd_rel->reltablespace;
/*
* Select persistence of transient table (same as original unless
* user requested a change)
*/
persistence = tab->chgPersistence ?
tab->newrelpersistence : OldHeap->rd_rel->relpersistence;
table_close(OldHeap, NoLock);
/*
* Fire off an Event Trigger now, before actually rewriting the
* table.
*
* We don't support Event Trigger for nested commands anywhere,
* here included, and parsetree is given NULL when coming from
* AlterTableInternal.
*
* And fire it only once.
*/
if (parsetree)
EventTriggerTableRewrite((Node *) parsetree,
tab->relid,
tab->rewrite);
/*
* Create transient table that will receive the modified data.
*
* Ensure it is marked correctly as logged or unlogged. We have
* to do this here so that buffers for the new relfilenode will
* have the right persistence set, and at the same time ensure
* that the original filenode's buffers will get read in with the
* correct setting (i.e. the original one). Otherwise a rollback
* after the rewrite would possibly result with buffers for the
* original filenode having the wrong persistence setting.
*
* NB: This relies on swap_relation_files() also swapping the
* persistence. That wouldn't work for pg_class, but that can't be
* unlogged anyway.
*/
OIDNewHeap = make_new_heap(tab->relid, NewTableSpace, persistence,
lockmode);
/*
* Copy the heap data into the new table with the desired
* modifications, and test the current data within the table
* against new constraints generated by ALTER TABLE commands.
*/
ATRewriteTable(tab, OIDNewHeap, lockmode);
/*
* Swap the physical files of the old and new heaps, then rebuild
* indexes and discard the old heap. We can use RecentXmin for
* the table's new relfrozenxid because we rewrote all the tuples
* in ATRewriteTable, so no older Xid remains in the table. Also,
* we never try to swap toast tables by content, since we have no
* interest in letting this code work on system catalogs.
*/
finish_heap_swap(tab->relid, OIDNewHeap,
false, false, true,
!OidIsValid(tab->newTableSpace),
RecentXmin,
ReadNextMultiXactId(),
persistence);
}
else
{
/*
* If required, test the current data within the table against new
* constraints generated by ALTER TABLE commands, but don't
* rebuild data.
*/
if (tab->constraints != NIL || tab->verify_new_notnull ||
tab->partition_constraint != NULL)
ATRewriteTable(tab, InvalidOid, lockmode);
/*
* If we had SET TABLESPACE but no reason to reconstruct tuples,
* just do a block-by-block copy.
*/
if (tab->newTableSpace)
ATExecSetTableSpace(tab->relid, tab->newTableSpace, lockmode);
}
}
/*
* Foreign key constraints are checked in a final pass, since (a) it's
* generally best to examine each one separately, and (b) it's at least
* theoretically possible that we have changed both relations of the
* foreign key, and we'd better have finished both rewrites before we try
* to read the tables.
*/
foreach(ltab, *wqueue)
{
AlteredTableInfo *tab = (AlteredTableInfo *) lfirst(ltab);
Relation rel = NULL;
ListCell *lcon;
/* Relations without storage may be ignored here too */
if (!RELKIND_HAS_STORAGE(tab->relkind))
continue;
foreach(lcon, tab->constraints)
{
NewConstraint *con = lfirst(lcon);
if (con->contype == CONSTR_FOREIGN)
{
Constraint *fkconstraint = (Constraint *) con->qual;
Relation refrel;
if (rel == NULL)
{
/* Long since locked, no need for another */
rel = table_open(tab->relid, NoLock);
}
refrel = table_open(con->refrelid, RowShareLock);
validateForeignKeyConstraint(fkconstraint->conname, rel, refrel,
con->refindid,
con->conid);
/*
* No need to mark the constraint row as validated, we did
* that when we inserted the row earlier.
*/
table_close(refrel, NoLock);
}
}
if (rel)
table_close(rel, NoLock);
}
}
/*
* ATRewriteTable: scan or rewrite one table
*
* OIDNewHeap is InvalidOid if we don't need to rewrite
*/
static void
ATRewriteTable(AlteredTableInfo *tab, Oid OIDNewHeap, LOCKMODE lockmode)
{
Relation oldrel;
Relation newrel;
TupleDesc oldTupDesc;
TupleDesc newTupDesc;
bool needscan = false;
List *notnull_attrs;
int i;
ListCell *l;
EState *estate;
CommandId mycid;
BulkInsertState bistate;
int ti_options;
ExprState *partqualstate = NULL;
/*
* Open the relation(s). We have surely already locked the existing
* table.
*/
oldrel = table_open(tab->relid, NoLock);
oldTupDesc = tab->oldDesc;
newTupDesc = RelationGetDescr(oldrel); /* includes all mods */
if (OidIsValid(OIDNewHeap))
newrel = table_open(OIDNewHeap, lockmode);
else
newrel = NULL;
/*
* Prepare a BulkInsertState and options for table_tuple_insert. Because
* we're building a new heap, we can skip WAL-logging and fsync it to disk
* at the end instead (unless WAL-logging is required for archiving or
* streaming replication). The FSM is empty too, so don't bother using it.
*/
if (newrel)
{
mycid = GetCurrentCommandId(true);
bistate = GetBulkInsertState();
ti_options = TABLE_INSERT_SKIP_FSM;
if (!XLogIsNeeded())
ti_options |= TABLE_INSERT_SKIP_WAL;
}
else
{
/* keep compiler quiet about using these uninitialized */
mycid = 0;
bistate = NULL;
ti_options = 0;
}
/*
* Generate the constraint and default execution states
*/
estate = CreateExecutorState();
/* Build the needed expression execution states */
foreach(l, tab->constraints)
{
NewConstraint *con = lfirst(l);
switch (con->contype)
{
case CONSTR_CHECK:
needscan = true;
con->qualstate = ExecPrepareExpr((Expr *) con->qual, estate);
break;
case CONSTR_FOREIGN:
/* Nothing to do here */
break;
default:
elog(ERROR, "unrecognized constraint type: %d",
(int) con->contype);
}
}
/* Build expression execution states for partition check quals */
if (tab->partition_constraint)
{
needscan = true;
partqualstate = ExecPrepareExpr(tab->partition_constraint, estate);
}
foreach(l, tab->newvals)
{
NewColumnValue *ex = lfirst(l);
/* expr already planned */
ex->exprstate = ExecInitExpr((Expr *) ex->expr, NULL);
}
notnull_attrs = NIL;
if (newrel || tab->verify_new_notnull)
{
/*
* If we are rebuilding the tuples OR if we added any new but not
* verified NOT NULL constraints, check all not-null constraints. This
* is a bit of overkill but it minimizes risk of bugs, and
* heap_attisnull is a pretty cheap test anyway.
*/
for (i = 0; i < newTupDesc->natts; i++)
{
Form_pg_attribute attr = TupleDescAttr(newTupDesc, i);
if (attr->attnotnull && !attr->attisdropped)
notnull_attrs = lappend_int(notnull_attrs, i);
}
if (notnull_attrs)
needscan = true;
}
if (newrel || needscan)
{
ExprContext *econtext;
TupleTableSlot *oldslot;
TupleTableSlot *newslot;
TableScanDesc scan;
MemoryContext oldCxt;
List *dropped_attrs = NIL;
ListCell *lc;
Snapshot snapshot;
if (newrel)
ereport(DEBUG1,
(errmsg("rewriting table \"%s\"",
RelationGetRelationName(oldrel))));
else
ereport(DEBUG1,
(errmsg("verifying table \"%s\"",
RelationGetRelationName(oldrel))));
if (newrel)
{
/*
* All predicate locks on the tuples or pages are about to be made
* invalid, because we move tuples around. Promote them to
* relation locks.
*/
TransferPredicateLocksToHeapRelation(oldrel);
}
econtext = GetPerTupleExprContext(estate);
/*
* Create necessary tuple slots. When rewriting, two slots are needed,
* otherwise one suffices. In the case where one slot suffices, we
* need to use the new tuple descriptor, otherwise some constraints
* can't be evaluated. Note that even when the tuple layout is the
* same and no rewrite is required, the tupDescs might not be
* (consider ADD COLUMN without a default).
*/
if (tab->rewrite)
{
Assert(newrel != NULL);
oldslot = MakeSingleTupleTableSlot(oldTupDesc,
table_slot_callbacks(oldrel));
newslot = MakeSingleTupleTableSlot(newTupDesc,
table_slot_callbacks(newrel));
/*
* Set all columns in the new slot to NULL initially, to ensure
* columns added as part of the rewrite are initialized to
* NULL. That is necessary as tab->newvals will not contain an
* expression for columns with a NULL default, e.g. when adding a
* column without a default together with a column with a default
* requiring an actual rewrite.
*/
ExecStoreAllNullTuple(newslot);
}
else
{
oldslot = MakeSingleTupleTableSlot(newTupDesc,
table_slot_callbacks(oldrel));
newslot = NULL;
}
/*
* Any attributes that are dropped according to the new tuple
* descriptor can be set to NULL. We precompute the list of dropped
* attributes to avoid needing to do so in the per-tuple loop.
*/
for (i = 0; i < newTupDesc->natts; i++)
{
if (TupleDescAttr(newTupDesc, i)->attisdropped)
dropped_attrs = lappend_int(dropped_attrs, i);
}
/*
* Scan through the rows, generating a new row if needed and then
* checking all the constraints.
*/
snapshot = RegisterSnapshot(GetLatestSnapshot());
scan = table_beginscan(oldrel, snapshot, 0, NULL);
/*
* Switch to per-tuple memory context and reset it for each tuple
* produced, so we don't leak memory.
*/
oldCxt = MemoryContextSwitchTo(GetPerTupleMemoryContext(estate));
while (table_scan_getnextslot(scan, ForwardScanDirection, oldslot))
{
TupleTableSlot *insertslot;
if (tab->rewrite > 0)
{
/* Extract data from old tuple */
slot_getallattrs(oldslot);
ExecClearTuple(newslot);
/* copy attributes */
memcpy(newslot->tts_values, oldslot->tts_values,
sizeof(Datum) * oldslot->tts_nvalid);
memcpy(newslot->tts_isnull, oldslot->tts_isnull,
sizeof(bool) * oldslot->tts_nvalid);
/* Set dropped attributes to null in new tuple */
foreach(lc, dropped_attrs)
newslot->tts_isnull[lfirst_int(lc)] = true;
/*
* Process supplied expressions to replace selected columns.
* Expression inputs come from the old tuple.
*/
econtext->ecxt_scantuple = oldslot;
foreach(l, tab->newvals)
{
NewColumnValue *ex = lfirst(l);
newslot->tts_values[ex->attnum - 1]
= ExecEvalExpr(ex->exprstate,
econtext,
&newslot->tts_isnull[ex->attnum - 1]);
}
ExecStoreVirtualTuple(newslot);
/*
* Constraints might reference the tableoid column, so
* initialize t_tableOid before evaluating them.
*/
newslot->tts_tableOid = RelationGetRelid(oldrel);
insertslot = newslot;
}
else
{
/*
* If there's no rewrite, old and new table are guaranteed to
* have the same AM, so we can just use the old slot to verify
* new constraints etc.
*/
insertslot = oldslot;
}
/* Now check any constraints on the possibly-changed tuple */
econtext->ecxt_scantuple = insertslot;
foreach(l, notnull_attrs)
{
int attn = lfirst_int(l);
if (slot_attisnull(insertslot, attn + 1))
{
Form_pg_attribute attr = TupleDescAttr(newTupDesc, attn);
ereport(ERROR,
(errcode(ERRCODE_NOT_NULL_VIOLATION),
errmsg("column \"%s\" contains null values",
NameStr(attr->attname)),
errtablecol(oldrel, attn + 1)));
}
}
foreach(l, tab->constraints)
{
NewConstraint *con = lfirst(l);
switch (con->contype)
{
case CONSTR_CHECK:
if (!ExecCheck(con->qualstate, econtext))
ereport(ERROR,
(errcode(ERRCODE_CHECK_VIOLATION),
errmsg("check constraint \"%s\" is violated by some row",
con->name),
errtableconstraint(oldrel, con->name)));
break;
case CONSTR_FOREIGN:
/* Nothing to do here */
break;
default:
elog(ERROR, "unrecognized constraint type: %d",
(int) con->contype);
}
}
if (partqualstate && !ExecCheck(partqualstate, econtext))
{
if (tab->validate_default)
ereport(ERROR,
(errcode(ERRCODE_CHECK_VIOLATION),
errmsg("updated partition constraint for default partition would be violated by some row")));
else
ereport(ERROR,
(errcode(ERRCODE_CHECK_VIOLATION),
errmsg("partition constraint is violated by some row")));
}
/* Write the tuple out to the new relation */
if (newrel)
table_tuple_insert(newrel, insertslot, mycid,
ti_options, bistate);
ResetExprContext(econtext);
CHECK_FOR_INTERRUPTS();
}
MemoryContextSwitchTo(oldCxt);
table_endscan(scan);
UnregisterSnapshot(snapshot);
ExecDropSingleTupleTableSlot(oldslot);
if (newslot)
ExecDropSingleTupleTableSlot(newslot);
}
FreeExecutorState(estate);
table_close(oldrel, NoLock);
if (newrel)
{
FreeBulkInsertState(bistate);
table_finish_bulk_insert(newrel, ti_options);
table_close(newrel, NoLock);
}
}
/*
* ATGetQueueEntry: find or create an entry in the ALTER TABLE work queue
*/
static AlteredTableInfo *
ATGetQueueEntry(List **wqueue, Relation rel)
{
Oid relid = RelationGetRelid(rel);
AlteredTableInfo *tab;
ListCell *ltab;
foreach(ltab, *wqueue)
{
tab = (AlteredTableInfo *) lfirst(ltab);
if (tab->relid == relid)
return tab;
}
/*
* Not there, so add it. Note that we make a copy of the relation's
* existing descriptor before anything interesting can happen to it.
*/
tab = (AlteredTableInfo *) palloc0(sizeof(AlteredTableInfo));
tab->relid = relid;
tab->relkind = rel->rd_rel->relkind;
tab->oldDesc = CreateTupleDescCopyConstr(RelationGetDescr(rel));
tab->newrelpersistence = RELPERSISTENCE_PERMANENT;
tab->chgPersistence = false;
*wqueue = lappend(*wqueue, tab);
return tab;
}
/*
* ATSimplePermissions
*
* - Ensure that it is a relation (or possibly a view)
* - Ensure this user is the owner
* - Ensure that it is not a system table
*/
static void
ATSimplePermissions(Relation rel, int allowed_targets)
{
int actual_target;
switch (rel->rd_rel->relkind)
{
case RELKIND_RELATION:
case RELKIND_PARTITIONED_TABLE:
actual_target = ATT_TABLE;
break;
case RELKIND_VIEW:
actual_target = ATT_VIEW;
break;
case RELKIND_MATVIEW:
actual_target = ATT_MATVIEW;
break;
case RELKIND_INDEX:
actual_target = ATT_INDEX;
break;
case RELKIND_PARTITIONED_INDEX:
actual_target = ATT_PARTITIONED_INDEX;
break;
case RELKIND_COMPOSITE_TYPE:
actual_target = ATT_COMPOSITE_TYPE;
break;
case RELKIND_FOREIGN_TABLE:
actual_target = ATT_FOREIGN_TABLE;
break;
default:
actual_target = 0;
break;
}
/* Wrong target type? */
if ((actual_target & allowed_targets) == 0)
ATWrongRelkindError(rel, allowed_targets);
/* Permissions checks */
if (!pg_class_ownercheck(RelationGetRelid(rel), GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(rel->rd_rel->relkind),
RelationGetRelationName(rel));
if (!allowSystemTableMods && IsSystemRelation(rel))
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("permission denied: \"%s\" is a system catalog",
RelationGetRelationName(rel))));
}
/*
* ATWrongRelkindError
*
* Throw an error when a relation has been determined to be of the wrong
* type.
*/
static void
ATWrongRelkindError(Relation rel, int allowed_targets)
{
char *msg;
switch (allowed_targets)
{
case ATT_TABLE:
msg = _("\"%s\" is not a table");
break;
case ATT_TABLE | ATT_VIEW:
msg = _("\"%s\" is not a table or view");
break;
case ATT_TABLE | ATT_VIEW | ATT_FOREIGN_TABLE:
msg = _("\"%s\" is not a table, view, or foreign table");
break;
case ATT_TABLE | ATT_VIEW | ATT_MATVIEW | ATT_INDEX:
msg = _("\"%s\" is not a table, view, materialized view, or index");
break;
case ATT_TABLE | ATT_MATVIEW:
msg = _("\"%s\" is not a table or materialized view");
break;
case ATT_TABLE | ATT_MATVIEW | ATT_INDEX:
msg = _("\"%s\" is not a table, materialized view, or index");
break;
case ATT_TABLE | ATT_MATVIEW | ATT_FOREIGN_TABLE:
msg = _("\"%s\" is not a table, materialized view, or foreign table");
break;
case ATT_TABLE | ATT_FOREIGN_TABLE:
msg = _("\"%s\" is not a table or foreign table");
break;
case ATT_TABLE | ATT_COMPOSITE_TYPE | ATT_FOREIGN_TABLE:
msg = _("\"%s\" is not a table, composite type, or foreign table");
break;
case ATT_TABLE | ATT_MATVIEW | ATT_INDEX | ATT_FOREIGN_TABLE:
msg = _("\"%s\" is not a table, materialized view, index, or foreign table");
break;
case ATT_VIEW:
msg = _("\"%s\" is not a view");
break;
case ATT_FOREIGN_TABLE:
msg = _("\"%s\" is not a foreign table");
break;
default:
/* shouldn't get here, add all necessary cases above */
msg = _("\"%s\" is of the wrong type");
break;
}
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg(msg, RelationGetRelationName(rel))));
}
/*
* ATSimpleRecursion
*
* Simple table recursion sufficient for most ALTER TABLE operations.
* All direct and indirect children are processed in an unspecified order.
* Note that if a child inherits from the original table via multiple
* inheritance paths, it will be visited just once.
*/
static void
ATSimpleRecursion(List **wqueue, Relation rel,
AlterTableCmd *cmd, bool recurse, LOCKMODE lockmode)
{
/*
* Propagate to children if desired. Only plain tables, foreign tables
* and partitioned tables have children, so no need to search for other
* relkinds.
*/
if (recurse &&
(rel->rd_rel->relkind == RELKIND_RELATION ||
rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE ||
rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE))
{
Oid relid = RelationGetRelid(rel);
ListCell *child;
List *children;
children = find_all_inheritors(relid, lockmode, NULL);
/*
* find_all_inheritors does the recursive search of the inheritance
* hierarchy, so all we have to do is process all of the relids in the
* list that it returns.
*/
foreach(child, children)
{
Oid childrelid = lfirst_oid(child);
Relation childrel;
if (childrelid == relid)
continue;
/* find_all_inheritors already got lock */
childrel = relation_open(childrelid, NoLock);
CheckTableNotInUse(childrel, "ALTER TABLE");
ATPrepCmd(wqueue, childrel, cmd, false, true, lockmode);
relation_close(childrel, NoLock);
}
}
}
/*
* Obtain list of partitions of the given table, locking them all at the given
* lockmode and ensuring that they all pass CheckTableNotInUse.
*
* This function is a no-op if the given relation is not a partitioned table;
* in particular, nothing is done if it's a legacy inheritance parent.
*/
static void
ATCheckPartitionsNotInUse(Relation rel, LOCKMODE lockmode)
{
if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
{
List *inh;
ListCell *cell;
inh = find_all_inheritors(RelationGetRelid(rel), lockmode, NULL);
/* first element is the parent rel; must ignore it */
for_each_cell(cell, inh, list_second_cell(inh))
{
Relation childrel;
/* find_all_inheritors already got lock */
childrel = table_open(lfirst_oid(cell), NoLock);
CheckTableNotInUse(childrel, "ALTER TABLE");
table_close(childrel, NoLock);
}
list_free(inh);
}
}
/*
* ATTypedTableRecursion
*
* Propagate ALTER TYPE operations to the typed tables of that type.
* Also check the RESTRICT/CASCADE behavior. Given CASCADE, also permit
* recursion to inheritance children of the typed tables.
*/
static void
ATTypedTableRecursion(List **wqueue, Relation rel, AlterTableCmd *cmd,
LOCKMODE lockmode)
{
ListCell *child;
List *children;
Assert(rel->rd_rel->relkind == RELKIND_COMPOSITE_TYPE);
children = find_typed_table_dependencies(rel->rd_rel->reltype,
RelationGetRelationName(rel),
cmd->behavior);
foreach(child, children)
{
Oid childrelid = lfirst_oid(child);
Relation childrel;
childrel = relation_open(childrelid, lockmode);
CheckTableNotInUse(childrel, "ALTER TABLE");
ATPrepCmd(wqueue, childrel, cmd, true, true, lockmode);
relation_close(childrel, NoLock);
}
}
/*
* find_composite_type_dependencies
*
* Check to see if the type "typeOid" is being used as a column in some table
* (possibly nested several levels deep in composite types, arrays, etc!).
* Eventually, we'd like to propagate the check or rewrite operation
* into such tables, but for now, just error out if we find any.
*
* Caller should provide either the associated relation of a rowtype,
* or a type name (not both) for use in the error message, if any.
*
* Note that "typeOid" is not necessarily a composite type; it could also be
* another container type such as an array or range, or a domain over one of
* these things. The name of this function is therefore somewhat historical,
* but it's not worth changing.
*
* We assume that functions and views depending on the type are not reasons
* to reject the ALTER. (How safe is this really?)
*/
void
find_composite_type_dependencies(Oid typeOid, Relation origRelation,
const char *origTypeName)
{
Relation depRel;
ScanKeyData key[2];
SysScanDesc depScan;
HeapTuple depTup;
/* since this function recurses, it could be driven to stack overflow */
check_stack_depth();
/*
* We scan pg_depend to find those things that depend on the given type.
* (We assume we can ignore refobjsubid for a type.)
*/
depRel = table_open(DependRelationId, AccessShareLock);
ScanKeyInit(&key[0],
Anum_pg_depend_refclassid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(TypeRelationId));
ScanKeyInit(&key[1],
Anum_pg_depend_refobjid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(typeOid));
depScan = systable_beginscan(depRel, DependReferenceIndexId, true,
NULL, 2, key);
while (HeapTupleIsValid(depTup = systable_getnext(depScan)))
{
Form_pg_depend pg_depend = (Form_pg_depend) GETSTRUCT(depTup);
Relation rel;
Form_pg_attribute att;
/* Check for directly dependent types */
if (pg_depend->classid == TypeRelationId)
{
/*
* This must be an array, domain, or range containing the given
* type, so recursively check for uses of this type. Note that
* any error message will mention the original type not the
* container; this is intentional.
*/
find_composite_type_dependencies(pg_depend->objid,
origRelation, origTypeName);
continue;
}
/* Else, ignore dependees that aren't user columns of relations */
/* (we assume system columns are never of interesting types) */
if (pg_depend->classid != RelationRelationId ||
pg_depend->objsubid <= 0)
continue;
rel = relation_open(pg_depend->objid, AccessShareLock);
att = TupleDescAttr(rel->rd_att, pg_depend->objsubid - 1);
if (rel->rd_rel->relkind == RELKIND_RELATION ||
rel->rd_rel->relkind == RELKIND_MATVIEW ||
rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
{
if (origTypeName)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter type \"%s\" because column \"%s.%s\" uses it",
origTypeName,
RelationGetRelationName(rel),
NameStr(att->attname))));
else if (origRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter type \"%s\" because column \"%s.%s\" uses it",
RelationGetRelationName(origRelation),
RelationGetRelationName(rel),
NameStr(att->attname))));
else if (origRelation->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter foreign table \"%s\" because column \"%s.%s\" uses its row type",
RelationGetRelationName(origRelation),
RelationGetRelationName(rel),
NameStr(att->attname))));
else
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter table \"%s\" because column \"%s.%s\" uses its row type",
RelationGetRelationName(origRelation),
RelationGetRelationName(rel),
NameStr(att->attname))));
}
else if (OidIsValid(rel->rd_rel->reltype))
{
/*
* A view or composite type itself isn't a problem, but we must
* recursively check for indirect dependencies via its rowtype.
*/
find_composite_type_dependencies(rel->rd_rel->reltype,
origRelation, origTypeName);
}
relation_close(rel, AccessShareLock);
}
systable_endscan(depScan);
relation_close(depRel, AccessShareLock);
}
/*
* find_typed_table_dependencies
*
* Check to see if a composite type is being used as the type of a
* typed table. Abort if any are found and behavior is RESTRICT.
* Else return the list of tables.
*/
static List *
find_typed_table_dependencies(Oid typeOid, const char *typeName, DropBehavior behavior)
{
Relation classRel;
ScanKeyData key[1];
TableScanDesc scan;
HeapTuple tuple;
List *result = NIL;
classRel = table_open(RelationRelationId, AccessShareLock);
ScanKeyInit(&key[0],
Anum_pg_class_reloftype,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(typeOid));
scan = table_beginscan_catalog(classRel, 1, key);
while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
{
Form_pg_class classform = (Form_pg_class) GETSTRUCT(tuple);
if (behavior == DROP_RESTRICT)
ereport(ERROR,
(errcode(ERRCODE_DEPENDENT_OBJECTS_STILL_EXIST),
errmsg("cannot alter type \"%s\" because it is the type of a typed table",
typeName),
errhint("Use ALTER ... CASCADE to alter the typed tables too.")));
else
result = lappend_oid(result, classform->oid);
}
table_endscan(scan);
table_close(classRel, AccessShareLock);
return result;
}
/*
* check_of_type
*
* Check whether a type is suitable for CREATE TABLE OF/ALTER TABLE OF. If it
* isn't suitable, throw an error. Currently, we require that the type
* originated with CREATE TYPE AS. We could support any row type, but doing so
* would require handling a number of extra corner cases in the DDL commands.
* (Also, allowing domain-over-composite would open up a can of worms about
* whether and how the domain's constraints should apply to derived tables.)
*/
void
check_of_type(HeapTuple typetuple)
{
Form_pg_type typ = (Form_pg_type) GETSTRUCT(typetuple);
bool typeOk = false;
if (typ->typtype == TYPTYPE_COMPOSITE)
{
Relation typeRelation;
Assert(OidIsValid(typ->typrelid));
typeRelation = relation_open(typ->typrelid, AccessShareLock);
typeOk = (typeRelation->rd_rel->relkind == RELKIND_COMPOSITE_TYPE);
/*
* Close the parent rel, but keep our AccessShareLock on it until xact
* commit. That will prevent someone else from deleting or ALTERing
* the type before the typed table creation/conversion commits.
*/
relation_close(typeRelation, NoLock);
}
if (!typeOk)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("type %s is not a composite type",
format_type_be(typ->oid))));
}
/*
* ALTER TABLE ADD COLUMN
*
* Adds an additional attribute to a relation making the assumption that
* CHECK, NOT NULL, and FOREIGN KEY constraints will be removed from the
* AT_AddColumn AlterTableCmd by parse_utilcmd.c and added as independent
* AlterTableCmd's.
*
* ADD COLUMN cannot use the normal ALTER TABLE recursion mechanism, because we
* have to decide at runtime whether to recurse or not depending on whether we
* actually add a column or merely merge with an existing column. (We can't
* check this in a static pre-pass because it won't handle multiple inheritance
* situations correctly.)
*/
static void
ATPrepAddColumn(List **wqueue, Relation rel, bool recurse, bool recursing,
bool is_view, AlterTableCmd *cmd, LOCKMODE lockmode)
{
if (rel->rd_rel->reloftype && !recursing)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot add column to typed table")));
if (rel->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
ATTypedTableRecursion(wqueue, rel, cmd, lockmode);
if (recurse && !is_view)
cmd->subtype = AT_AddColumnRecurse;
}
/*
* Add a column to a table. The return value is the address of the
* new column in the parent relation.
*/
static ObjectAddress
ATExecAddColumn(List **wqueue, AlteredTableInfo *tab, Relation rel,
ColumnDef *colDef,
bool recurse, bool recursing,
bool if_not_exists, LOCKMODE lockmode)
{
Oid myrelid = RelationGetRelid(rel);
Relation pgclass,
attrdesc;
HeapTuple reltup;
FormData_pg_attribute attribute;
int newattnum;
char relkind;
HeapTuple typeTuple;
Oid typeOid;
int32 typmod;
Oid collOid;
Form_pg_type tform;
Expr *defval;
List *children;
ListCell *child;
AclResult aclresult;
ObjectAddress address;
/* At top level, permission check was done in ATPrepCmd, else do it */
if (recursing)
ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
if (rel->rd_rel->relispartition && !recursing)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot add column to a partition")));
attrdesc = table_open(AttributeRelationId, RowExclusiveLock);
/*
* Are we adding the column to a recursion child? If so, check whether to
* merge with an existing definition for the column. If we do merge, we
* must not recurse. Children will already have the column, and recursing
* into them would mess up attinhcount.
*/
if (colDef->inhcount > 0)
{
HeapTuple tuple;
/* Does child already have a column by this name? */
tuple = SearchSysCacheCopyAttName(myrelid, colDef->colname);
if (HeapTupleIsValid(tuple))
{
Form_pg_attribute childatt = (Form_pg_attribute) GETSTRUCT(tuple);
Oid ctypeId;
int32 ctypmod;
Oid ccollid;
/* Child column must match on type, typmod, and collation */
typenameTypeIdAndMod(NULL, colDef->typeName, &ctypeId, &ctypmod);
if (ctypeId != childatt->atttypid ||
ctypmod != childatt->atttypmod)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("child table \"%s\" has different type for column \"%s\"",
RelationGetRelationName(rel), colDef->colname)));
ccollid = GetColumnDefCollation(NULL, colDef, ctypeId);
if (ccollid != childatt->attcollation)
ereport(ERROR,
(errcode(ERRCODE_COLLATION_MISMATCH),
errmsg("child table \"%s\" has different collation for column \"%s\"",
RelationGetRelationName(rel), colDef->colname),
errdetail("\"%s\" versus \"%s\"",
get_collation_name(ccollid),
get_collation_name(childatt->attcollation))));
/* Bump the existing child att's inhcount */
childatt->attinhcount++;
CatalogTupleUpdate(attrdesc, &tuple->t_self, tuple);
heap_freetuple(tuple);
/* Inform the user about the merge */
ereport(NOTICE,
(errmsg("merging definition of column \"%s\" for child \"%s\"",
colDef->colname, RelationGetRelationName(rel))));
table_close(attrdesc, RowExclusiveLock);
return InvalidObjectAddress;
}
}
pgclass = table_open(RelationRelationId, RowExclusiveLock);
reltup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(myrelid));
if (!HeapTupleIsValid(reltup))
elog(ERROR, "cache lookup failed for relation %u", myrelid);
relkind = ((Form_pg_class) GETSTRUCT(reltup))->relkind;
/*
* Cannot add identity column if table has children, because identity does
* not inherit. (Adding column and identity separately will work.)
*/
if (colDef->identity &&
recurse &&
find_inheritance_children(myrelid, NoLock) != NIL)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("cannot recursively add identity column to table that has child tables")));
/* skip if the name already exists and if_not_exists is true */
if (!check_for_column_name_collision(rel, colDef->colname, if_not_exists))
{
table_close(attrdesc, RowExclusiveLock);
heap_freetuple(reltup);
table_close(pgclass, RowExclusiveLock);
return InvalidObjectAddress;
}
/* Determine the new attribute's number */
newattnum = ((Form_pg_class) GETSTRUCT(reltup))->relnatts + 1;
if (newattnum > MaxHeapAttributeNumber)
ereport(ERROR,
(errcode(ERRCODE_TOO_MANY_COLUMNS),
errmsg("tables can have at most %d columns",
MaxHeapAttributeNumber)));
typeTuple = typenameType(NULL, colDef->typeName, &typmod);
tform = (Form_pg_type) GETSTRUCT(typeTuple);
typeOid = tform->oid;
aclresult = pg_type_aclcheck(typeOid, GetUserId(), ACL_USAGE);
if (aclresult != ACLCHECK_OK)
aclcheck_error_type(aclresult, typeOid);
collOid = GetColumnDefCollation(NULL, colDef, typeOid);
/* make sure datatype is legal for a column */
CheckAttributeType(colDef->colname, typeOid, collOid,
list_make1_oid(rel->rd_rel->reltype),
0);
/* construct new attribute's pg_attribute entry */
attribute.attrelid = myrelid;
namestrcpy(&(attribute.attname), colDef->colname);
attribute.atttypid = typeOid;
attribute.attstattarget = (newattnum > 0) ? -1 : 0;
attribute.attlen = tform->typlen;
attribute.atttypmod = typmod;
attribute.attnum = newattnum;
attribute.attbyval = tform->typbyval;
attribute.attndims = list_length(colDef->typeName->arrayBounds);
attribute.attstorage = tform->typstorage;
attribute.attalign = tform->typalign;
attribute.attnotnull = colDef->is_not_null;
attribute.atthasdef = false;
attribute.atthasmissing = false;
attribute.attidentity = colDef->identity;
attribute.attgenerated = colDef->generated;
attribute.attisdropped = false;
attribute.attislocal = colDef->is_local;
attribute.attinhcount = colDef->inhcount;
attribute.attcollation = collOid;
/* attribute.attacl is handled by InsertPgAttributeTuple */
ReleaseSysCache(typeTuple);
InsertPgAttributeTuple(attrdesc, &attribute, NULL);
table_close(attrdesc, RowExclusiveLock);
/*
* Update pg_class tuple as appropriate
*/
((Form_pg_class) GETSTRUCT(reltup))->relnatts = newattnum;
CatalogTupleUpdate(pgclass, &reltup->t_self, reltup);
heap_freetuple(reltup);
/* Post creation hook for new attribute */
InvokeObjectPostCreateHook(RelationRelationId, myrelid, newattnum);
table_close(pgclass, RowExclusiveLock);
/* Make the attribute's catalog entry visible */
CommandCounterIncrement();
/*
* Store the DEFAULT, if any, in the catalogs
*/
if (colDef->raw_default)
{
RawColumnDefault *rawEnt;
rawEnt = (RawColumnDefault *) palloc(sizeof(RawColumnDefault));
rawEnt->attnum = attribute.attnum;
rawEnt->raw_default = copyObject(colDef->raw_default);
/*
* Attempt to skip a complete table rewrite by storing the specified
* DEFAULT value outside of the heap. This may be disabled inside
* AddRelationNewConstraints if the optimization cannot be applied.
*/
rawEnt->missingMode = (!colDef->generated);
rawEnt->generated = colDef->generated;
/*
* This function is intended for CREATE TABLE, so it processes a
* _list_ of defaults, but we just do one.
*/
AddRelationNewConstraints(rel, list_make1(rawEnt), NIL,
false, true, false, NULL);
/* Make the additional catalog changes visible */
CommandCounterIncrement();
/*
* Did the request for a missing value work? If not we'll have to do a
* rewrite
*/
if (!rawEnt->missingMode)
tab->rewrite |= AT_REWRITE_DEFAULT_VAL;
}
/*
* Tell Phase 3 to fill in the default expression, if there is one.
*
* If there is no default, Phase 3 doesn't have to do anything, because
* that effectively means that the default is NULL. The heap tuple access
* routines always check for attnum > # of attributes in tuple, and return
* NULL if so, so without any modification of the tuple data we will get
* the effect of NULL values in the new column.
*
* An exception occurs when the new column is of a domain type: the domain
* might have a NOT NULL constraint, or a check constraint that indirectly
* rejects nulls. If there are any domain constraints then we construct
* an explicit NULL default value that will be passed through
* CoerceToDomain processing. (This is a tad inefficient, since it causes
* rewriting the table which we really don't have to do, but the present
* design of domain processing doesn't offer any simple way of checking
* the constraints more directly.)
*
* Note: we use build_column_default, and not just the cooked default
* returned by AddRelationNewConstraints, so that the right thing happens
* when a datatype's default applies.
*
* We skip this step completely for views and foreign tables. For a view,
* we can only get here from CREATE OR REPLACE VIEW, which historically
* doesn't set up defaults, not even for domain-typed columns. And in any
* case we mustn't invoke Phase 3 on a view or foreign table, since they
* have no storage.
*/
if (relkind != RELKIND_VIEW && relkind != RELKIND_COMPOSITE_TYPE
&& relkind != RELKIND_FOREIGN_TABLE && attribute.attnum > 0)
{
/*
* For an identity column, we can't use build_column_default(),
* because the sequence ownership isn't set yet. So do it manually.
*/
if (colDef->identity)
{
NextValueExpr *nve = makeNode(NextValueExpr);
nve->seqid = RangeVarGetRelid(colDef->identitySequence, NoLock, false);
nve->typeId = typeOid;
defval = (Expr *) nve;
/* must do a rewrite for identity columns */
tab->rewrite |= AT_REWRITE_DEFAULT_VAL;
}
else
defval = (Expr *) build_column_default(rel, attribute.attnum);
if (!defval && DomainHasConstraints(typeOid))
{
Oid baseTypeId;
int32 baseTypeMod;
Oid baseTypeColl;
baseTypeMod = typmod;
baseTypeId = getBaseTypeAndTypmod(typeOid, &baseTypeMod);
baseTypeColl = get_typcollation(baseTypeId);
defval = (Expr *) makeNullConst(baseTypeId, baseTypeMod, baseTypeColl);
defval = (Expr *) coerce_to_target_type(NULL,
(Node *) defval,
baseTypeId,
typeOid,
typmod,
COERCION_ASSIGNMENT,
COERCE_IMPLICIT_CAST,
-1);
if (defval == NULL) /* should not happen */
elog(ERROR, "failed to coerce base type to domain");
}
if (defval)
{
NewColumnValue *newval;
newval = (NewColumnValue *) palloc0(sizeof(NewColumnValue));
newval->attnum = attribute.attnum;
newval->expr = expression_planner(defval);
tab->newvals = lappend(tab->newvals, newval);
}
if (DomainHasConstraints(typeOid))
tab->rewrite |= AT_REWRITE_DEFAULT_VAL;
if (!TupleDescAttr(rel->rd_att, attribute.attnum - 1)->atthasmissing)
{
/*
* If the new column is NOT NULL, and there is no missing value,
* tell Phase 3 it needs to check for NULLs.
*/
tab->verify_new_notnull |= colDef->is_not_null;
}
}
/*
* Add needed dependency entries for the new column.
*/
add_column_datatype_dependency(myrelid, newattnum, attribute.atttypid);
add_column_collation_dependency(myrelid, newattnum, attribute.attcollation);
/*
* Propagate to children as appropriate. Unlike most other ALTER
* routines, we have to do this one level of recursion at a time; we can't
* use find_all_inheritors to do it in one pass.
*/
children = find_inheritance_children(RelationGetRelid(rel), lockmode);
/*
* If we are told not to recurse, there had better not be any child
* tables; else the addition would put them out of step.
*/
if (children && !recurse)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("column must be added to child tables too")));
/* Children should see column as singly inherited */
if (!recursing)
{
colDef = copyObject(colDef);
colDef->inhcount = 1;
colDef->is_local = false;
}
foreach(child, children)
{
Oid childrelid = lfirst_oid(child);
Relation childrel;
AlteredTableInfo *childtab;
/* find_inheritance_children already got lock */
childrel = table_open(childrelid, NoLock);
CheckTableNotInUse(childrel, "ALTER TABLE");
/* Find or create work queue entry for this table */
childtab = ATGetQueueEntry(wqueue, childrel);
/* Recurse to child; return value is ignored */
ATExecAddColumn(wqueue, childtab, childrel,
colDef, recurse, true,
if_not_exists, lockmode);
table_close(childrel, NoLock);
}
ObjectAddressSubSet(address, RelationRelationId, myrelid, newattnum);
return address;
}
/*
* If a new or renamed column will collide with the name of an existing
* column and if_not_exists is false then error out, else do nothing.
*/
static bool
check_for_column_name_collision(Relation rel, const char *colname,
bool if_not_exists)
{
HeapTuple attTuple;
int attnum;
/*
* this test is deliberately not attisdropped-aware, since if one tries to
* add a column matching a dropped column name, it's gonna fail anyway.
*/
attTuple = SearchSysCache2(ATTNAME,
ObjectIdGetDatum(RelationGetRelid(rel)),
PointerGetDatum(colname));
if (!HeapTupleIsValid(attTuple))
return true;
attnum = ((Form_pg_attribute) GETSTRUCT(attTuple))->attnum;
ReleaseSysCache(attTuple);
/*
* We throw a different error message for conflicts with system column
* names, since they are normally not shown and the user might otherwise
* be confused about the reason for the conflict.
*/
if (attnum <= 0)
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_COLUMN),
errmsg("column name \"%s\" conflicts with a system column name",
colname)));
else
{
if (if_not_exists)
{
ereport(NOTICE,
(errcode(ERRCODE_DUPLICATE_COLUMN),
errmsg("column \"%s\" of relation \"%s\" already exists, skipping",
colname, RelationGetRelationName(rel))));
return false;
}
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_COLUMN),
errmsg("column \"%s\" of relation \"%s\" already exists",
colname, RelationGetRelationName(rel))));
}
return true;
}
/*
* Install a column's dependency on its datatype.
*/
static void
add_column_datatype_dependency(Oid relid, int32 attnum, Oid typid)
{
ObjectAddress myself,
referenced;
myself.classId = RelationRelationId;
myself.objectId = relid;
myself.objectSubId = attnum;
referenced.classId = TypeRelationId;
referenced.objectId = typid;
referenced.objectSubId = 0;
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
}
/*
* Install a column's dependency on its collation.
*/
static void
add_column_collation_dependency(Oid relid, int32 attnum, Oid collid)
{
ObjectAddress myself,
referenced;
/* We know the default collation is pinned, so don't bother recording it */
if (OidIsValid(collid) && collid != DEFAULT_COLLATION_OID)
{
myself.classId = RelationRelationId;
myself.objectId = relid;
myself.objectSubId = attnum;
referenced.classId = CollationRelationId;
referenced.objectId = collid;
referenced.objectSubId = 0;
recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
}
}
/*
* ALTER TABLE ALTER COLUMN DROP NOT NULL
*/
static void
ATPrepDropNotNull(Relation rel, bool recurse, bool recursing)
{
/*
* If the parent is a partitioned table, like check constraints, we do not
* support removing the NOT NULL while partitions exist.
*/
if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
{
PartitionDesc partdesc = RelationGetPartitionDesc(rel);
Assert(partdesc != NULL);
if (partdesc->nparts > 0 && !recurse && !recursing)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("cannot remove constraint from only the partitioned table when partitions exist"),
errhint("Do not specify the ONLY keyword.")));
}
}
/*
* Return the address of the modified column. If the column was already
* nullable, InvalidObjectAddress is returned.
*/
static ObjectAddress
ATExecDropNotNull(Relation rel, const char *colName, LOCKMODE lockmode)
{
HeapTuple tuple;
Form_pg_attribute attTup;
AttrNumber attnum;
Relation attr_rel;
List *indexoidlist;
ListCell *indexoidscan;
ObjectAddress address;
/*
* lookup the attribute
*/
attr_rel = table_open(AttributeRelationId, RowExclusiveLock);
tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
if (!HeapTupleIsValid(tuple))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" of relation \"%s\" does not exist",
colName, RelationGetRelationName(rel))));
attTup = (Form_pg_attribute) GETSTRUCT(tuple);
attnum = attTup->attnum;
/* Prevent them from altering a system attribute */
if (attnum <= 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter system column \"%s\"",
colName)));
if (attTup->attidentity)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("column \"%s\" of relation \"%s\" is an identity column",
colName, RelationGetRelationName(rel))));
/*
* Check that the attribute is not in a primary key
*
* Note: we'll throw error even if the pkey index is not valid.
*/
/* Loop over all indexes on the relation */
indexoidlist = RelationGetIndexList(rel);
foreach(indexoidscan, indexoidlist)
{
Oid indexoid = lfirst_oid(indexoidscan);
HeapTuple indexTuple;
Form_pg_index indexStruct;
int i;
indexTuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexoid));
if (!HeapTupleIsValid(indexTuple))
elog(ERROR, "cache lookup failed for index %u", indexoid);
indexStruct = (Form_pg_index) GETSTRUCT(indexTuple);
/* If the index is not a primary key, skip the check */
if (indexStruct->indisprimary)
{
/*
* Loop over each attribute in the primary key and see if it
* matches the to-be-altered attribute
*/
for (i = 0; i < indexStruct->indnkeyatts; i++)
{
if (indexStruct->indkey.values[i] == attnum)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("column \"%s\" is in a primary key",
colName)));
}
}
ReleaseSysCache(indexTuple);
}
list_free(indexoidlist);
/* If rel is partition, shouldn't drop NOT NULL if parent has the same */
if (rel->rd_rel->relispartition)
{
Oid parentId = get_partition_parent(RelationGetRelid(rel));
Relation parent = table_open(parentId, AccessShareLock);
TupleDesc tupDesc = RelationGetDescr(parent);
AttrNumber parent_attnum;
parent_attnum = get_attnum(parentId, colName);
if (TupleDescAttr(tupDesc, parent_attnum - 1)->attnotnull)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("column \"%s\" is marked NOT NULL in parent table",
colName)));
table_close(parent, AccessShareLock);
}
/*
* Okay, actually perform the catalog change ... if needed
*/
if (attTup->attnotnull)
{
attTup->attnotnull = false;
CatalogTupleUpdate(attr_rel, &tuple->t_self, tuple);
ObjectAddressSubSet(address, RelationRelationId,
RelationGetRelid(rel), attnum);
}
else
address = InvalidObjectAddress;
InvokeObjectPostAlterHook(RelationRelationId,
RelationGetRelid(rel), attnum);
table_close(attr_rel, RowExclusiveLock);
return address;
}
/*
* ALTER TABLE ALTER COLUMN SET NOT NULL
*/
static void
ATPrepSetNotNull(List **wqueue, Relation rel,
AlterTableCmd *cmd, bool recurse, bool recursing,
LOCKMODE lockmode)
{
/*
* If we're already recursing, there's nothing to do; the topmost
* invocation of ATSimpleRecursion already visited all children.
*/
if (recursing)
return;
/*
* If we have ALTER TABLE ONLY ... SET NOT NULL on a partitioned table,
* apply ALTER TABLE ... CHECK NOT NULL to every child. Otherwise, use
* normal recursion logic.
*/
if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE &&
!recurse)
{
AlterTableCmd *newcmd = makeNode(AlterTableCmd);
newcmd->subtype = AT_CheckNotNull;
newcmd->name = pstrdup(cmd->name);
ATSimpleRecursion(wqueue, rel, newcmd, true, lockmode);
}
else
ATSimpleRecursion(wqueue, rel, cmd, recurse, lockmode);
}
/*
* Return the address of the modified column. If the column was already NOT
* NULL, InvalidObjectAddress is returned.
*/
static ObjectAddress
ATExecSetNotNull(AlteredTableInfo *tab, Relation rel,
const char *colName, LOCKMODE lockmode)
{
HeapTuple tuple;
AttrNumber attnum;
Relation attr_rel;
ObjectAddress address;
/*
* lookup the attribute
*/
attr_rel = table_open(AttributeRelationId, RowExclusiveLock);
tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
if (!HeapTupleIsValid(tuple))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" of relation \"%s\" does not exist",
colName, RelationGetRelationName(rel))));
attnum = ((Form_pg_attribute) GETSTRUCT(tuple))->attnum;
/* Prevent them from altering a system attribute */
if (attnum <= 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter system column \"%s\"",
colName)));
/*
* Okay, actually perform the catalog change ... if needed
*/
if (!((Form_pg_attribute) GETSTRUCT(tuple))->attnotnull)
{
((Form_pg_attribute) GETSTRUCT(tuple))->attnotnull = true;
CatalogTupleUpdate(attr_rel, &tuple->t_self, tuple);
/*
* Ordinarily phase 3 must ensure that no NULLs exist in columns that
* are set NOT NULL; however, if we can find a constraint which proves
* this then we can skip that. We needn't bother looking if we've
* already found that we must verify some other NOT NULL constraint.
*/
if (!tab->verify_new_notnull &&
!NotNullImpliedByRelConstraints(rel, (Form_pg_attribute) GETSTRUCT(tuple)))
{
/* Tell Phase 3 it needs to test the constraint */
tab->verify_new_notnull = true;
}
ObjectAddressSubSet(address, RelationRelationId,
RelationGetRelid(rel), attnum);
}
else
address = InvalidObjectAddress;
InvokeObjectPostAlterHook(RelationRelationId,
RelationGetRelid(rel), attnum);
table_close(attr_rel, RowExclusiveLock);
return address;
}
/*
* ALTER TABLE ALTER COLUMN CHECK NOT NULL
*
* This doesn't exist in the grammar, but we generate AT_CheckNotNull
* commands against the partitions of a partitioned table if the user
* writes ALTER TABLE ONLY ... SET NOT NULL on the partitioned table,
* or tries to create a primary key on it (which internally creates
* AT_SetNotNull on the partitioned table). Such a command doesn't
* allow us to actually modify any partition, but we want to let it
* go through if the partitions are already properly marked.
*
* In future, this might need to adjust the child table's state, likely
* by incrementing an inheritance count for the attnotnull constraint.
* For now we need only check for the presence of the flag.
*/
static void
ATExecCheckNotNull(AlteredTableInfo *tab, Relation rel,
const char *colName, LOCKMODE lockmode)
{
HeapTuple tuple;
tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName);
if (!HeapTupleIsValid(tuple))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" of relation \"%s\" does not exist",
colName, RelationGetRelationName(rel))));
if (!((Form_pg_attribute) GETSTRUCT(tuple))->attnotnull)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("constraint must be added to child tables too"),
errdetail("Column \"%s\" of relation \"%s\" is not already NOT NULL.",
colName, RelationGetRelationName(rel)),
errhint("Do not specify the ONLY keyword.")));
ReleaseSysCache(tuple);
}
/*
* NotNullImpliedByRelConstraints
* Does rel's existing constraints imply NOT NULL for the given attribute?
*/
static bool
NotNullImpliedByRelConstraints(Relation rel, Form_pg_attribute attr)
{
NullTest *nnulltest = makeNode(NullTest);
nnulltest->arg = (Expr *) makeVar(1,
attr->attnum,
attr->atttypid,
attr->atttypmod,
attr->attcollation,
0);
nnulltest->nulltesttype = IS_NOT_NULL;
/*
* argisrow = false is correct even for a composite column, because
* attnotnull does not represent a SQL-spec IS NOT NULL test in such a
* case, just IS DISTINCT FROM NULL.
*/
nnulltest->argisrow = false;
nnulltest->location = -1;
if (ConstraintImpliedByRelConstraint(rel, list_make1(nnulltest), NIL))
{
ereport(DEBUG1,
(errmsg("existing constraints on column \"%s\".\"%s\" are sufficient to prove that it does not contain nulls",
RelationGetRelationName(rel), NameStr(attr->attname))));
return true;
}
return false;
}
/*
* ALTER TABLE ALTER COLUMN SET/DROP DEFAULT
*
* Return the address of the affected column.
*/
static ObjectAddress
ATExecColumnDefault(Relation rel, const char *colName,
Node *newDefault, LOCKMODE lockmode)
{
TupleDesc tupdesc = RelationGetDescr(rel);
AttrNumber attnum;
ObjectAddress address;
/*
* get the number of the attribute
*/
attnum = get_attnum(RelationGetRelid(rel), colName);
if (attnum == InvalidAttrNumber)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" of relation \"%s\" does not exist",
colName, RelationGetRelationName(rel))));
/* Prevent them from altering a system attribute */
if (attnum <= 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter system column \"%s\"",
colName)));
if (TupleDescAttr(tupdesc, attnum - 1)->attidentity)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("column \"%s\" of relation \"%s\" is an identity column",
colName, RelationGetRelationName(rel)),
newDefault ? 0 : errhint("Use ALTER TABLE ... ALTER COLUMN ... DROP IDENTITY instead.")));
if (TupleDescAttr(tupdesc, attnum - 1)->attgenerated)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("column \"%s\" of relation \"%s\" is a generated column",
colName, RelationGetRelationName(rel))));
/*
* Remove any old default for the column. We use RESTRICT here for
* safety, but at present we do not expect anything to depend on the
* default.
*
* We treat removing the existing default as an internal operation when it
* is preparatory to adding a new default, but as a user-initiated
* operation when the user asked for a drop.
*/
RemoveAttrDefault(RelationGetRelid(rel), attnum, DROP_RESTRICT, false,
newDefault == NULL ? false : true);
if (newDefault)
{
/* SET DEFAULT */
RawColumnDefault *rawEnt;
rawEnt = (RawColumnDefault *) palloc(sizeof(RawColumnDefault));
rawEnt->attnum = attnum;
rawEnt->raw_default = newDefault;
rawEnt->missingMode = false;
rawEnt->generated = '\0';
/*
* This function is intended for CREATE TABLE, so it processes a
* _list_ of defaults, but we just do one.
*/
AddRelationNewConstraints(rel, list_make1(rawEnt), NIL,
false, true, false, NULL);
}
ObjectAddressSubSet(address, RelationRelationId,
RelationGetRelid(rel), attnum);
return address;
}
/*
* ALTER TABLE ALTER COLUMN ADD IDENTITY
*
* Return the address of the affected column.
*/
static ObjectAddress
ATExecAddIdentity(Relation rel, const char *colName,
Node *def, LOCKMODE lockmode)
{
Relation attrelation;
HeapTuple tuple;
Form_pg_attribute attTup;
AttrNumber attnum;
ObjectAddress address;
ColumnDef *cdef = castNode(ColumnDef, def);
attrelation = table_open(AttributeRelationId, RowExclusiveLock);
tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
if (!HeapTupleIsValid(tuple))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" of relation \"%s\" does not exist",
colName, RelationGetRelationName(rel))));
attTup = (Form_pg_attribute) GETSTRUCT(tuple);
attnum = attTup->attnum;
/* Can't alter a system attribute */
if (attnum <= 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter system column \"%s\"",
colName)));
/*
* Creating a column as identity implies NOT NULL, so adding the identity
* to an existing column that is not NOT NULL would create a state that
* cannot be reproduced without contortions.
*/
if (!attTup->attnotnull)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("column \"%s\" of relation \"%s\" must be declared NOT NULL before identity can be added",
colName, RelationGetRelationName(rel))));
if (attTup->attidentity)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("column \"%s\" of relation \"%s\" is already an identity column",
colName, RelationGetRelationName(rel))));
if (attTup->atthasdef)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("column \"%s\" of relation \"%s\" already has a default value",
colName, RelationGetRelationName(rel))));
attTup->attidentity = cdef->identity;
CatalogTupleUpdate(attrelation, &tuple->t_self, tuple);
InvokeObjectPostAlterHook(RelationRelationId,
RelationGetRelid(rel),
attTup->attnum);
ObjectAddressSubSet(address, RelationRelationId,
RelationGetRelid(rel), attnum);
heap_freetuple(tuple);
table_close(attrelation, RowExclusiveLock);
return address;
}
/*
* ALTER TABLE ALTER COLUMN SET { GENERATED or sequence options }
*
* Return the address of the affected column.
*/
static ObjectAddress
ATExecSetIdentity(Relation rel, const char *colName, Node *def, LOCKMODE lockmode)
{
ListCell *option;
DefElem *generatedEl = NULL;
HeapTuple tuple;
Form_pg_attribute attTup;
AttrNumber attnum;
Relation attrelation;
ObjectAddress address;
foreach(option, castNode(List, def))
{
DefElem *defel = lfirst_node(DefElem, option);
if (strcmp(defel->defname, "generated") == 0)
{
if (generatedEl)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("conflicting or redundant options")));
generatedEl = defel;
}
else
elog(ERROR, "option \"%s\" not recognized",
defel->defname);
}
/*
* Even if there is nothing to change here, we run all the checks. There
* will be a subsequent ALTER SEQUENCE that relies on everything being
* there.
*/
attrelation = table_open(AttributeRelationId, RowExclusiveLock);
tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
if (!HeapTupleIsValid(tuple))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" of relation \"%s\" does not exist",
colName, RelationGetRelationName(rel))));
attTup = (Form_pg_attribute) GETSTRUCT(tuple);
attnum = attTup->attnum;
if (attnum <= 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter system column \"%s\"",
colName)));
if (!attTup->attidentity)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("column \"%s\" of relation \"%s\" is not an identity column",
colName, RelationGetRelationName(rel))));
if (generatedEl)
{
attTup->attidentity = defGetInt32(generatedEl);
CatalogTupleUpdate(attrelation, &tuple->t_self, tuple);
InvokeObjectPostAlterHook(RelationRelationId,
RelationGetRelid(rel),
attTup->attnum);
ObjectAddressSubSet(address, RelationRelationId,
RelationGetRelid(rel), attnum);
}
else
address = InvalidObjectAddress;
heap_freetuple(tuple);
table_close(attrelation, RowExclusiveLock);
return address;
}
/*
* ALTER TABLE ALTER COLUMN DROP IDENTITY
*
* Return the address of the affected column.
*/
static ObjectAddress
ATExecDropIdentity(Relation rel, const char *colName, bool missing_ok, LOCKMODE lockmode)
{
HeapTuple tuple;
Form_pg_attribute attTup;
AttrNumber attnum;
Relation attrelation;
ObjectAddress address;
Oid seqid;
ObjectAddress seqaddress;
attrelation = table_open(AttributeRelationId, RowExclusiveLock);
tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
if (!HeapTupleIsValid(tuple))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" of relation \"%s\" does not exist",
colName, RelationGetRelationName(rel))));
attTup = (Form_pg_attribute) GETSTRUCT(tuple);
attnum = attTup->attnum;
if (attnum <= 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter system column \"%s\"",
colName)));
if (!attTup->attidentity)
{
if (!missing_ok)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("column \"%s\" of relation \"%s\" is not an identity column",
colName, RelationGetRelationName(rel))));
else
{
ereport(NOTICE,
(errmsg("column \"%s\" of relation \"%s\" is not an identity column, skipping",
colName, RelationGetRelationName(rel))));
heap_freetuple(tuple);
table_close(attrelation, RowExclusiveLock);
return InvalidObjectAddress;
}
}
attTup->attidentity = '\0';
CatalogTupleUpdate(attrelation, &tuple->t_self, tuple);
InvokeObjectPostAlterHook(RelationRelationId,
RelationGetRelid(rel),
attTup->attnum);
ObjectAddressSubSet(address, RelationRelationId,
RelationGetRelid(rel), attnum);
heap_freetuple(tuple);
table_close(attrelation, RowExclusiveLock);
/* drop the internal sequence */
seqid = getIdentitySequence(RelationGetRelid(rel), attnum, false);
deleteDependencyRecordsForClass(RelationRelationId, seqid,
RelationRelationId, DEPENDENCY_INTERNAL);
CommandCounterIncrement();
seqaddress.classId = RelationRelationId;
seqaddress.objectId = seqid;
seqaddress.objectSubId = 0;
performDeletion(&seqaddress, DROP_RESTRICT, PERFORM_DELETION_INTERNAL);
return address;
}
/*
* ALTER TABLE ALTER COLUMN SET STATISTICS
*/
static void
ATPrepSetStatistics(Relation rel, const char *colName, int16 colNum, Node *newValue, LOCKMODE lockmode)
{
/*
* We do our own permission checking because (a) we want to allow SET
* STATISTICS on indexes (for expressional index columns), and (b) we want
* to allow SET STATISTICS on system catalogs without requiring
* allowSystemTableMods to be turned on.
*/
if (rel->rd_rel->relkind != RELKIND_RELATION &&
rel->rd_rel->relkind != RELKIND_MATVIEW &&
rel->rd_rel->relkind != RELKIND_INDEX &&
rel->rd_rel->relkind != RELKIND_PARTITIONED_INDEX &&
rel->rd_rel->relkind != RELKIND_FOREIGN_TABLE &&
rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a table, materialized view, index, or foreign table",
RelationGetRelationName(rel))));
/*
* We allow referencing columns by numbers only for indexes, since table
* column numbers could contain gaps if columns are later dropped.
*/
if (rel->rd_rel->relkind != RELKIND_INDEX &&
rel->rd_rel->relkind != RELKIND_PARTITIONED_INDEX &&
!colName)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot refer to non-index column by number")));
/* Permissions checks */
if (!pg_class_ownercheck(RelationGetRelid(rel), GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(rel->rd_rel->relkind),
RelationGetRelationName(rel));
}
/*
* Return value is the address of the modified column
*/
static ObjectAddress
ATExecSetStatistics(Relation rel, const char *colName, int16 colNum, Node *newValue, LOCKMODE lockmode)
{
int newtarget;
Relation attrelation;
HeapTuple tuple;
Form_pg_attribute attrtuple;
AttrNumber attnum;
ObjectAddress address;
Assert(IsA(newValue, Integer));
newtarget = intVal(newValue);
/*
* Limit target to a sane range
*/
if (newtarget < -1)
{
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("statistics target %d is too low",
newtarget)));
}
else if (newtarget > 10000)
{
newtarget = 10000;
ereport(WARNING,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("lowering statistics target to %d",
newtarget)));
}
attrelation = table_open(AttributeRelationId, RowExclusiveLock);
if (colName)
{
tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
if (!HeapTupleIsValid(tuple))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" of relation \"%s\" does not exist",
colName, RelationGetRelationName(rel))));
}
else
{
tuple = SearchSysCacheCopyAttNum(RelationGetRelid(rel), colNum);
if (!HeapTupleIsValid(tuple))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column number %d of relation \"%s\" does not exist",
colNum, RelationGetRelationName(rel))));
}
attrtuple = (Form_pg_attribute) GETSTRUCT(tuple);
attnum = attrtuple->attnum;
if (attnum <= 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter system column \"%s\"",
colName)));
if (rel->rd_rel->relkind == RELKIND_INDEX ||
rel->rd_rel->relkind == RELKIND_PARTITIONED_INDEX)
{
if (attnum > rel->rd_index->indnkeyatts)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter statistics on included column \"%s\" of index \"%s\"",
NameStr(attrtuple->attname), RelationGetRelationName(rel))));
else if (rel->rd_index->indkey.values[attnum - 1] != 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter statistics on non-expression column \"%s\" of index \"%s\"",
NameStr(attrtuple->attname), RelationGetRelationName(rel)),
errhint("Alter statistics on table column instead.")));
}
attrtuple->attstattarget = newtarget;
CatalogTupleUpdate(attrelation, &tuple->t_self, tuple);
InvokeObjectPostAlterHook(RelationRelationId,
RelationGetRelid(rel),
attrtuple->attnum);
ObjectAddressSubSet(address, RelationRelationId,
RelationGetRelid(rel), attnum);
heap_freetuple(tuple);
table_close(attrelation, RowExclusiveLock);
return address;
}
/*
* Return value is the address of the modified column
*/
static ObjectAddress
ATExecSetOptions(Relation rel, const char *colName, Node *options,
bool isReset, LOCKMODE lockmode)
{
Relation attrelation;
HeapTuple tuple,
newtuple;
Form_pg_attribute attrtuple;
AttrNumber attnum;
Datum datum,
newOptions;
bool isnull;
ObjectAddress address;
Datum repl_val[Natts_pg_attribute];
bool repl_null[Natts_pg_attribute];
bool repl_repl[Natts_pg_attribute];
attrelation = table_open(AttributeRelationId, RowExclusiveLock);
tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName);
if (!HeapTupleIsValid(tuple))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" of relation \"%s\" does not exist",
colName, RelationGetRelationName(rel))));
attrtuple = (Form_pg_attribute) GETSTRUCT(tuple);
attnum = attrtuple->attnum;
if (attnum <= 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter system column \"%s\"",
colName)));
/* Generate new proposed attoptions (text array) */
datum = SysCacheGetAttr(ATTNAME, tuple, Anum_pg_attribute_attoptions,
&isnull);
newOptions = transformRelOptions(isnull ? (Datum) 0 : datum,
castNode(List, options), NULL, NULL,
false, isReset);
/* Validate new options */
(void) attribute_reloptions(newOptions, true);
/* Build new tuple. */
memset(repl_null, false, sizeof(repl_null));
memset(repl_repl, false, sizeof(repl_repl));
if (newOptions != (Datum) 0)
repl_val[Anum_pg_attribute_attoptions - 1] = newOptions;
else
repl_null[Anum_pg_attribute_attoptions - 1] = true;
repl_repl[Anum_pg_attribute_attoptions - 1] = true;
newtuple = heap_modify_tuple(tuple, RelationGetDescr(attrelation),
repl_val, repl_null, repl_repl);
/* Update system catalog. */
CatalogTupleUpdate(attrelation, &newtuple->t_self, newtuple);
InvokeObjectPostAlterHook(RelationRelationId,
RelationGetRelid(rel),
attrtuple->attnum);
ObjectAddressSubSet(address, RelationRelationId,
RelationGetRelid(rel), attnum);
heap_freetuple(newtuple);
ReleaseSysCache(tuple);
table_close(attrelation, RowExclusiveLock);
return address;
}
/*
* ALTER TABLE ALTER COLUMN SET STORAGE
*
* Return value is the address of the modified column
*/
static ObjectAddress
ATExecSetStorage(Relation rel, const char *colName, Node *newValue, LOCKMODE lockmode)
{
char *storagemode;
char newstorage;
Relation attrelation;
HeapTuple tuple;
Form_pg_attribute attrtuple;
AttrNumber attnum;
ObjectAddress address;
Assert(IsA(newValue, String));
storagemode = strVal(newValue);
if (pg_strcasecmp(storagemode, "plain") == 0)
newstorage = 'p';
else if (pg_strcasecmp(storagemode, "external") == 0)
newstorage = 'e';
else if (pg_strcasecmp(storagemode, "extended") == 0)
newstorage = 'x';
else if (pg_strcasecmp(storagemode, "main") == 0)
newstorage = 'm';
else
{
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("invalid storage type \"%s\"",
storagemode)));
newstorage = 0; /* keep compiler quiet */
}
attrelation = table_open(AttributeRelationId, RowExclusiveLock);
tuple = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
if (!HeapTupleIsValid(tuple))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" of relation \"%s\" does not exist",
colName, RelationGetRelationName(rel))));
attrtuple = (Form_pg_attribute) GETSTRUCT(tuple);
attnum = attrtuple->attnum;
if (attnum <= 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter system column \"%s\"",
colName)));
/*
* safety check: do not allow toasted storage modes unless column datatype
* is TOAST-aware.
*/
if (newstorage == 'p' || TypeIsToastable(attrtuple->atttypid))
attrtuple->attstorage = newstorage;
else
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("column data type %s can only have storage PLAIN",
format_type_be(attrtuple->atttypid))));
CatalogTupleUpdate(attrelation, &tuple->t_self, tuple);
InvokeObjectPostAlterHook(RelationRelationId,
RelationGetRelid(rel),
attrtuple->attnum);
heap_freetuple(tuple);
table_close(attrelation, RowExclusiveLock);
ObjectAddressSubSet(address, RelationRelationId,
RelationGetRelid(rel), attnum);
return address;
}
/*
* ALTER TABLE DROP COLUMN
*
* DROP COLUMN cannot use the normal ALTER TABLE recursion mechanism,
* because we have to decide at runtime whether to recurse or not depending
* on whether attinhcount goes to zero or not. (We can't check this in a
* static pre-pass because it won't handle multiple inheritance situations
* correctly.)
*/
static void
ATPrepDropColumn(List **wqueue, Relation rel, bool recurse, bool recursing,
AlterTableCmd *cmd, LOCKMODE lockmode)
{
if (rel->rd_rel->reloftype && !recursing)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot drop column from typed table")));
if (rel->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
ATTypedTableRecursion(wqueue, rel, cmd, lockmode);
if (recurse)
cmd->subtype = AT_DropColumnRecurse;
}
/*
* Drops column 'colName' from relation 'rel' and returns the address of the
* dropped column. The column is also dropped (or marked as no longer
* inherited from relation) from the relation's inheritance children, if any.
*
* In the recursive invocations for inheritance child relations, instead of
* dropping the column directly (if to be dropped at all), its object address
* is added to 'addrs', which must be non-NULL in such invocations. All
* columns are dropped at the same time after all the children have been
* checked recursively.
*/
static ObjectAddress
ATExecDropColumn(List **wqueue, Relation rel, const char *colName,
DropBehavior behavior,
bool recurse, bool recursing,
bool missing_ok, LOCKMODE lockmode,
ObjectAddresses *addrs)
{
HeapTuple tuple;
Form_pg_attribute targetatt;
AttrNumber attnum;
List *children;
ObjectAddress object;
bool is_expr;
/* At top level, permission check was done in ATPrepCmd, else do it */
if (recursing)
ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
/* Initialize addrs on the first invocation */
Assert(!recursing || addrs != NULL);
if (!recursing)
addrs = new_object_addresses();
/*
* get the number of the attribute
*/
tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName);
if (!HeapTupleIsValid(tuple))
{
if (!missing_ok)
{
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" of relation \"%s\" does not exist",
colName, RelationGetRelationName(rel))));
}
else
{
ereport(NOTICE,
(errmsg("column \"%s\" of relation \"%s\" does not exist, skipping",
colName, RelationGetRelationName(rel))));
return InvalidObjectAddress;
}
}
targetatt = (Form_pg_attribute) GETSTRUCT(tuple);
attnum = targetatt->attnum;
/* Can't drop a system attribute */
if (attnum <= 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot drop system column \"%s\"",
colName)));
/*
* Don't drop inherited columns, unless recursing (presumably from a drop
* of the parent column)
*/
if (targetatt->attinhcount > 0 && !recursing)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("cannot drop inherited column \"%s\"",
colName)));
/*
* Don't drop columns used in the partition key, either. (If we let this
* go through, the key column's dependencies would cause a cascaded drop
* of the whole table, which is surely not what the user expected.)
*/
if (has_partition_attrs(rel,
bms_make_singleton(attnum - FirstLowInvalidHeapAttributeNumber),
&is_expr))
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("cannot drop column \"%s\" because it is part of the partition key of relation \"%s\"",
colName, RelationGetRelationName(rel))));
ReleaseSysCache(tuple);
/*
* Propagate to children as appropriate. Unlike most other ALTER
* routines, we have to do this one level of recursion at a time; we can't
* use find_all_inheritors to do it in one pass.
*/
children = find_inheritance_children(RelationGetRelid(rel), lockmode);
if (children)
{
Relation attr_rel;
ListCell *child;
/*
* In case of a partitioned table, the column must be dropped from the
* partitions as well.
*/
if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE && !recurse)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("cannot drop column from only the partitioned table when partitions exist"),
errhint("Do not specify the ONLY keyword.")));
attr_rel = table_open(AttributeRelationId, RowExclusiveLock);
foreach(child, children)
{
Oid childrelid = lfirst_oid(child);
Relation childrel;
Form_pg_attribute childatt;
/* find_inheritance_children already got lock */
childrel = table_open(childrelid, NoLock);
CheckTableNotInUse(childrel, "ALTER TABLE");
tuple = SearchSysCacheCopyAttName(childrelid, colName);
if (!HeapTupleIsValid(tuple)) /* shouldn't happen */
elog(ERROR, "cache lookup failed for attribute \"%s\" of relation %u",
colName, childrelid);
childatt = (Form_pg_attribute) GETSTRUCT(tuple);
if (childatt->attinhcount <= 0) /* shouldn't happen */
elog(ERROR, "relation %u has non-inherited attribute \"%s\"",
childrelid, colName);
if (recurse)
{
/*
* If the child column has other definition sources, just
* decrement its inheritance count; if not, recurse to delete
* it.
*/
if (childatt->attinhcount == 1 && !childatt->attislocal)
{
/* Time to delete this child column, too */
ATExecDropColumn(wqueue, childrel, colName,
behavior, true, true,
false, lockmode, addrs);
}
else
{
/* Child column must survive my deletion */
childatt->attinhcount--;
CatalogTupleUpdate(attr_rel, &tuple->t_self, tuple);
/* Make update visible */
CommandCounterIncrement();
}
}
else
{
/*
* If we were told to drop ONLY in this table (no recursion),
* we need to mark the inheritors' attributes as locally
* defined rather than inherited.
*/
childatt->attinhcount--;
childatt->attislocal = true;
CatalogTupleUpdate(attr_rel, &tuple->t_self, tuple);
/* Make update visible */
CommandCounterIncrement();
}
heap_freetuple(tuple);
table_close(childrel, NoLock);
}
table_close(attr_rel, RowExclusiveLock);
}
/* Add object to delete */
object.classId = RelationRelationId;
object.objectId = RelationGetRelid(rel);
object.objectSubId = attnum;
add_exact_object_address(&object, addrs);
if (!recursing)
{
/* Recursion has ended, drop everything that was collected */
performMultipleDeletions(addrs, behavior, 0);
free_object_addresses(addrs);
}
return object;
}
/*
* ALTER TABLE ADD INDEX
*
* There is no such command in the grammar, but parse_utilcmd.c converts
* UNIQUE and PRIMARY KEY constraints into AT_AddIndex subcommands. This lets
* us schedule creation of the index at the appropriate time during ALTER.
*
* Return value is the address of the new index.
*/
static ObjectAddress
ATExecAddIndex(AlteredTableInfo *tab, Relation rel,
IndexStmt *stmt, bool is_rebuild, LOCKMODE lockmode)
{
bool check_rights;
bool skip_build;
bool quiet;
ObjectAddress address;
Assert(IsA(stmt, IndexStmt));
Assert(!stmt->concurrent);
/* The IndexStmt has already been through transformIndexStmt */
Assert(stmt->transformed);
/* suppress schema rights check when rebuilding existing index */
check_rights = !is_rebuild;
/* skip index build if phase 3 will do it or we're reusing an old one */
skip_build = tab->rewrite > 0 || OidIsValid(stmt->oldNode);
/* suppress notices when rebuilding existing index */
quiet = is_rebuild;
address = DefineIndex(RelationGetRelid(rel),
stmt,
InvalidOid, /* no predefined OID */
InvalidOid, /* no parent index */
InvalidOid, /* no parent constraint */
true, /* is_alter_table */
check_rights,
false, /* check_not_in_use - we did it already */
skip_build,
quiet);
/*
* If TryReuseIndex() stashed a relfilenode for us, we used it for the new
* index instead of building from scratch. The DROP of the old edition of
* this index will have scheduled the storage for deletion at commit, so
* cancel that pending deletion.
*/
if (OidIsValid(stmt->oldNode))
{
Relation irel = index_open(address.objectId, NoLock);
RelationPreserveStorage(irel->rd_node, true);
index_close(irel, NoLock);
}
return address;
}
/*
* ALTER TABLE ADD CONSTRAINT USING INDEX
*
* Returns the address of the new constraint.
*/
static ObjectAddress
ATExecAddIndexConstraint(AlteredTableInfo *tab, Relation rel,
IndexStmt *stmt, LOCKMODE lockmode)
{
Oid index_oid = stmt->indexOid;
Relation indexRel;
char *indexName;
IndexInfo *indexInfo;
char *constraintName;
char constraintType;
ObjectAddress address;
bits16 flags;
Assert(IsA(stmt, IndexStmt));
Assert(OidIsValid(index_oid));
Assert(stmt->isconstraint);
/*
* Doing this on partitioned tables is not a simple feature to implement,
* so let's punt for now.
*/
if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("ALTER TABLE / ADD CONSTRAINT USING INDEX is not supported on partitioned tables")));
indexRel = index_open(index_oid, AccessShareLock);
indexName = pstrdup(RelationGetRelationName(indexRel));
indexInfo = BuildIndexInfo(indexRel);
/* this should have been checked at parse time */
if (!indexInfo->ii_Unique)
elog(ERROR, "index \"%s\" is not unique", indexName);
/*
* Determine name to assign to constraint. We require a constraint to
* have the same name as the underlying index; therefore, use the index's
* existing name as the default constraint name, and if the user
* explicitly gives some other name for the constraint, rename the index
* to match.
*/
constraintName = stmt->idxname;
if (constraintName == NULL)
constraintName = indexName;
else if (strcmp(constraintName, indexName) != 0)
{
ereport(NOTICE,
(errmsg("ALTER TABLE / ADD CONSTRAINT USING INDEX will rename index \"%s\" to \"%s\"",
indexName, constraintName)));
RenameRelationInternal(index_oid, constraintName, false, true);
}
/* Extra checks needed if making primary key */
if (stmt->primary)
index_check_primary_key(rel, indexInfo, true, stmt);
/* Note we currently don't support EXCLUSION constraints here */
if (stmt->primary)
constraintType = CONSTRAINT_PRIMARY;
else
constraintType = CONSTRAINT_UNIQUE;
/* Create the catalog entries for the constraint */
flags = INDEX_CONSTR_CREATE_UPDATE_INDEX |
INDEX_CONSTR_CREATE_REMOVE_OLD_DEPS |
(stmt->initdeferred ? INDEX_CONSTR_CREATE_INIT_DEFERRED : 0) |
(stmt->deferrable ? INDEX_CONSTR_CREATE_DEFERRABLE : 0) |
(stmt->primary ? INDEX_CONSTR_CREATE_MARK_AS_PRIMARY : 0);
address = index_constraint_create(rel,
index_oid,
InvalidOid,
indexInfo,
constraintName,
constraintType,
flags,
allowSystemTableMods,
false); /* is_internal */
index_close(indexRel, NoLock);
return address;
}
/*
* ALTER TABLE ADD CONSTRAINT
*
* Return value is the address of the new constraint; if no constraint was
* added, InvalidObjectAddress is returned.
*/
static ObjectAddress
ATExecAddConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
Constraint *newConstraint, bool recurse, bool is_readd,
LOCKMODE lockmode)
{
ObjectAddress address = InvalidObjectAddress;
Assert(IsA(newConstraint, Constraint));
/*
* Currently, we only expect to see CONSTR_CHECK and CONSTR_FOREIGN nodes
* arriving here (see the preprocessing done in parse_utilcmd.c). Use a
* switch anyway to make it easier to add more code later.
*/
switch (newConstraint->contype)
{
case CONSTR_CHECK:
address =
ATAddCheckConstraint(wqueue, tab, rel,
newConstraint, recurse, false, is_readd,
lockmode);
break;
case CONSTR_FOREIGN:
/*
* Assign or validate constraint name
*/
if (newConstraint->conname)
{
if (ConstraintNameIsUsed(CONSTRAINT_RELATION,
RelationGetRelid(rel),
newConstraint->conname))
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_OBJECT),
errmsg("constraint \"%s\" for relation \"%s\" already exists",
newConstraint->conname,
RelationGetRelationName(rel))));
}
else
newConstraint->conname =
ChooseConstraintName(RelationGetRelationName(rel),
ChooseForeignKeyConstraintNameAddition(newConstraint->fk_attrs),
"fkey",
RelationGetNamespace(rel),
NIL);
address = ATAddForeignKeyConstraint(wqueue, tab, rel,
newConstraint, InvalidOid,
recurse, false,
lockmode);
break;
default:
elog(ERROR, "unrecognized constraint type: %d",
(int) newConstraint->contype);
}
return address;
}
/*
* Generate the column-name portion of the constraint name for a new foreign
* key given the list of column names that reference the referenced
* table. This will be passed to ChooseConstraintName along with the parent
* table name and the "fkey" suffix.
*
* We know that less than NAMEDATALEN characters will actually be used, so we
* can truncate the result once we've generated that many.
*
* XXX see also ChooseExtendedStatisticNameAddition and
* ChooseIndexNameAddition.
*/
static char *
ChooseForeignKeyConstraintNameAddition(List *colnames)
{
char buf[NAMEDATALEN * 2];
int buflen = 0;
ListCell *lc;
buf[0] = '\0';
foreach(lc, colnames)
{
const char *name = strVal(lfirst(lc));
if (buflen > 0)
buf[buflen++] = '_'; /* insert _ between names */
/*
* At this point we have buflen <= NAMEDATALEN. name should be less
* than NAMEDATALEN already, but use strlcpy for paranoia.
*/
strlcpy(buf + buflen, name, NAMEDATALEN);
buflen += strlen(buf + buflen);
if (buflen >= NAMEDATALEN)
break;
}
return pstrdup(buf);
}
/*
* Add a check constraint to a single table and its children. Returns the
* address of the constraint added to the parent relation, if one gets added,
* or InvalidObjectAddress otherwise.
*
* Subroutine for ATExecAddConstraint.
*
* We must recurse to child tables during execution, rather than using
* ALTER TABLE's normal prep-time recursion. The reason is that all the
* constraints *must* be given the same name, else they won't be seen as
* related later. If the user didn't explicitly specify a name, then
* AddRelationNewConstraints would normally assign different names to the
* child constraints. To fix that, we must capture the name assigned at
* the parent table and pass that down.
*/
static ObjectAddress
ATAddCheckConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
Constraint *constr, bool recurse, bool recursing,
bool is_readd, LOCKMODE lockmode)
{
List *newcons;
ListCell *lcon;
List *children;
ListCell *child;
ObjectAddress address = InvalidObjectAddress;
/* At top level, permission check was done in ATPrepCmd, else do it */
if (recursing)
ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
/*
* Call AddRelationNewConstraints to do the work, making sure it works on
* a copy of the Constraint so transformExpr can't modify the original. It
* returns a list of cooked constraints.
*
* If the constraint ends up getting merged with a pre-existing one, it's
* omitted from the returned list, which is what we want: we do not need
* to do any validation work. That can only happen at child tables,
* though, since we disallow merging at the top level.
*/
newcons = AddRelationNewConstraints(rel, NIL,
list_make1(copyObject(constr)),
recursing | is_readd, /* allow_merge */
!recursing, /* is_local */
is_readd, /* is_internal */
NULL); /* queryString not available
* here */
/* we don't expect more than one constraint here */
Assert(list_length(newcons) <= 1);
/* Add each to-be-validated constraint to Phase 3's queue */
foreach(lcon, newcons)
{
CookedConstraint *ccon = (CookedConstraint *) lfirst(lcon);
if (!ccon->skip_validation)
{
NewConstraint *newcon;
newcon = (NewConstraint *) palloc0(sizeof(NewConstraint));
newcon->name = ccon->name;
newcon->contype = ccon->contype;
newcon->qual = ccon->expr;
tab->constraints = lappend(tab->constraints, newcon);
}
/* Save the actually assigned name if it was defaulted */
if (constr->conname == NULL)
constr->conname = ccon->name;
ObjectAddressSet(address, ConstraintRelationId, ccon->conoid);
}
/* At this point we must have a locked-down name to use */
Assert(constr->conname != NULL);
/* Advance command counter in case same table is visited multiple times */
CommandCounterIncrement();
/*
* If the constraint got merged with an existing constraint, we're done.
* We mustn't recurse to child tables in this case, because they've
* already got the constraint, and visiting them again would lead to an
* incorrect value for coninhcount.
*/
if (newcons == NIL)
return address;
/*
* If adding a NO INHERIT constraint, no need to find our children.
*/
if (constr->is_no_inherit)
return address;
/*
* Propagate to children as appropriate. Unlike most other ALTER
* routines, we have to do this one level of recursion at a time; we can't
* use find_all_inheritors to do it in one pass.
*/
children = find_inheritance_children(RelationGetRelid(rel), lockmode);
/*
* Check if ONLY was specified with ALTER TABLE. If so, allow the
* constraint creation only if there are no children currently. Error out
* otherwise.
*/
if (!recurse && children != NIL)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("constraint must be added to child tables too")));
foreach(child, children)
{
Oid childrelid = lfirst_oid(child);
Relation childrel;
AlteredTableInfo *childtab;
/* find_inheritance_children already got lock */
childrel = table_open(childrelid, NoLock);
CheckTableNotInUse(childrel, "ALTER TABLE");
/* Find or create work queue entry for this table */
childtab = ATGetQueueEntry(wqueue, childrel);
/* Recurse to child */
ATAddCheckConstraint(wqueue, childtab, childrel,
constr, recurse, true, is_readd, lockmode);
table_close(childrel, NoLock);
}
return address;
}
/*
* Add a foreign-key constraint to a single table; return the new constraint's
* address.
*
* Subroutine for ATExecAddConstraint. Must already hold exclusive
* lock on the rel, and have done appropriate validity checks for it.
* We do permissions checks here, however.
*
* When the referenced or referencing tables (or both) are partitioned,
* multiple pg_constraint rows are required -- one for each partitioned table
* and each partition on each side (fortunately, not one for every combination
* thereof). We also need action triggers on each leaf partition on the
* referenced side, and check triggers on each leaf partition on the
* referencing side.
*/
static ObjectAddress
ATAddForeignKeyConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
Constraint *fkconstraint, Oid parentConstr,
bool recurse, bool recursing, LOCKMODE lockmode)
{
Relation pkrel;
int16 pkattnum[INDEX_MAX_KEYS];
int16 fkattnum[INDEX_MAX_KEYS];
Oid pktypoid[INDEX_MAX_KEYS];
Oid fktypoid[INDEX_MAX_KEYS];
Oid opclasses[INDEX_MAX_KEYS];
Oid pfeqoperators[INDEX_MAX_KEYS];
Oid ppeqoperators[INDEX_MAX_KEYS];
Oid ffeqoperators[INDEX_MAX_KEYS];
int i;
int numfks,
numpks;
Oid indexOid;
bool old_check_ok;
ObjectAddress address;
ListCell *old_pfeqop_item = list_head(fkconstraint->old_conpfeqop);
/*
* Grab ShareRowExclusiveLock on the pk table, so that someone doesn't
* delete rows out from under us.
*/
if (OidIsValid(fkconstraint->old_pktable_oid))
pkrel = table_open(fkconstraint->old_pktable_oid, ShareRowExclusiveLock);
else
pkrel = table_openrv(fkconstraint->pktable, ShareRowExclusiveLock);
/*
* Validity checks (permission checks wait till we have the column
* numbers)
*/
if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
{
if (!recurse)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot use ONLY for foreign key on partitioned table \"%s\" referencing relation \"%s\"",
RelationGetRelationName(rel),
RelationGetRelationName(pkrel))));
if (fkconstraint->skip_validation && !fkconstraint->initially_valid)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot add NOT VALID foreign key on partitioned table \"%s\" referencing relation \"%s\"",
RelationGetRelationName(rel),
RelationGetRelationName(pkrel)),
errdetail("This feature is not yet supported on partitioned tables.")));
}
if (pkrel->rd_rel->relkind != RELKIND_RELATION &&
pkrel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("referenced relation \"%s\" is not a table",
RelationGetRelationName(pkrel))));
if (!allowSystemTableMods && IsSystemRelation(pkrel))
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("permission denied: \"%s\" is a system catalog",
RelationGetRelationName(pkrel))));
/*
* References from permanent or unlogged tables to temp tables, and from
* permanent tables to unlogged tables, are disallowed because the
* referenced data can vanish out from under us. References from temp
* tables to any other table type are also disallowed, because other
* backends might need to run the RI triggers on the perm table, but they
* can't reliably see tuples in the local buffers of other backends.
*/
switch (rel->rd_rel->relpersistence)
{
case RELPERSISTENCE_PERMANENT:
if (pkrel->rd_rel->relpersistence != RELPERSISTENCE_PERMANENT)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("constraints on permanent tables may reference only permanent tables")));
break;
case RELPERSISTENCE_UNLOGGED:
if (pkrel->rd_rel->relpersistence != RELPERSISTENCE_PERMANENT
&& pkrel->rd_rel->relpersistence != RELPERSISTENCE_UNLOGGED)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("constraints on unlogged tables may reference only permanent or unlogged tables")));
break;
case RELPERSISTENCE_TEMP:
if (pkrel->rd_rel->relpersistence != RELPERSISTENCE_TEMP)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("constraints on temporary tables may reference only temporary tables")));
if (!pkrel->rd_islocaltemp || !rel->rd_islocaltemp)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("constraints on temporary tables must involve temporary tables of this session")));
break;
}
/*
* Look up the referencing attributes to make sure they exist, and record
* their attnums and type OIDs.
*/
MemSet(pkattnum, 0, sizeof(pkattnum));
MemSet(fkattnum, 0, sizeof(fkattnum));
MemSet(pktypoid, 0, sizeof(pktypoid));
MemSet(fktypoid, 0, sizeof(fktypoid));
MemSet(opclasses, 0, sizeof(opclasses));
MemSet(pfeqoperators, 0, sizeof(pfeqoperators));
MemSet(ppeqoperators, 0, sizeof(ppeqoperators));
MemSet(ffeqoperators, 0, sizeof(ffeqoperators));
numfks = transformColumnNameList(RelationGetRelid(rel),
fkconstraint->fk_attrs,
fkattnum, fktypoid);
/*
* If the attribute list for the referenced table was omitted, lookup the
* definition of the primary key and use it. Otherwise, validate the
* supplied attribute list. In either case, discover the index OID and
* index opclasses, and the attnums and type OIDs of the attributes.
*/
if (fkconstraint->pk_attrs == NIL)
{
numpks = transformFkeyGetPrimaryKey(pkrel, &indexOid,
&fkconstraint->pk_attrs,
pkattnum, pktypoid,
opclasses);
}
else
{
numpks = transformColumnNameList(RelationGetRelid(pkrel),
fkconstraint->pk_attrs,
pkattnum, pktypoid);
/* Look for an index matching the column list */
indexOid = transformFkeyCheckAttrs(pkrel, numpks, pkattnum,
opclasses);
}
/*
* Now we can check permissions.
*/
checkFkeyPermissions(pkrel, pkattnum, numpks);
/*
* Check some things for generated columns.
*/
for (i = 0; i < numfks; i++)
{
char attgenerated = TupleDescAttr(RelationGetDescr(rel), fkattnum[i] - 1)->attgenerated;
if (attgenerated)
{
/*
* Check restrictions on UPDATE/DELETE actions, per SQL standard
*/
if (fkconstraint->fk_upd_action == FKCONSTR_ACTION_SETNULL ||
fkconstraint->fk_upd_action == FKCONSTR_ACTION_SETDEFAULT ||
fkconstraint->fk_upd_action == FKCONSTR_ACTION_CASCADE)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("invalid %s action for foreign key constraint containing generated column",
"ON UPDATE")));
if (fkconstraint->fk_del_action == FKCONSTR_ACTION_SETNULL ||
fkconstraint->fk_del_action == FKCONSTR_ACTION_SETDEFAULT)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("invalid %s action for foreign key constraint containing generated column",
"ON DELETE")));
}
}
/*
* Look up the equality operators to use in the constraint.
*
* Note that we have to be careful about the difference between the actual
* PK column type and the opclass' declared input type, which might be
* only binary-compatible with it. The declared opcintype is the right
* thing to probe pg_amop with.
*/
if (numfks != numpks)
ereport(ERROR,
(errcode(ERRCODE_INVALID_FOREIGN_KEY),
errmsg("number of referencing and referenced columns for foreign key disagree")));
/*
* On the strength of a previous constraint, we might avoid scanning
* tables to validate this one. See below.
*/
old_check_ok = (fkconstraint->old_conpfeqop != NIL);
Assert(!old_check_ok || numfks == list_length(fkconstraint->old_conpfeqop));
for (i = 0; i < numpks; i++)
{
Oid pktype = pktypoid[i];
Oid fktype = fktypoid[i];
Oid fktyped;
HeapTuple cla_ht;
Form_pg_opclass cla_tup;
Oid amid;
Oid opfamily;
Oid opcintype;
Oid pfeqop;
Oid ppeqop;
Oid ffeqop;
int16 eqstrategy;
Oid pfeqop_right;
/* We need several fields out of the pg_opclass entry */
cla_ht = SearchSysCache1(CLAOID, ObjectIdGetDatum(opclasses[i]));
if (!HeapTupleIsValid(cla_ht))
elog(ERROR, "cache lookup failed for opclass %u", opclasses[i]);
cla_tup = (Form_pg_opclass) GETSTRUCT(cla_ht);
amid = cla_tup->opcmethod;
opfamily = cla_tup->opcfamily;
opcintype = cla_tup->opcintype;
ReleaseSysCache(cla_ht);
/*
* Check it's a btree; currently this can never fail since no other
* index AMs support unique indexes. If we ever did have other types
* of unique indexes, we'd need a way to determine which operator
* strategy number is equality. (Is it reasonable to insist that
* every such index AM use btree's number for equality?)
*/
if (amid != BTREE_AM_OID)
elog(ERROR, "only b-tree indexes are supported for foreign keys");
eqstrategy = BTEqualStrategyNumber;
/*
* There had better be a primary equality operator for the index.
* We'll use it for PK = PK comparisons.
*/
ppeqop = get_opfamily_member(opfamily, opcintype, opcintype,
eqstrategy);
if (!OidIsValid(ppeqop))
elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
eqstrategy, opcintype, opcintype, opfamily);
/*
* Are there equality operators that take exactly the FK type? Assume
* we should look through any domain here.
*/
fktyped = getBaseType(fktype);
pfeqop = get_opfamily_member(opfamily, opcintype, fktyped,
eqstrategy);
if (OidIsValid(pfeqop))
{
pfeqop_right = fktyped;
ffeqop = get_opfamily_member(opfamily, fktyped, fktyped,
eqstrategy);
}
else
{
/* keep compiler quiet */
pfeqop_right = InvalidOid;
ffeqop = InvalidOid;
}
if (!(OidIsValid(pfeqop) && OidIsValid(ffeqop)))
{
/*
* Otherwise, look for an implicit cast from the FK type to the
* opcintype, and if found, use the primary equality operator.
* This is a bit tricky because opcintype might be a polymorphic
* type such as ANYARRAY or ANYENUM; so what we have to test is
* whether the two actual column types can be concurrently cast to
* that type. (Otherwise, we'd fail to reject combinations such
* as int[] and point[].)
*/
Oid input_typeids[2];
Oid target_typeids[2];
input_typeids[0] = pktype;
input_typeids[1] = fktype;
target_typeids[0] = opcintype;
target_typeids[1] = opcintype;
if (can_coerce_type(2, input_typeids, target_typeids,
COERCION_IMPLICIT))
{
pfeqop = ffeqop = ppeqop;
pfeqop_right = opcintype;
}
}
if (!(OidIsValid(pfeqop) && OidIsValid(ffeqop)))
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("foreign key constraint \"%s\" cannot be implemented",
fkconstraint->conname),
errdetail("Key columns \"%s\" and \"%s\" "
"are of incompatible types: %s and %s.",
strVal(list_nth(fkconstraint->fk_attrs, i)),
strVal(list_nth(fkconstraint->pk_attrs, i)),
format_type_be(fktype),
format_type_be(pktype))));
if (old_check_ok)
{
/*
* When a pfeqop changes, revalidate the constraint. We could
* permit intra-opfamily changes, but that adds subtle complexity
* without any concrete benefit for core types. We need not
* assess ppeqop or ffeqop, which RI_Initial_Check() does not use.
*/
old_check_ok = (pfeqop == lfirst_oid(old_pfeqop_item));
old_pfeqop_item = lnext(fkconstraint->old_conpfeqop,
old_pfeqop_item);
}
if (old_check_ok)
{
Oid old_fktype;
Oid new_fktype;
CoercionPathType old_pathtype;
CoercionPathType new_pathtype;
Oid old_castfunc;
Oid new_castfunc;
Form_pg_attribute attr = TupleDescAttr(tab->oldDesc,
fkattnum[i] - 1);
/*
* Identify coercion pathways from each of the old and new FK-side
* column types to the right (foreign) operand type of the pfeqop.
* We may assume that pg_constraint.conkey is not changing.
*/
old_fktype = attr->atttypid;
new_fktype = fktype;
old_pathtype = findFkeyCast(pfeqop_right, old_fktype,
&old_castfunc);
new_pathtype = findFkeyCast(pfeqop_right, new_fktype,
&new_castfunc);
/*
* Upon a change to the cast from the FK column to its pfeqop
* operand, revalidate the constraint. For this evaluation, a
* binary coercion cast is equivalent to no cast at all. While
* type implementors should design implicit casts with an eye
* toward consistency of operations like equality, we cannot
* assume here that they have done so.
*
* A function with a polymorphic argument could change behavior
* arbitrarily in response to get_fn_expr_argtype(). Therefore,
* when the cast destination is polymorphic, we only avoid
* revalidation if the input type has not changed at all. Given
* just the core data types and operator classes, this requirement
* prevents no would-be optimizations.
*
* If the cast converts from a base type to a domain thereon, then
* that domain type must be the opcintype of the unique index.
* Necessarily, the primary key column must then be of the domain
* type. Since the constraint was previously valid, all values on
* the foreign side necessarily exist on the primary side and in
* turn conform to the domain. Consequently, we need not treat
* domains specially here.
*
* Since we require that all collations share the same notion of
* equality (which they do, because texteq reduces to bitwise
* equality), we don't compare collation here.
*
* We need not directly consider the PK type. It's necessarily
* binary coercible to the opcintype of the unique index column,
* and ri_triggers.c will only deal with PK datums in terms of
* that opcintype. Changing the opcintype also changes pfeqop.
*/
old_check_ok = (new_pathtype == old_pathtype &&
new_castfunc == old_castfunc &&
(!IsPolymorphicType(pfeqop_right) ||
new_fktype == old_fktype));
}
pfeqoperators[i] = pfeqop;
ppeqoperators[i] = ppeqop;
ffeqoperators[i] = ffeqop;
}
/*
* Create all the constraint and trigger objects, recursing to partitions
* as necessary. First handle the referenced side.
*/
address = addFkRecurseReferenced(wqueue, fkconstraint, rel, pkrel,
indexOid,
InvalidOid, /* no parent constraint */
numfks,
pkattnum,
fkattnum,
pfeqoperators,
ppeqoperators,
ffeqoperators,
old_check_ok);
/* Now handle the referencing side. */
addFkRecurseReferencing(wqueue, fkconstraint, rel, pkrel,
indexOid,
address.objectId,
numfks,
pkattnum,
fkattnum,
pfeqoperators,
ppeqoperators,
ffeqoperators,
old_check_ok,
lockmode);
/*
* Done. Close pk table, but keep lock until we've committed.
*/
table_close(pkrel, NoLock);
return address;
}
/*
* addFkRecurseReferenced
* subroutine for ATAddForeignKeyConstraint; recurses on the referenced
* side of the constraint
*
* Create pg_constraint rows for the referenced side of the constraint,
* referencing the parent of the referencing side; also create action triggers
* on leaf partitions. If the table is partitioned, recurse to handle each
* partition.
*
* wqueue is the ALTER TABLE work queue; can be NULL when not running as part
* of an ALTER TABLE sequence.
* fkconstraint is the constraint being added.
* rel is the root referencing relation.
* pkrel is the referenced relation; might be a partition, if recursing.
* indexOid is the OID of the index (on pkrel) implementing this constraint.
* parentConstr is the OID of a parent constraint; InvalidOid if this is a
* top-level constraint.
* numfks is the number of columns in the foreign key
* pkattnum is the attnum array of referenced attributes.
* fkattnum is the attnum array of referencing attributes.
* pf/pp/ffeqoperators are OID array of operators between columns.
* old_check_ok signals that this constraint replaces an existing one that
* was already validated (thus this one doesn't need validation).
*/
static ObjectAddress
addFkRecurseReferenced(List **wqueue, Constraint *fkconstraint, Relation rel,
Relation pkrel, Oid indexOid, Oid parentConstr,
int numfks,
int16 *pkattnum, int16 *fkattnum, Oid *pfeqoperators,
Oid *ppeqoperators, Oid *ffeqoperators, bool old_check_ok)
{
ObjectAddress address;
Oid constrOid;
char *conname;
bool conislocal;
int coninhcount;
bool connoinherit;
/*
* Verify relkind for each referenced partition. At the top level, this
* is redundant with a previous check, but we need it when recursing.
*/
if (pkrel->rd_rel->relkind != RELKIND_RELATION &&
pkrel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("referenced relation \"%s\" is not a table",
RelationGetRelationName(pkrel))));
/*
* Caller supplies us with a constraint name; however, it may be used in
* this partition, so come up with a different one in that case.
*/
if (ConstraintNameIsUsed(CONSTRAINT_RELATION,
RelationGetRelid(rel),
fkconstraint->conname))
conname = ChooseConstraintName(RelationGetRelationName(rel),
ChooseForeignKeyConstraintNameAddition(fkconstraint->fk_attrs),
"fkey",
RelationGetNamespace(rel), NIL);
else
conname = fkconstraint->conname;
if (OidIsValid(parentConstr))
{
conislocal = false;
coninhcount = 1;
connoinherit = false;
}
else
{
conislocal = true;
coninhcount = 0;
/*
* always inherit for partitioned tables, never for legacy inheritance
*/
connoinherit = rel->rd_rel->relkind != RELKIND_PARTITIONED_TABLE;
}
/*
* Record the FK constraint in pg_constraint.
*/
constrOid = CreateConstraintEntry(conname,
RelationGetNamespace(rel),
CONSTRAINT_FOREIGN,
fkconstraint->deferrable,
fkconstraint->initdeferred,
fkconstraint->initially_valid,
parentConstr,
RelationGetRelid(rel),
fkattnum,
numfks,
numfks,
InvalidOid, /* not a domain constraint */
indexOid,
RelationGetRelid(pkrel),
pkattnum,
pfeqoperators,
ppeqoperators,
ffeqoperators,
numfks,
fkconstraint->fk_upd_action,
fkconstraint->fk_del_action,
fkconstraint->fk_matchtype,
NULL, /* no exclusion constraint */
NULL, /* no check constraint */
NULL,
conislocal, /* islocal */
coninhcount, /* inhcount */
connoinherit, /* conNoInherit */
false); /* is_internal */
ObjectAddressSet(address, ConstraintRelationId, constrOid);
/*
* Mark the child constraint as part of the parent constraint; it must not
* be dropped on its own. (This constraint is deleted when the partition
* is detached, but a special check needs to occur that the partition
* contains no referenced values.)
*/
if (OidIsValid(parentConstr))
{
ObjectAddress referenced;
ObjectAddressSet(referenced, ConstraintRelationId, parentConstr);
recordDependencyOn(&address, &referenced, DEPENDENCY_INTERNAL);
}
/* make new constraint visible, in case we add more */
CommandCounterIncrement();
/*
* If the referenced table is a plain relation, create the action triggers
* that enforce the constraint.
*/
if (pkrel->rd_rel->relkind == RELKIND_RELATION)
{
createForeignKeyActionTriggers(rel, RelationGetRelid(pkrel),
fkconstraint,
constrOid, indexOid);
}
/*
* If the referenced table is partitioned, recurse on ourselves to handle
* each partition. We need one pg_constraint row created for each
* partition in addition to the pg_constraint row for the parent table.
*/
if (pkrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
{
PartitionDesc pd = RelationGetPartitionDesc(pkrel);
for (int i = 0; i < pd->nparts; i++)
{
Relation partRel;
AttrNumber *map;
AttrNumber *mapped_pkattnum;
Oid partIndexId;
partRel = table_open(pd->oids[i], ShareRowExclusiveLock);
/*
* Map the attribute numbers in the referenced side of the FK
* definition to match the partition's column layout.
*/
map = convert_tuples_by_name_map_if_req(RelationGetDescr(partRel),
RelationGetDescr(pkrel));
if (map)
{
mapped_pkattnum = palloc(sizeof(AttrNumber) * numfks);
for (int j = 0; j < numfks; j++)
mapped_pkattnum[j] = map[pkattnum[j] - 1];
}
else
mapped_pkattnum = pkattnum;
/* do the deed */
partIndexId = index_get_partition(partRel, indexOid);
if (!OidIsValid(partIndexId))
elog(ERROR, "index for %u not found in partition %s",
indexOid, RelationGetRelationName(partRel));
addFkRecurseReferenced(wqueue, fkconstraint, rel, partRel,
partIndexId, constrOid, numfks,
mapped_pkattnum, fkattnum,
pfeqoperators, ppeqoperators, ffeqoperators,
old_check_ok);
/* Done -- clean up (but keep the lock) */
table_close(partRel, NoLock);
if (map)
{
pfree(mapped_pkattnum);
pfree(map);
}
}
}
return address;
}
/*
* addFkRecurseReferencing
* subroutine for ATAddForeignKeyConstraint and CloneFkReferencing
*
* If the referencing relation is a plain relation, create the necessary check
* triggers that implement the constraint, and set up for Phase 3 constraint
* verification. If the referencing relation is a partitioned table, then
* we create a pg_constraint row for it and recurse on this routine for each
* partition.
*
* We assume that the referenced relation is locked against concurrent
* deletions. If it's a partitioned relation, every partition must be so
* locked.
*
* wqueue is the ALTER TABLE work queue; can be NULL when not running as part
* of an ALTER TABLE sequence.
* fkconstraint is the constraint being added.
* rel is the referencing relation; might be a partition, if recursing.
* pkrel is the root referenced relation.
* indexOid is the OID of the index (on pkrel) implementing this constraint.
* parentConstr is the OID of the parent constraint (there is always one).
* numfks is the number of columns in the foreign key
* pkattnum is the attnum array of referenced attributes.
* fkattnum is the attnum array of referencing attributes.
* pf/pp/ffeqoperators are OID array of operators between columns.
* old_check_ok signals that this constraint replaces an existing one that
* was already validated (thus this one doesn't need validation).
* lockmode is the lockmode to acquire on partitions when recursing.
*/
static void
addFkRecurseReferencing(List **wqueue, Constraint *fkconstraint, Relation rel,
Relation pkrel, Oid indexOid, Oid parentConstr,
int numfks, int16 *pkattnum, int16 *fkattnum,
Oid *pfeqoperators, Oid *ppeqoperators, Oid *ffeqoperators,
bool old_check_ok, LOCKMODE lockmode)
{
AssertArg(OidIsValid(parentConstr));
if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("foreign key constraints are not supported on foreign tables")));
/*
* If the referencing relation is a plain table, add the check triggers to
* it and, if necessary, schedule it to be checked in Phase 3.
*
* If the relation is partitioned, drill down to do it to its partitions.
*/
if (rel->rd_rel->relkind == RELKIND_RELATION)
{
createForeignKeyCheckTriggers(RelationGetRelid(rel),
RelationGetRelid(pkrel),
fkconstraint,
parentConstr,
indexOid);
/*
* Tell Phase 3 to check that the constraint is satisfied by existing
* rows. We can skip this during table creation, when requested
* explicitly by specifying NOT VALID in an ADD FOREIGN KEY command,
* and when we're recreating a constraint following a SET DATA TYPE
* operation that did not impugn its validity.
*/
if (wqueue && !old_check_ok && !fkconstraint->skip_validation)
{
NewConstraint *newcon;
AlteredTableInfo *tab;
tab = ATGetQueueEntry(wqueue, rel);
newcon = (NewConstraint *) palloc0(sizeof(NewConstraint));
newcon->name = get_constraint_name(parentConstr);
newcon->contype = CONSTR_FOREIGN;
newcon->refrelid = RelationGetRelid(pkrel);
newcon->refindid = indexOid;
newcon->conid = parentConstr;
newcon->qual = (Node *) fkconstraint;
tab->constraints = lappend(tab->constraints, newcon);
}
}
else if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
{
PartitionDesc pd = RelationGetPartitionDesc(rel);
/*
* Recurse to take appropriate action on each partition; either we
* find an existing constraint to reparent to ours, or we create a new
* one.
*/
for (int i = 0; i < pd->nparts; i++)
{
Oid partitionId = pd->oids[i];
Relation partition = table_open(partitionId, lockmode);
List *partFKs;
AttrNumber *attmap;
AttrNumber mapped_fkattnum[INDEX_MAX_KEYS];
bool attached;
char *conname;
Oid constrOid;
ObjectAddress address,
referenced;
ListCell *cell;
CheckTableNotInUse(partition, "ALTER TABLE");
attmap = convert_tuples_by_name_map(RelationGetDescr(partition),
RelationGetDescr(rel));
for (int j = 0; j < numfks; j++)
mapped_fkattnum[j] = attmap[fkattnum[j] - 1];
/* Check whether an existing constraint can be repurposed */
partFKs = copyObject(RelationGetFKeyList(partition));
attached = false;
foreach(cell, partFKs)
{
ForeignKeyCacheInfo *fk;
fk = lfirst_node(ForeignKeyCacheInfo, cell);
if (tryAttachPartitionForeignKey(fk,
partitionId,
parentConstr,
numfks,
mapped_fkattnum,
pkattnum,
pfeqoperators))
{
attached = true;
break;
}
}
if (attached)
{
table_close(partition, NoLock);
continue;
}
/*
* No luck finding a good constraint to reuse; create our own.
*/
if (ConstraintNameIsUsed(CONSTRAINT_RELATION,
RelationGetRelid(partition),
fkconstraint->conname))
conname = ChooseConstraintName(RelationGetRelationName(partition),
ChooseForeignKeyConstraintNameAddition(fkconstraint->fk_attrs),
"fkey",
RelationGetNamespace(partition), NIL);
else
conname = fkconstraint->conname;
constrOid =
CreateConstraintEntry(conname,
RelationGetNamespace(partition),
CONSTRAINT_FOREIGN,
fkconstraint->deferrable,
fkconstraint->initdeferred,
fkconstraint->initially_valid,
parentConstr,
partitionId,
mapped_fkattnum,
numfks,
numfks,
InvalidOid,
indexOid,
RelationGetRelid(pkrel),
pkattnum,
pfeqoperators,
ppeqoperators,
ffeqoperators,
numfks,
fkconstraint->fk_upd_action,
fkconstraint->fk_del_action,
fkconstraint->fk_matchtype,
NULL,
NULL,
NULL,
false,
1,
false,
false);
/*
* Give this constraint partition-type dependencies on the parent
* constraint as well as the table.
*/
ObjectAddressSet(address, ConstraintRelationId, constrOid);
ObjectAddressSet(referenced, ConstraintRelationId, parentConstr);
recordDependencyOn(&address, &referenced, DEPENDENCY_PARTITION_PRI);
ObjectAddressSet(referenced, RelationRelationId, partitionId);
recordDependencyOn(&address, &referenced, DEPENDENCY_PARTITION_SEC);
/* Make all this visible before recursing */
CommandCounterIncrement();
/* call ourselves to finalize the creation and we're done */
addFkRecurseReferencing(wqueue, fkconstraint, partition, pkrel,
indexOid,
constrOid,
numfks,
pkattnum,
mapped_fkattnum,
pfeqoperators,
ppeqoperators,
ffeqoperators,
old_check_ok,
lockmode);
table_close(partition, NoLock);
}
}
}
/*
* CloneForeignKeyConstraints
* Clone foreign keys from a partitioned table to a newly acquired
* partition.
*
* partitionRel is a partition of parentRel, so we can be certain that it has
* the same columns with the same datatypes. The columns may be in different
* order, though.
*
* wqueue must be passed to set up phase 3 constraint checking, unless the
* referencing-side partition is known to be empty (such as in CREATE TABLE /
* PARTITION OF).
*/
static void
CloneForeignKeyConstraints(List **wqueue, Relation parentRel,
Relation partitionRel)
{
/* This only works for declarative partitioning */
Assert(parentRel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE);
/*
* Clone constraints for which the parent is on the referenced side.
*/
CloneFkReferenced(parentRel, partitionRel);
/*
* Now clone constraints where the parent is on the referencing side.
*/
CloneFkReferencing(wqueue, parentRel, partitionRel);
}
/*
* CloneFkReferenced
* Subroutine for CloneForeignKeyConstraints
*
* Find all the FKs that have the parent relation on the referenced side;
* clone those constraints to the given partition. This is to be called
* when the partition is being created or attached.
*
* This recurses to partitions, if the relation being attached is partitioned.
* Recursion is done by calling addFkRecurseReferenced.
*/
static void
CloneFkReferenced(Relation parentRel, Relation partitionRel)
{
Relation pg_constraint;
AttrNumber *attmap;
ListCell *cell;
SysScanDesc scan;
ScanKeyData key[2];
HeapTuple tuple;
List *clone = NIL;
/*
* Search for any constraints where this partition is in the referenced
* side. However, we must ignore any constraint whose parent constraint
* is also going to be cloned, to avoid duplicates. So do it in two
* steps: first construct the list of constraints to clone, then go over
* that list cloning those whose parents are not in the list. (We must
* not rely on the parent being seen first, since the catalog scan could
* return children first.)
*/
pg_constraint = table_open(ConstraintRelationId, RowShareLock);
ScanKeyInit(&key[0],
Anum_pg_constraint_confrelid, BTEqualStrategyNumber,
F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(parentRel)));
ScanKeyInit(&key[1],
Anum_pg_constraint_contype, BTEqualStrategyNumber,
F_CHAREQ, CharGetDatum(CONSTRAINT_FOREIGN));
/* This is a seqscan, as we don't have a usable index ... */
scan = systable_beginscan(pg_constraint, InvalidOid, true,
NULL, 2, key);
while ((tuple = systable_getnext(scan)) != NULL)
{
Form_pg_constraint constrForm = (Form_pg_constraint) GETSTRUCT(tuple);
/* Only try to clone the top-level constraint; skip child ones. */
if (constrForm->conparentid != InvalidOid)
continue;
clone = lappend_oid(clone, constrForm->oid);
}
systable_endscan(scan);
table_close(pg_constraint, RowShareLock);
attmap = convert_tuples_by_name_map(RelationGetDescr(partitionRel),
RelationGetDescr(parentRel));
foreach(cell, clone)
{
Oid constrOid = lfirst_oid(cell);
Form_pg_constraint constrForm;
Relation fkRel;
Oid indexOid;
Oid partIndexId;
int numfks;
AttrNumber conkey[INDEX_MAX_KEYS];
AttrNumber mapped_confkey[INDEX_MAX_KEYS];
AttrNumber confkey[INDEX_MAX_KEYS];
Oid conpfeqop[INDEX_MAX_KEYS];
Oid conppeqop[INDEX_MAX_KEYS];
Oid conffeqop[INDEX_MAX_KEYS];
Constraint *fkconstraint;
tuple = SearchSysCache1(CONSTROID, constrOid);
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for constraint %u", constrOid);
constrForm = (Form_pg_constraint) GETSTRUCT(tuple);
/*
* Because we're only expanding the key space at the referenced side,
* we don't need to prevent any operation in the referencing table, so
* AccessShareLock suffices (assumes that dropping the constraint
* acquires AEL).
*/
fkRel = table_open(constrForm->conrelid, AccessShareLock);
indexOid = constrForm->conindid;
DeconstructFkConstraintRow(tuple,
&numfks,
conkey,
confkey,
conpfeqop,
conppeqop,
conffeqop);
for (int i = 0; i < numfks; i++)
mapped_confkey[i] = attmap[confkey[i] - 1];
fkconstraint = makeNode(Constraint);
/* for now this is all we need */
fkconstraint->conname = NameStr(constrForm->conname);
fkconstraint->fk_upd_action = constrForm->confupdtype;
fkconstraint->fk_del_action = constrForm->confdeltype;
fkconstraint->deferrable = constrForm->condeferrable;
fkconstraint->initdeferred = constrForm->condeferred;
fkconstraint->initially_valid = true;
fkconstraint->fk_matchtype = constrForm->confmatchtype;
/* set up colnames that are used to generate the constraint name */
for (int i = 0; i < numfks; i++)
{
Form_pg_attribute att;
att = TupleDescAttr(RelationGetDescr(fkRel),
conkey[i] - 1);
fkconstraint->fk_attrs = lappend(fkconstraint->fk_attrs,
makeString(NameStr(att->attname)));
}
/*
* Add the new foreign key constraint pointing to the new partition.
* Because this new partition appears in the referenced side of the
* constraint, we don't need to set up for Phase 3 check.
*/
partIndexId = index_get_partition(partitionRel, indexOid);
if (!OidIsValid(partIndexId))
elog(ERROR, "index for %u not found in partition %s",
indexOid, RelationGetRelationName(partitionRel));
addFkRecurseReferenced(NULL,
fkconstraint,
fkRel,
partitionRel,
partIndexId,
constrOid,
numfks,
mapped_confkey,
conkey,
conpfeqop,
conppeqop,
conffeqop,
true);
table_close(fkRel, NoLock);
ReleaseSysCache(tuple);
}
}
/*
* CloneFkReferencing
* Subroutine for CloneForeignKeyConstraints
*
* For each FK constraint of the parent relation in the given list, find an
* equivalent constraint in its partition relation that can be reparented;
* if one cannot be found, create a new constraint in the partition as its
* child.
*
* If wqueue is given, it is used to set up phase-3 verification for each
* cloned constraint; if omitted, we assume that such verification is not
* needed (example: the partition is being created anew).
*/
static void
CloneFkReferencing(List **wqueue, Relation parentRel, Relation partRel)
{
AttrNumber *attmap;
List *partFKs;
List *clone = NIL;
ListCell *cell;
/* obtain a list of constraints that we need to clone */
foreach(cell, RelationGetFKeyList(parentRel))
{
ForeignKeyCacheInfo *fk = lfirst(cell);
clone = lappend_oid(clone, fk->conoid);
}
/*
* Silently do nothing if there's nothing to do. In particular, this
* avoids throwing a spurious error for foreign tables.
*/
if (clone == NIL)
return;
if (partRel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("foreign key constraints are not supported on foreign tables")));
/*
* The constraint key may differ, if the columns in the partition are
* different. This map is used to convert them.
*/
attmap = convert_tuples_by_name_map(RelationGetDescr(partRel),
RelationGetDescr(parentRel));
partFKs = copyObject(RelationGetFKeyList(partRel));
foreach(cell, clone)
{
Oid parentConstrOid = lfirst_oid(cell);
Form_pg_constraint constrForm;
Relation pkrel;
HeapTuple tuple;
int numfks;
AttrNumber conkey[INDEX_MAX_KEYS];
AttrNumber mapped_conkey[INDEX_MAX_KEYS];
AttrNumber confkey[INDEX_MAX_KEYS];
Oid conpfeqop[INDEX_MAX_KEYS];
Oid conppeqop[INDEX_MAX_KEYS];
Oid conffeqop[INDEX_MAX_KEYS];
Constraint *fkconstraint;
bool attached;
Oid indexOid;
Oid constrOid;
ObjectAddress address,
referenced;
ListCell *cell;
tuple = SearchSysCache1(CONSTROID, parentConstrOid);
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for constraint %u",
parentConstrOid);
constrForm = (Form_pg_constraint) GETSTRUCT(tuple);
/* Don't clone constraints whose parents are being cloned */
if (list_member_oid(clone, constrForm->conparentid))
{
ReleaseSysCache(tuple);
continue;
}
/*
* Need to prevent concurrent deletions. If pkrel is a partitioned
* relation, that means to lock all partitions.
*/
pkrel = table_open(constrForm->confrelid, ShareRowExclusiveLock);
if (pkrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
(void) find_all_inheritors(RelationGetRelid(pkrel),
ShareRowExclusiveLock, NULL);
DeconstructFkConstraintRow(tuple, &numfks, conkey, confkey,
conpfeqop, conppeqop, conffeqop);
for (int i = 0; i < numfks; i++)
mapped_conkey[i] = attmap[conkey[i] - 1];
/*
* Before creating a new constraint, see whether any existing FKs are
* fit for the purpose. If one is, attach the parent constraint to
* it, and don't clone anything. This way we avoid the expensive
* verification step and don't end up with a duplicate FK, and we
* don't need to recurse to partitions for this constraint.
*/
attached = false;
foreach(cell, partFKs)
{
ForeignKeyCacheInfo *fk = lfirst_node(ForeignKeyCacheInfo, cell);
if (tryAttachPartitionForeignKey(fk,
RelationGetRelid(partRel),
parentConstrOid,
numfks,
mapped_conkey,
confkey,
conpfeqop))
{
attached = true;
table_close(pkrel, NoLock);
break;
}
}
if (attached)
{
ReleaseSysCache(tuple);
continue;
}
/* No dice. Set up to create our own constraint */
fkconstraint = makeNode(Constraint);
if (ConstraintNameIsUsed(CONSTRAINT_RELATION,
RelationGetRelid(partRel),
NameStr(constrForm->conname)))
fkconstraint->conname =
ChooseConstraintName(RelationGetRelationName(partRel),
ChooseForeignKeyConstraintNameAddition(fkconstraint->fk_attrs),
"fkey",
RelationGetNamespace(partRel), NIL);
else
fkconstraint->conname = pstrdup(NameStr(constrForm->conname));
fkconstraint->fk_upd_action = constrForm->confupdtype;
fkconstraint->fk_del_action = constrForm->confdeltype;
fkconstraint->deferrable = constrForm->condeferrable;
fkconstraint->initdeferred = constrForm->condeferred;
fkconstraint->fk_matchtype = constrForm->confmatchtype;
for (int i = 0; i < numfks; i++)
{
Form_pg_attribute att;
att = TupleDescAttr(RelationGetDescr(partRel),
mapped_conkey[i] - 1);
fkconstraint->fk_attrs = lappend(fkconstraint->fk_attrs,
makeString(NameStr(att->attname)));
}
indexOid = constrForm->conindid;
constrOid =
CreateConstraintEntry(fkconstraint->conname,
constrForm->connamespace,
CONSTRAINT_FOREIGN,
fkconstraint->deferrable,
fkconstraint->initdeferred,
constrForm->convalidated,
parentConstrOid,
RelationGetRelid(partRel),
mapped_conkey,
numfks,
numfks,
InvalidOid, /* not a domain constraint */
indexOid,
constrForm->confrelid, /* same foreign rel */
confkey,
conpfeqop,
conppeqop,
conffeqop,
numfks,
fkconstraint->fk_upd_action,
fkconstraint->fk_del_action,
fkconstraint->fk_matchtype,
NULL,
NULL,
NULL,
false, /* islocal */
1, /* inhcount */
false, /* conNoInherit */
true);
/* Set up partition dependencies for the new constraint */
ObjectAddressSet(address, ConstraintRelationId, constrOid);
ObjectAddressSet(referenced, ConstraintRelationId, parentConstrOid);
recordDependencyOn(&address, &referenced, DEPENDENCY_PARTITION_PRI);
ObjectAddressSet(referenced, RelationRelationId,
RelationGetRelid(partRel));
recordDependencyOn(&address, &referenced, DEPENDENCY_PARTITION_SEC);
/* Done with the cloned constraint's tuple */
ReleaseSysCache(tuple);
/* Make all this visible before recursing */
CommandCounterIncrement();
addFkRecurseReferencing(wqueue,
fkconstraint,
partRel,
pkrel,
indexOid,
constrOid,
numfks,
confkey,
mapped_conkey,
conpfeqop,
conppeqop,
conffeqop,
false, /* no old check exists */
AccessExclusiveLock);
table_close(pkrel, NoLock);
}
}
/*
* When the parent of a partition receives [the referencing side of] a foreign
* key, we must propagate that foreign key to the partition. However, the
* partition might already have an equivalent foreign key; this routine
* compares the given ForeignKeyCacheInfo (in the partition) to the FK defined
* by the other parameters. If they are equivalent, create the link between
* the two constraints and return true.
*
* If the given FK does not match the one defined by rest of the params,
* return false.
*/
static bool
tryAttachPartitionForeignKey(ForeignKeyCacheInfo *fk,
Oid partRelid,
Oid parentConstrOid,
int numfks,
AttrNumber *mapped_conkey,
AttrNumber *confkey,
Oid *conpfeqop)
{
HeapTuple parentConstrTup;
Form_pg_constraint parentConstr;
HeapTuple partcontup;
Form_pg_constraint partConstr;
Relation trigrel;
ScanKeyData key;
SysScanDesc scan;
HeapTuple trigtup;
parentConstrTup = SearchSysCache1(CONSTROID,
ObjectIdGetDatum(parentConstrOid));
if (!HeapTupleIsValid(parentConstrTup))
elog(ERROR, "cache lookup failed for constraint %u", parentConstrOid);
parentConstr = (Form_pg_constraint) GETSTRUCT(parentConstrTup);
/*
* Do some quick & easy initial checks. If any of these fail, we cannot
* use this constraint.
*/
if (fk->confrelid != parentConstr->confrelid || fk->nkeys != numfks)
{
ReleaseSysCache(parentConstrTup);
return false;
}
for (int i = 0; i < numfks; i++)
{
if (fk->conkey[i] != mapped_conkey[i] ||
fk->confkey[i] != confkey[i] ||
fk->conpfeqop[i] != conpfeqop[i])
{
ReleaseSysCache(parentConstrTup);
return false;
}
}
/*
* Looks good so far; do some more extensive checks. Presumably the check
* for 'convalidated' could be dropped, since we don't really care about
* that, but let's be careful for now.
*/
partcontup = SearchSysCache1(CONSTROID,
ObjectIdGetDatum(fk->conoid));
if (!HeapTupleIsValid(partcontup))
elog(ERROR, "cache lookup failed for constraint %u", fk->conoid);
partConstr = (Form_pg_constraint) GETSTRUCT(partcontup);
if (OidIsValid(partConstr->conparentid) ||
!partConstr->convalidated ||
partConstr->condeferrable != parentConstr->condeferrable ||
partConstr->condeferred != parentConstr->condeferred ||
partConstr->confupdtype != parentConstr->confupdtype ||
partConstr->confdeltype != parentConstr->confdeltype ||
partConstr->confmatchtype != parentConstr->confmatchtype)
{
ReleaseSysCache(parentConstrTup);
ReleaseSysCache(partcontup);
return false;
}
ReleaseSysCache(partcontup);
ReleaseSysCache(parentConstrTup);
/*
* Looks good! Attach this constraint. The action triggers in the new
* partition become redundant -- the parent table already has equivalent
* ones, and those will be able to reach the partition. Remove the ones
* in the partition. We identify them because they have our constraint
* OID, as well as being on the referenced rel.
*/
trigrel = table_open(TriggerRelationId, RowExclusiveLock);
ScanKeyInit(&key,
Anum_pg_trigger_tgconstraint,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(fk->conoid));
scan = systable_beginscan(trigrel, TriggerConstraintIndexId, true,
NULL, 1, &key);
while ((trigtup = systable_getnext(scan)) != NULL)
{
Form_pg_trigger trgform = (Form_pg_trigger) GETSTRUCT(trigtup);
ObjectAddress trigger;
if (trgform->tgconstrrelid != fk->conrelid)
continue;
if (trgform->tgrelid != fk->confrelid)
continue;
/*
* The constraint is originally set up to contain this trigger as an
* implementation object, so there's a dependency record that links
* the two; however, since the trigger is no longer needed, we remove
* the dependency link in order to be able to drop the trigger while
* keeping the constraint intact.
*/
deleteDependencyRecordsFor(TriggerRelationId,
trgform->oid,
false);
/* make dependency deletion visible to performDeletion */
CommandCounterIncrement();
ObjectAddressSet(trigger, TriggerRelationId,
trgform->oid);
performDeletion(&trigger, DROP_RESTRICT, 0);
/* make trigger drop visible, in case the loop iterates */
CommandCounterIncrement();
}
systable_endscan(scan);
table_close(trigrel, RowExclusiveLock);
ConstraintSetParentConstraint(fk->conoid, parentConstrOid, partRelid);
CommandCounterIncrement();
return true;
}
/*
* ALTER TABLE ALTER CONSTRAINT
*
* Update the attributes of a constraint.
*
* Currently only works for Foreign Key constraints.
* Foreign keys do not inherit, so we purposely ignore the
* recursion bit here, but we keep the API the same for when
* other constraint types are supported.
*
* If the constraint is modified, returns its address; otherwise, return
* InvalidObjectAddress.
*/
static ObjectAddress
ATExecAlterConstraint(Relation rel, AlterTableCmd *cmd,
bool recurse, bool recursing, LOCKMODE lockmode)
{
Constraint *cmdcon;
Relation conrel;
SysScanDesc scan;
ScanKeyData skey[3];
HeapTuple contuple;
Form_pg_constraint currcon;
ObjectAddress address;
cmdcon = castNode(Constraint, cmd->def);
conrel = table_open(ConstraintRelationId, RowExclusiveLock);
/*
* Find and check the target constraint
*/
ScanKeyInit(&skey[0],
Anum_pg_constraint_conrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(rel)));
ScanKeyInit(&skey[1],
Anum_pg_constraint_contypid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(InvalidOid));
ScanKeyInit(&skey[2],
Anum_pg_constraint_conname,
BTEqualStrategyNumber, F_NAMEEQ,
CStringGetDatum(cmdcon->conname));
scan = systable_beginscan(conrel, ConstraintRelidTypidNameIndexId,
true, NULL, 3, skey);
/* There can be at most one matching row */
if (!HeapTupleIsValid(contuple = systable_getnext(scan)))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("constraint \"%s\" of relation \"%s\" does not exist",
cmdcon->conname, RelationGetRelationName(rel))));
currcon = (Form_pg_constraint) GETSTRUCT(contuple);
if (currcon->contype != CONSTRAINT_FOREIGN)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("constraint \"%s\" of relation \"%s\" is not a foreign key constraint",
cmdcon->conname, RelationGetRelationName(rel))));
if (currcon->condeferrable != cmdcon->deferrable ||
currcon->condeferred != cmdcon->initdeferred)
{
HeapTuple copyTuple;
HeapTuple tgtuple;
Form_pg_constraint copy_con;
List *otherrelids = NIL;
ScanKeyData tgkey;
SysScanDesc tgscan;
Relation tgrel;
ListCell *lc;
/*
* Now update the catalog, while we have the door open.
*/
copyTuple = heap_copytuple(contuple);
copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple);
copy_con->condeferrable = cmdcon->deferrable;
copy_con->condeferred = cmdcon->initdeferred;
CatalogTupleUpdate(conrel, &copyTuple->t_self, copyTuple);
InvokeObjectPostAlterHook(ConstraintRelationId,
currcon->oid, 0);
heap_freetuple(copyTuple);
/*
* Now we need to update the multiple entries in pg_trigger that
* implement the constraint.
*/
tgrel = table_open(TriggerRelationId, RowExclusiveLock);
ScanKeyInit(&tgkey,
Anum_pg_trigger_tgconstraint,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(currcon->oid));
tgscan = systable_beginscan(tgrel, TriggerConstraintIndexId, true,
NULL, 1, &tgkey);
while (HeapTupleIsValid(tgtuple = systable_getnext(tgscan)))
{
Form_pg_trigger tgform = (Form_pg_trigger) GETSTRUCT(tgtuple);
Form_pg_trigger copy_tg;
/*
* Remember OIDs of other relation(s) involved in FK constraint.
* (Note: it's likely that we could skip forcing a relcache inval
* for other rels that don't have a trigger whose properties
* change, but let's be conservative.)
*/
if (tgform->tgrelid != RelationGetRelid(rel))
otherrelids = list_append_unique_oid(otherrelids,
tgform->tgrelid);
/*
* Update deferrability of RI_FKey_noaction_del,
* RI_FKey_noaction_upd, RI_FKey_check_ins and RI_FKey_check_upd
* triggers, but not others; see createForeignKeyActionTriggers
* and CreateFKCheckTrigger.
*/
if (tgform->tgfoid != F_RI_FKEY_NOACTION_DEL &&
tgform->tgfoid != F_RI_FKEY_NOACTION_UPD &&
tgform->tgfoid != F_RI_FKEY_CHECK_INS &&
tgform->tgfoid != F_RI_FKEY_CHECK_UPD)
continue;
copyTuple = heap_copytuple(tgtuple);
copy_tg = (Form_pg_trigger) GETSTRUCT(copyTuple);
copy_tg->tgdeferrable = cmdcon->deferrable;
copy_tg->tginitdeferred = cmdcon->initdeferred;
CatalogTupleUpdate(tgrel, &copyTuple->t_self, copyTuple);
InvokeObjectPostAlterHook(TriggerRelationId, currcon->oid, 0);
heap_freetuple(copyTuple);
}
systable_endscan(tgscan);
table_close(tgrel, RowExclusiveLock);
/*
* Invalidate relcache so that others see the new attributes. We must
* inval both the named rel and any others having relevant triggers.
* (At present there should always be exactly one other rel, but
* there's no need to hard-wire such an assumption here.)
*/
CacheInvalidateRelcache(rel);
foreach(lc, otherrelids)
{
CacheInvalidateRelcacheByRelid(lfirst_oid(lc));
}
ObjectAddressSet(address, ConstraintRelationId, currcon->oid);
}
else
address = InvalidObjectAddress;
systable_endscan(scan);
table_close(conrel, RowExclusiveLock);
return address;
}
/*
* ALTER TABLE VALIDATE CONSTRAINT
*
* XXX The reason we handle recursion here rather than at Phase 1 is because
* there's no good way to skip recursing when handling foreign keys: there is
* no need to lock children in that case, yet we wouldn't be able to avoid
* doing so at that level.
*
* Return value is the address of the validated constraint. If the constraint
* was already validated, InvalidObjectAddress is returned.
*/
static ObjectAddress
ATExecValidateConstraint(Relation rel, char *constrName, bool recurse,
bool recursing, LOCKMODE lockmode)
{
Relation conrel;
SysScanDesc scan;
ScanKeyData skey[3];
HeapTuple tuple;
Form_pg_constraint con;
ObjectAddress address;
conrel = table_open(ConstraintRelationId, RowExclusiveLock);
/*
* Find and check the target constraint
*/
ScanKeyInit(&skey[0],
Anum_pg_constraint_conrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(rel)));
ScanKeyInit(&skey[1],
Anum_pg_constraint_contypid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(InvalidOid));
ScanKeyInit(&skey[2],
Anum_pg_constraint_conname,
BTEqualStrategyNumber, F_NAMEEQ,
CStringGetDatum(constrName));
scan = systable_beginscan(conrel, ConstraintRelidTypidNameIndexId,
true, NULL, 3, skey);
/* There can be at most one matching row */
if (!HeapTupleIsValid(tuple = systable_getnext(scan)))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("constraint \"%s\" of relation \"%s\" does not exist",
constrName, RelationGetRelationName(rel))));
con = (Form_pg_constraint) GETSTRUCT(tuple);
if (con->contype != CONSTRAINT_FOREIGN &&
con->contype != CONSTRAINT_CHECK)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("constraint \"%s\" of relation \"%s\" is not a foreign key or check constraint",
constrName, RelationGetRelationName(rel))));
if (!con->convalidated)
{
HeapTuple copyTuple;
Form_pg_constraint copy_con;
if (con->contype == CONSTRAINT_FOREIGN)
{
Relation refrel;
/*
* Triggers are already in place on both tables, so a concurrent
* write that alters the result here is not possible. Normally we
* can run a query here to do the validation, which would only
* require AccessShareLock. In some cases, it is possible that we
* might need to fire triggers to perform the check, so we take a
* lock at RowShareLock level just in case.
*/
refrel = table_open(con->confrelid, RowShareLock);
validateForeignKeyConstraint(constrName, rel, refrel,
con->conindid,
con->oid);
table_close(refrel, NoLock);
/*
* We disallow creating invalid foreign keys to or from
* partitioned tables, so ignoring the recursion bit is okay.
*/
}
else if (con->contype == CONSTRAINT_CHECK)
{
List *children = NIL;
ListCell *child;
/*
* If we're recursing, the parent has already done this, so skip
* it. Also, if the constraint is a NO INHERIT constraint, we
* shouldn't try to look for it in the children.
*/
if (!recursing && !con->connoinherit)
children = find_all_inheritors(RelationGetRelid(rel),
lockmode, NULL);
/*
* For CHECK constraints, we must ensure that we only mark the
* constraint as validated on the parent if it's already validated
* on the children.
*
* We recurse before validating on the parent, to reduce risk of
* deadlocks.
*/
foreach(child, children)
{
Oid childoid = lfirst_oid(child);
Relation childrel;
if (childoid == RelationGetRelid(rel))
continue;
/*
* If we are told not to recurse, there had better not be any
* child tables, because we can't mark the constraint on the
* parent valid unless it is valid for all child tables.
*/
if (!recurse)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("constraint must be validated on child tables too")));
/* find_all_inheritors already got lock */
childrel = table_open(childoid, NoLock);
ATExecValidateConstraint(childrel, constrName, false,
true, lockmode);
table_close(childrel, NoLock);
}
validateCheckConstraint(rel, tuple);
/*
* Invalidate relcache so that others see the new validated
* constraint.
*/
CacheInvalidateRelcache(rel);
}
/*
* Now update the catalog, while we have the door open.
*/
copyTuple = heap_copytuple(tuple);
copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple);
copy_con->convalidated = true;
CatalogTupleUpdate(conrel, &copyTuple->t_self, copyTuple);
InvokeObjectPostAlterHook(ConstraintRelationId, con->oid, 0);
heap_freetuple(copyTuple);
ObjectAddressSet(address, ConstraintRelationId, con->oid);
}
else
address = InvalidObjectAddress; /* already validated */
systable_endscan(scan);
table_close(conrel, RowExclusiveLock);
return address;
}
/*
* transformColumnNameList - transform list of column names
*
* Lookup each name and return its attnum and type OID
*/
static int
transformColumnNameList(Oid relId, List *colList,
int16 *attnums, Oid *atttypids)
{
ListCell *l;
int attnum;
attnum = 0;
foreach(l, colList)
{
char *attname = strVal(lfirst(l));
HeapTuple atttuple;
atttuple = SearchSysCacheAttName(relId, attname);
if (!HeapTupleIsValid(atttuple))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" referenced in foreign key constraint does not exist",
attname)));
if (attnum >= INDEX_MAX_KEYS)
ereport(ERROR,
(errcode(ERRCODE_TOO_MANY_COLUMNS),
errmsg("cannot have more than %d keys in a foreign key",
INDEX_MAX_KEYS)));
attnums[attnum] = ((Form_pg_attribute) GETSTRUCT(atttuple))->attnum;
atttypids[attnum] = ((Form_pg_attribute) GETSTRUCT(atttuple))->atttypid;
ReleaseSysCache(atttuple);
attnum++;
}
return attnum;
}
/*
* transformFkeyGetPrimaryKey -
*
* Look up the names, attnums, and types of the primary key attributes
* for the pkrel. Also return the index OID and index opclasses of the
* index supporting the primary key.
*
* All parameters except pkrel are output parameters. Also, the function
* return value is the number of attributes in the primary key.
*
* Used when the column list in the REFERENCES specification is omitted.
*/
static int
transformFkeyGetPrimaryKey(Relation pkrel, Oid *indexOid,
List **attnamelist,
int16 *attnums, Oid *atttypids,
Oid *opclasses)
{
List *indexoidlist;
ListCell *indexoidscan;
HeapTuple indexTuple = NULL;
Form_pg_index indexStruct = NULL;
Datum indclassDatum;
bool isnull;
oidvector *indclass;
int i;
/*
* Get the list of index OIDs for the table from the relcache, and look up
* each one in the pg_index syscache until we find one marked primary key
* (hopefully there isn't more than one such). Insist it's valid, too.
*/
*indexOid = InvalidOid;
indexoidlist = RelationGetIndexList(pkrel);
foreach(indexoidscan, indexoidlist)
{
Oid indexoid = lfirst_oid(indexoidscan);
indexTuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexoid));
if (!HeapTupleIsValid(indexTuple))
elog(ERROR, "cache lookup failed for index %u", indexoid);
indexStruct = (Form_pg_index) GETSTRUCT(indexTuple);
if (indexStruct->indisprimary && indexStruct->indisvalid)
{
/*
* Refuse to use a deferrable primary key. This is per SQL spec,
* and there would be a lot of interesting semantic problems if we
* tried to allow it.
*/
if (!indexStruct->indimmediate)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("cannot use a deferrable primary key for referenced table \"%s\"",
RelationGetRelationName(pkrel))));
*indexOid = indexoid;
break;
}
ReleaseSysCache(indexTuple);
}
list_free(indexoidlist);
/*
* Check that we found it
*/
if (!OidIsValid(*indexOid))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("there is no primary key for referenced table \"%s\"",
RelationGetRelationName(pkrel))));
/* Must get indclass the hard way */
indclassDatum = SysCacheGetAttr(INDEXRELID, indexTuple,
Anum_pg_index_indclass, &isnull);
Assert(!isnull);
indclass = (oidvector *) DatumGetPointer(indclassDatum);
/*
* Now build the list of PK attributes from the indkey definition (we
* assume a primary key cannot have expressional elements)
*/
*attnamelist = NIL;
for (i = 0; i < indexStruct->indnkeyatts; i++)
{
int pkattno = indexStruct->indkey.values[i];
attnums[i] = pkattno;
atttypids[i] = attnumTypeId(pkrel, pkattno);
opclasses[i] = indclass->values[i];
*attnamelist = lappend(*attnamelist,
makeString(pstrdup(NameStr(*attnumAttName(pkrel, pkattno)))));
}
ReleaseSysCache(indexTuple);
return i;
}
/*
* transformFkeyCheckAttrs -
*
* Make sure that the attributes of a referenced table belong to a unique
* (or primary key) constraint. Return the OID of the index supporting
* the constraint, as well as the opclasses associated with the index
* columns.
*/
static Oid
transformFkeyCheckAttrs(Relation pkrel,
int numattrs, int16 *attnums,
Oid *opclasses) /* output parameter */
{
Oid indexoid = InvalidOid;
bool found = false;
bool found_deferrable = false;
List *indexoidlist;
ListCell *indexoidscan;
int i,
j;
/*
* Reject duplicate appearances of columns in the referenced-columns list.
* Such a case is forbidden by the SQL standard, and even if we thought it
* useful to allow it, there would be ambiguity about how to match the
* list to unique indexes (in particular, it'd be unclear which index
* opclass goes with which FK column).
*/
for (i = 0; i < numattrs; i++)
{
for (j = i + 1; j < numattrs; j++)
{
if (attnums[i] == attnums[j])
ereport(ERROR,
(errcode(ERRCODE_INVALID_FOREIGN_KEY),
errmsg("foreign key referenced-columns list must not contain duplicates")));
}
}
/*
* Get the list of index OIDs for the table from the relcache, and look up
* each one in the pg_index syscache, and match unique indexes to the list
* of attnums we are given.
*/
indexoidlist = RelationGetIndexList(pkrel);
foreach(indexoidscan, indexoidlist)
{
HeapTuple indexTuple;
Form_pg_index indexStruct;
indexoid = lfirst_oid(indexoidscan);
indexTuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexoid));
if (!HeapTupleIsValid(indexTuple))
elog(ERROR, "cache lookup failed for index %u", indexoid);
indexStruct = (Form_pg_index) GETSTRUCT(indexTuple);
/*
* Must have the right number of columns; must be unique and not a
* partial index; forget it if there are any expressions, too. Invalid
* indexes are out as well.
*/
if (indexStruct->indnkeyatts == numattrs &&
indexStruct->indisunique &&
indexStruct->indisvalid &&
heap_attisnull(indexTuple, Anum_pg_index_indpred, NULL) &&
heap_attisnull(indexTuple, Anum_pg_index_indexprs, NULL))
{
Datum indclassDatum;
bool isnull;
oidvector *indclass;
/* Must get indclass the hard way */
indclassDatum = SysCacheGetAttr(INDEXRELID, indexTuple,
Anum_pg_index_indclass, &isnull);
Assert(!isnull);
indclass = (oidvector *) DatumGetPointer(indclassDatum);
/*
* The given attnum list may match the index columns in any order.
* Check for a match, and extract the appropriate opclasses while
* we're at it.
*
* We know that attnums[] is duplicate-free per the test at the
* start of this function, and we checked above that the number of
* index columns agrees, so if we find a match for each attnums[]
* entry then we must have a one-to-one match in some order.
*/
for (i = 0; i < numattrs; i++)
{
found = false;
for (j = 0; j < numattrs; j++)
{
if (attnums[i] == indexStruct->indkey.values[j])
{
opclasses[i] = indclass->values[j];
found = true;
break;
}
}
if (!found)
break;
}
/*
* Refuse to use a deferrable unique/primary key. This is per SQL
* spec, and there would be a lot of interesting semantic problems
* if we tried to allow it.
*/
if (found && !indexStruct->indimmediate)
{
/*
* Remember that we found an otherwise matching index, so that
* we can generate a more appropriate error message.
*/
found_deferrable = true;
found = false;
}
}
ReleaseSysCache(indexTuple);
if (found)
break;
}
if (!found)
{
if (found_deferrable)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("cannot use a deferrable unique constraint for referenced table \"%s\"",
RelationGetRelationName(pkrel))));
else
ereport(ERROR,
(errcode(ERRCODE_INVALID_FOREIGN_KEY),
errmsg("there is no unique constraint matching given keys for referenced table \"%s\"",
RelationGetRelationName(pkrel))));
}
list_free(indexoidlist);
return indexoid;
}
/*
* findFkeyCast -
*
* Wrapper around find_coercion_pathway() for ATAddForeignKeyConstraint().
* Caller has equal regard for binary coercibility and for an exact match.
*/
static CoercionPathType
findFkeyCast(Oid targetTypeId, Oid sourceTypeId, Oid *funcid)
{
CoercionPathType ret;
if (targetTypeId == sourceTypeId)
{
ret = COERCION_PATH_RELABELTYPE;
*funcid = InvalidOid;
}
else
{
ret = find_coercion_pathway(targetTypeId, sourceTypeId,
COERCION_IMPLICIT, funcid);
if (ret == COERCION_PATH_NONE)
/* A previously-relied-upon cast is now gone. */
elog(ERROR, "could not find cast from %u to %u",
sourceTypeId, targetTypeId);
}
return ret;
}
/*
* Permissions checks on the referenced table for ADD FOREIGN KEY
*
* Note: we have already checked that the user owns the referencing table,
* else we'd have failed much earlier; no additional checks are needed for it.
*/
static void
checkFkeyPermissions(Relation rel, int16 *attnums, int natts)
{
Oid roleid = GetUserId();
AclResult aclresult;
int i;
/* Okay if we have relation-level REFERENCES permission */
aclresult = pg_class_aclcheck(RelationGetRelid(rel), roleid,
ACL_REFERENCES);
if (aclresult == ACLCHECK_OK)
return;
/* Else we must have REFERENCES on each column */
for (i = 0; i < natts; i++)
{
aclresult = pg_attribute_aclcheck(RelationGetRelid(rel), attnums[i],
roleid, ACL_REFERENCES);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, get_relkind_objtype(rel->rd_rel->relkind),
RelationGetRelationName(rel));
}
}
/*
* Scan the existing rows in a table to verify they meet a proposed
* CHECK constraint.
*
* The caller must have opened and locked the relation appropriately.
*/
static void
validateCheckConstraint(Relation rel, HeapTuple constrtup)
{
EState *estate;
Datum val;
char *conbin;
Expr *origexpr;
ExprState *exprstate;
TableScanDesc scan;
ExprContext *econtext;
MemoryContext oldcxt;
TupleTableSlot *slot;
Form_pg_constraint constrForm;
bool isnull;
Snapshot snapshot;
/*
* VALIDATE CONSTRAINT is a no-op for foreign tables and partitioned
* tables.
*/
if (rel->rd_rel->relkind == RELKIND_FOREIGN_TABLE ||
rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
return;
constrForm = (Form_pg_constraint) GETSTRUCT(constrtup);
estate = CreateExecutorState();
/*
* XXX this tuple doesn't really come from a syscache, but this doesn't
* matter to SysCacheGetAttr, because it only wants to be able to fetch
* the tupdesc
*/
val = SysCacheGetAttr(CONSTROID, constrtup, Anum_pg_constraint_conbin,
&isnull);
if (isnull)
elog(ERROR, "null conbin for constraint %u",
constrForm->oid);
conbin = TextDatumGetCString(val);
origexpr = (Expr *) stringToNode(conbin);
exprstate = ExecPrepareExpr(origexpr, estate);
econtext = GetPerTupleExprContext(estate);
slot = table_slot_create(rel, NULL);
econtext->ecxt_scantuple = slot;
snapshot = RegisterSnapshot(GetLatestSnapshot());
scan = table_beginscan(rel, snapshot, 0, NULL);
/*
* Switch to per-tuple memory context and reset it for each tuple
* produced, so we don't leak memory.
*/
oldcxt = MemoryContextSwitchTo(GetPerTupleMemoryContext(estate));
while (table_scan_getnextslot(scan, ForwardScanDirection, slot))
{
if (!ExecCheck(exprstate, econtext))
ereport(ERROR,
(errcode(ERRCODE_CHECK_VIOLATION),
errmsg("check constraint \"%s\" is violated by some row",
NameStr(constrForm->conname)),
errtableconstraint(rel, NameStr(constrForm->conname))));
ResetExprContext(econtext);
}
MemoryContextSwitchTo(oldcxt);
table_endscan(scan);
UnregisterSnapshot(snapshot);
ExecDropSingleTupleTableSlot(slot);
FreeExecutorState(estate);
}
/*
* Scan the existing rows in a table to verify they meet a proposed FK
* constraint.
*
* Caller must have opened and locked both relations appropriately.
*/
static void
validateForeignKeyConstraint(char *conname,
Relation rel,
Relation pkrel,
Oid pkindOid,
Oid constraintOid)
{
TupleTableSlot *slot;
TableScanDesc scan;
Trigger trig;
Snapshot snapshot;
MemoryContext oldcxt;
MemoryContext perTupCxt;
ereport(DEBUG1,
(errmsg("validating foreign key constraint \"%s\"", conname)));
/*
* Build a trigger call structure; we'll need it either way.
*/
MemSet(&trig, 0, sizeof(trig));
trig.tgoid = InvalidOid;
trig.tgname = conname;
trig.tgenabled = TRIGGER_FIRES_ON_ORIGIN;
trig.tgisinternal = true;
trig.tgconstrrelid = RelationGetRelid(pkrel);
trig.tgconstrindid = pkindOid;
trig.tgconstraint = constraintOid;
trig.tgdeferrable = false;
trig.tginitdeferred = false;
/* we needn't fill in remaining fields */
/*
* See if we can do it with a single LEFT JOIN query. A false result
* indicates we must proceed with the fire-the-trigger method.
*/
if (RI_Initial_Check(&trig, rel, pkrel))
return;
/*
* Scan through each tuple, calling RI_FKey_check_ins (insert trigger) as
* if that tuple had just been inserted. If any of those fail, it should
* ereport(ERROR) and that's that.
*/
snapshot = RegisterSnapshot(GetLatestSnapshot());
slot = table_slot_create(rel, NULL);
scan = table_beginscan(rel, snapshot, 0, NULL);
perTupCxt = AllocSetContextCreate(CurrentMemoryContext,
"validateForeignKeyConstraint",
ALLOCSET_SMALL_SIZES);
oldcxt = MemoryContextSwitchTo(perTupCxt);
while (table_scan_getnextslot(scan, ForwardScanDirection, slot))
{
LOCAL_FCINFO(fcinfo, 0);
TriggerData trigdata;
CHECK_FOR_INTERRUPTS();
/*
* Make a call to the trigger function
*
* No parameters are passed, but we do set a context
*/
MemSet(fcinfo, 0, SizeForFunctionCallInfo(0));
/*
* We assume RI_FKey_check_ins won't look at flinfo...
*/
trigdata.type = T_TriggerData;
trigdata.tg_event = TRIGGER_EVENT_INSERT | TRIGGER_EVENT_ROW;
trigdata.tg_relation = rel;
trigdata.tg_trigtuple = ExecFetchSlotHeapTuple(slot, false, NULL);
trigdata.tg_trigslot = slot;
trigdata.tg_newtuple = NULL;
trigdata.tg_newslot = NULL;
trigdata.tg_trigger = &trig;
fcinfo->context = (Node *) &trigdata;
RI_FKey_check_ins(fcinfo);
MemoryContextReset(perTupCxt);
}
MemoryContextSwitchTo(oldcxt);
MemoryContextDelete(perTupCxt);
table_endscan(scan);
UnregisterSnapshot(snapshot);
ExecDropSingleTupleTableSlot(slot);
}
static void
CreateFKCheckTrigger(Oid myRelOid, Oid refRelOid, Constraint *fkconstraint,
Oid constraintOid, Oid indexOid, bool on_insert)
{
CreateTrigStmt *fk_trigger;
/*
* Note: for a self-referential FK (referencing and referenced tables are
* the same), it is important that the ON UPDATE action fires before the
* CHECK action, since both triggers will fire on the same row during an
* UPDATE event; otherwise the CHECK trigger will be checking a non-final
* state of the row. Triggers fire in name order, so we ensure this by
* using names like "RI_ConstraintTrigger_a_NNNN" for the action triggers
* and "RI_ConstraintTrigger_c_NNNN" for the check triggers.
*/
fk_trigger = makeNode(CreateTrigStmt);
fk_trigger->trigname = "RI_ConstraintTrigger_c";
fk_trigger->relation = NULL;
fk_trigger->row = true;
fk_trigger->timing = TRIGGER_TYPE_AFTER;
/* Either ON INSERT or ON UPDATE */
if (on_insert)
{
fk_trigger->funcname = SystemFuncName("RI_FKey_check_ins");
fk_trigger->events = TRIGGER_TYPE_INSERT;
}
else
{
fk_trigger->funcname = SystemFuncName("RI_FKey_check_upd");
fk_trigger->events = TRIGGER_TYPE_UPDATE;
}
fk_trigger->columns = NIL;
fk_trigger->transitionRels = NIL;
fk_trigger->whenClause = NULL;
fk_trigger->isconstraint = true;
fk_trigger->deferrable = fkconstraint->deferrable;
fk_trigger->initdeferred = fkconstraint->initdeferred;
fk_trigger->constrrel = NULL;
fk_trigger->args = NIL;
(void) CreateTrigger(fk_trigger, NULL, myRelOid, refRelOid, constraintOid,
indexOid, InvalidOid, InvalidOid, NULL, true, false);
/* Make changes-so-far visible */
CommandCounterIncrement();
}
/*
* createForeignKeyActionTriggers
* Create the referenced-side "action" triggers that implement a foreign
* key.
*/
static void
createForeignKeyActionTriggers(Relation rel, Oid refRelOid, Constraint *fkconstraint,
Oid constraintOid, Oid indexOid)
{
CreateTrigStmt *fk_trigger;
/*
* Build and execute a CREATE CONSTRAINT TRIGGER statement for the ON
* DELETE action on the referenced table.
*/
fk_trigger = makeNode(CreateTrigStmt);
fk_trigger->trigname = "RI_ConstraintTrigger_a";
fk_trigger->relation = NULL;
fk_trigger->row = true;
fk_trigger->timing = TRIGGER_TYPE_AFTER;
fk_trigger->events = TRIGGER_TYPE_DELETE;
fk_trigger->columns = NIL;
fk_trigger->transitionRels = NIL;
fk_trigger->whenClause = NULL;
fk_trigger->isconstraint = true;
fk_trigger->constrrel = NULL;
switch (fkconstraint->fk_del_action)
{
case FKCONSTR_ACTION_NOACTION:
fk_trigger->deferrable = fkconstraint->deferrable;
fk_trigger->initdeferred = fkconstraint->initdeferred;
fk_trigger->funcname = SystemFuncName("RI_FKey_noaction_del");
break;
case FKCONSTR_ACTION_RESTRICT:
fk_trigger->deferrable = false;
fk_trigger->initdeferred = false;
fk_trigger->funcname = SystemFuncName("RI_FKey_restrict_del");
break;
case FKCONSTR_ACTION_CASCADE:
fk_trigger->deferrable = false;
fk_trigger->initdeferred = false;
fk_trigger->funcname = SystemFuncName("RI_FKey_cascade_del");
break;
case FKCONSTR_ACTION_SETNULL:
fk_trigger->deferrable = false;
fk_trigger->initdeferred = false;
fk_trigger->funcname = SystemFuncName("RI_FKey_setnull_del");
break;
case FKCONSTR_ACTION_SETDEFAULT:
fk_trigger->deferrable = false;
fk_trigger->initdeferred = false;
fk_trigger->funcname = SystemFuncName("RI_FKey_setdefault_del");
break;
default:
elog(ERROR, "unrecognized FK action type: %d",
(int) fkconstraint->fk_del_action);
break;
}
fk_trigger->args = NIL;
(void) CreateTrigger(fk_trigger, NULL, refRelOid, RelationGetRelid(rel),
constraintOid,
indexOid, InvalidOid, InvalidOid, NULL, true, false);
/* Make changes-so-far visible */
CommandCounterIncrement();
/*
* Build and execute a CREATE CONSTRAINT TRIGGER statement for the ON
* UPDATE action on the referenced table.
*/
fk_trigger = makeNode(CreateTrigStmt);
fk_trigger->trigname = "RI_ConstraintTrigger_a";
fk_trigger->relation = NULL;
fk_trigger->row = true;
fk_trigger->timing = TRIGGER_TYPE_AFTER;
fk_trigger->events = TRIGGER_TYPE_UPDATE;
fk_trigger->columns = NIL;
fk_trigger->transitionRels = NIL;
fk_trigger->whenClause = NULL;
fk_trigger->isconstraint = true;
fk_trigger->constrrel = NULL;
switch (fkconstraint->fk_upd_action)
{
case FKCONSTR_ACTION_NOACTION:
fk_trigger->deferrable = fkconstraint->deferrable;
fk_trigger->initdeferred = fkconstraint->initdeferred;
fk_trigger->funcname = SystemFuncName("RI_FKey_noaction_upd");
break;
case FKCONSTR_ACTION_RESTRICT:
fk_trigger->deferrable = false;
fk_trigger->initdeferred = false;
fk_trigger->funcname = SystemFuncName("RI_FKey_restrict_upd");
break;
case FKCONSTR_ACTION_CASCADE:
fk_trigger->deferrable = false;
fk_trigger->initdeferred = false;
fk_trigger->funcname = SystemFuncName("RI_FKey_cascade_upd");
break;
case FKCONSTR_ACTION_SETNULL:
fk_trigger->deferrable = false;
fk_trigger->initdeferred = false;
fk_trigger->funcname = SystemFuncName("RI_FKey_setnull_upd");
break;
case FKCONSTR_ACTION_SETDEFAULT:
fk_trigger->deferrable = false;
fk_trigger->initdeferred = false;
fk_trigger->funcname = SystemFuncName("RI_FKey_setdefault_upd");
break;
default:
elog(ERROR, "unrecognized FK action type: %d",
(int) fkconstraint->fk_upd_action);
break;
}
fk_trigger->args = NIL;
(void) CreateTrigger(fk_trigger, NULL, refRelOid, RelationGetRelid(rel),
constraintOid,
indexOid, InvalidOid, InvalidOid, NULL, true, false);
}
/*
* createForeignKeyCheckTriggers
* Create the referencing-side "check" triggers that implement a foreign
* key.
*/
static void
createForeignKeyCheckTriggers(Oid myRelOid, Oid refRelOid,
Constraint *fkconstraint, Oid constraintOid,
Oid indexOid)
{
CreateFKCheckTrigger(myRelOid, refRelOid, fkconstraint, constraintOid,
indexOid, true);
CreateFKCheckTrigger(myRelOid, refRelOid, fkconstraint, constraintOid,
indexOid, false);
}
/*
* ALTER TABLE DROP CONSTRAINT
*
* Like DROP COLUMN, we can't use the normal ALTER TABLE recursion mechanism.
*/
static void
ATExecDropConstraint(Relation rel, const char *constrName,
DropBehavior behavior,
bool recurse, bool recursing,
bool missing_ok, LOCKMODE lockmode)
{
List *children;
ListCell *child;
Relation conrel;
Form_pg_constraint con;
SysScanDesc scan;
ScanKeyData skey[3];
HeapTuple tuple;
bool found = false;
bool is_no_inherit_constraint = false;
char contype;
/* At top level, permission check was done in ATPrepCmd, else do it */
if (recursing)
ATSimplePermissions(rel, ATT_TABLE | ATT_FOREIGN_TABLE);
conrel = table_open(ConstraintRelationId, RowExclusiveLock);
/*
* Find and drop the target constraint
*/
ScanKeyInit(&skey[0],
Anum_pg_constraint_conrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(rel)));
ScanKeyInit(&skey[1],
Anum_pg_constraint_contypid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(InvalidOid));
ScanKeyInit(&skey[2],
Anum_pg_constraint_conname,
BTEqualStrategyNumber, F_NAMEEQ,
CStringGetDatum(constrName));
scan = systable_beginscan(conrel, ConstraintRelidTypidNameIndexId,
true, NULL, 3, skey);
/* There can be at most one matching row */
if (HeapTupleIsValid(tuple = systable_getnext(scan)))
{
ObjectAddress conobj;
con = (Form_pg_constraint) GETSTRUCT(tuple);
/* Don't drop inherited constraints */
if (con->coninhcount > 0 && !recursing)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("cannot drop inherited constraint \"%s\" of relation \"%s\"",
constrName, RelationGetRelationName(rel))));
is_no_inherit_constraint = con->connoinherit;
contype = con->contype;
/*
* If it's a foreign-key constraint, we'd better lock the referenced
* table and check that that's not in use, just as we've already done
* for the constrained table (else we might, eg, be dropping a trigger
* that has unfired events). But we can/must skip that in the
* self-referential case.
*/
if (contype == CONSTRAINT_FOREIGN &&
con->confrelid != RelationGetRelid(rel))
{
Relation frel;
/* Must match lock taken by RemoveTriggerById: */
frel = table_open(con->confrelid, AccessExclusiveLock);
CheckTableNotInUse(frel, "ALTER TABLE");
table_close(frel, NoLock);
}
/*
* Perform the actual constraint deletion
*/
conobj.classId = ConstraintRelationId;
conobj.objectId = con->oid;
conobj.objectSubId = 0;
performDeletion(&conobj, behavior, 0);
found = true;
}
systable_endscan(scan);
if (!found)
{
if (!missing_ok)
{
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("constraint \"%s\" of relation \"%s\" does not exist",
constrName, RelationGetRelationName(rel))));
}
else
{
ereport(NOTICE,
(errmsg("constraint \"%s\" of relation \"%s\" does not exist, skipping",
constrName, RelationGetRelationName(rel))));
table_close(conrel, RowExclusiveLock);
return;
}
}
/*
* For partitioned tables, non-CHECK inherited constraints are dropped via
* the dependency mechanism, so we're done here.
*/
if (contype != CONSTRAINT_CHECK &&
rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
{
table_close(conrel, RowExclusiveLock);
return;
}
/*
* Propagate to children as appropriate. Unlike most other ALTER
* routines, we have to do this one level of recursion at a time; we can't
* use find_all_inheritors to do it in one pass.
*/
if (!is_no_inherit_constraint)
children = find_inheritance_children(RelationGetRelid(rel), lockmode);
else
children = NIL;
/*
* For a partitioned table, if partitions exist and we are told not to
* recurse, it's a user error. It doesn't make sense to have a constraint
* be defined only on the parent, especially if it's a partitioned table.
*/
if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE &&
children != NIL && !recurse)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("cannot remove constraint from only the partitioned table when partitions exist"),
errhint("Do not specify the ONLY keyword.")));
foreach(child, children)
{
Oid childrelid = lfirst_oid(child);
Relation childrel;
HeapTuple copy_tuple;
/* find_inheritance_children already got lock */
childrel = table_open(childrelid, NoLock);
CheckTableNotInUse(childrel, "ALTER TABLE");
ScanKeyInit(&skey[0],
Anum_pg_constraint_conrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(childrelid));
ScanKeyInit(&skey[1],
Anum_pg_constraint_contypid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(InvalidOid));
ScanKeyInit(&skey[2],
Anum_pg_constraint_conname,
BTEqualStrategyNumber, F_NAMEEQ,
CStringGetDatum(constrName));
scan = systable_beginscan(conrel, ConstraintRelidTypidNameIndexId,
true, NULL, 3, skey);
/* There can be at most one matching row */
if (!HeapTupleIsValid(tuple = systable_getnext(scan)))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("constraint \"%s\" of relation \"%s\" does not exist",
constrName,
RelationGetRelationName(childrel))));
copy_tuple = heap_copytuple(tuple);
systable_endscan(scan);
con = (Form_pg_constraint) GETSTRUCT(copy_tuple);
/* Right now only CHECK constraints can be inherited */
if (con->contype != CONSTRAINT_CHECK)
elog(ERROR, "inherited constraint is not a CHECK constraint");
if (con->coninhcount <= 0) /* shouldn't happen */
elog(ERROR, "relation %u has non-inherited constraint \"%s\"",
childrelid, constrName);
if (recurse)
{
/*
* If the child constraint has other definition sources, just
* decrement its inheritance count; if not, recurse to delete it.
*/
if (con->coninhcount == 1 && !con->conislocal)
{
/* Time to delete this child constraint, too */
ATExecDropConstraint(childrel, constrName, behavior,
true, true,
false, lockmode);
}
else
{
/* Child constraint must survive my deletion */
con->coninhcount--;
CatalogTupleUpdate(conrel, &copy_tuple->t_self, copy_tuple);
/* Make update visible */
CommandCounterIncrement();
}
}
else
{
/*
* If we were told to drop ONLY in this table (no recursion), we
* need to mark the inheritors' constraints as locally defined
* rather than inherited.
*/
con->coninhcount--;
con->conislocal = true;
CatalogTupleUpdate(conrel, &copy_tuple->t_self, copy_tuple);
/* Make update visible */
CommandCounterIncrement();
}
heap_freetuple(copy_tuple);
table_close(childrel, NoLock);
}
table_close(conrel, RowExclusiveLock);
}
/*
* ALTER COLUMN TYPE
*/
static void
ATPrepAlterColumnType(List **wqueue,
AlteredTableInfo *tab, Relation rel,
bool recurse, bool recursing,
AlterTableCmd *cmd, LOCKMODE lockmode)
{
char *colName = cmd->name;
ColumnDef *def = (ColumnDef *) cmd->def;
TypeName *typeName = def->typeName;
Node *transform = def->cooked_default;
HeapTuple tuple;
Form_pg_attribute attTup;
AttrNumber attnum;
Oid targettype;
int32 targettypmod;
Oid targetcollid;
NewColumnValue *newval;
ParseState *pstate = make_parsestate(NULL);
AclResult aclresult;
bool is_expr;
if (rel->rd_rel->reloftype && !recursing)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot alter column type of typed table")));
/* lookup the attribute so we can check inheritance status */
tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName);
if (!HeapTupleIsValid(tuple))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" of relation \"%s\" does not exist",
colName, RelationGetRelationName(rel))));
attTup = (Form_pg_attribute) GETSTRUCT(tuple);
attnum = attTup->attnum;
/* Can't alter a system attribute */
if (attnum <= 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter system column \"%s\"",
colName)));
/*
* Don't alter inherited columns. At outer level, there had better not be
* any inherited definition; when recursing, we assume this was checked at
* the parent level (see below).
*/
if (attTup->attinhcount > 0 && !recursing)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("cannot alter inherited column \"%s\"",
colName)));
/* Don't alter columns used in the partition key */
if (has_partition_attrs(rel,
bms_make_singleton(attnum - FirstLowInvalidHeapAttributeNumber),
&is_expr))
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("cannot alter column \"%s\" because it is part of the partition key of relation \"%s\"",
colName, RelationGetRelationName(rel))));
/* Look up the target type */
typenameTypeIdAndMod(NULL, typeName, &targettype, &targettypmod);
aclresult = pg_type_aclcheck(targettype, GetUserId(), ACL_USAGE);
if (aclresult != ACLCHECK_OK)
aclcheck_error_type(aclresult, targettype);
/* And the collation */
targetcollid = GetColumnDefCollation(NULL, def, targettype);
/* make sure datatype is legal for a column */
CheckAttributeType(colName, targettype, targetcollid,
list_make1_oid(rel->rd_rel->reltype),
0);
if (tab->relkind == RELKIND_RELATION ||
tab->relkind == RELKIND_PARTITIONED_TABLE)
{
/*
* Set up an expression to transform the old data value to the new
* type. If a USING option was given, use the expression as
* transformed by transformAlterTableStmt, else just take the old
* value and try to coerce it. We do this first so that type
* incompatibility can be detected before we waste effort, and because
* we need the expression to be parsed against the original table row
* type.
*/
if (!transform)
{
transform = (Node *) makeVar(1, attnum,
attTup->atttypid, attTup->atttypmod,
attTup->attcollation,
0);
}
transform = coerce_to_target_type(pstate,
transform, exprType(transform),
targettype, targettypmod,
COERCION_ASSIGNMENT,
COERCE_IMPLICIT_CAST,
-1);
if (transform == NULL)
{
/* error text depends on whether USING was specified or not */
if (def->cooked_default != NULL)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("result of USING clause for column \"%s\""
" cannot be cast automatically to type %s",
colName, format_type_be(targettype)),
errhint("You might need to add an explicit cast.")));
else
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("column \"%s\" cannot be cast automatically to type %s",
colName, format_type_be(targettype)),
/* translator: USING is SQL, don't translate it */
errhint("You might need to specify \"USING %s::%s\".",
quote_identifier(colName),
format_type_with_typemod(targettype,
targettypmod))));
}
/* Fix collations after all else */
assign_expr_collations(pstate, transform);
/* Plan the expr now so we can accurately assess the need to rewrite. */
transform = (Node *) expression_planner((Expr *) transform);
/*
* Add a work queue item to make ATRewriteTable update the column
* contents.
*/
newval = (NewColumnValue *) palloc0(sizeof(NewColumnValue));
newval->attnum = attnum;
newval->expr = (Expr *) transform;
tab->newvals = lappend(tab->newvals, newval);
if (ATColumnChangeRequiresRewrite(transform, attnum))
tab->rewrite |= AT_REWRITE_COLUMN_REWRITE;
}
else if (transform)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a table",
RelationGetRelationName(rel))));
if (tab->relkind == RELKIND_COMPOSITE_TYPE ||
tab->relkind == RELKIND_FOREIGN_TABLE)
{
/*
* For composite types, do this check now. Tables will check it later
* when the table is being rewritten.
*/
find_composite_type_dependencies(rel->rd_rel->reltype, rel, NULL);
}
ReleaseSysCache(tuple);
/*
* Recurse manually by queueing a new command for each child, if
* necessary. We cannot apply ATSimpleRecursion here because we need to
* remap attribute numbers in the USING expression, if any.
*
* If we are told not to recurse, there had better not be any child
* tables; else the alter would put them out of step.
*/
if (recurse)
{
Oid relid = RelationGetRelid(rel);
List *child_oids,
*child_numparents;
ListCell *lo,
*li;
child_oids = find_all_inheritors(relid, lockmode,
&child_numparents);
/*
* find_all_inheritors does the recursive search of the inheritance
* hierarchy, so all we have to do is process all of the relids in the
* list that it returns.
*/
forboth(lo, child_oids, li, child_numparents)
{
Oid childrelid = lfirst_oid(lo);
int numparents = lfirst_int(li);
Relation childrel;
HeapTuple childtuple;
Form_pg_attribute childattTup;
if (childrelid == relid)
continue;
/* find_all_inheritors already got lock */
childrel = relation_open(childrelid, NoLock);
CheckTableNotInUse(childrel, "ALTER TABLE");
/*
* Verify that the child doesn't have any inherited definitions of
* this column that came from outside this inheritance hierarchy.
* (renameatt makes a similar test, though in a different way
* because of its different recursion mechanism.)
*/
childtuple = SearchSysCacheAttName(RelationGetRelid(childrel),
colName);
if (!HeapTupleIsValid(childtuple))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" of relation \"%s\" does not exist",
colName, RelationGetRelationName(childrel))));
childattTup = (Form_pg_attribute) GETSTRUCT(childtuple);
if (childattTup->attinhcount > numparents)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("cannot alter inherited column \"%s\" of relation \"%s\"",
colName, RelationGetRelationName(childrel))));
ReleaseSysCache(childtuple);
/*
* Remap the attribute numbers. If no USING expression was
* specified, there is no need for this step.
*/
if (def->cooked_default)
{
AttrNumber *attmap;
bool found_whole_row;
/* create a copy to scribble on */
cmd = copyObject(cmd);
attmap = convert_tuples_by_name_map(RelationGetDescr(childrel),
RelationGetDescr(rel));
((ColumnDef *) cmd->def)->cooked_default =
map_variable_attnos(def->cooked_default,
1, 0,
attmap, RelationGetDescr(rel)->natts,
InvalidOid, &found_whole_row);
if (found_whole_row)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot convert whole-row table reference"),
errdetail("USING expression contains a whole-row table reference.")));
pfree(attmap);
}
ATPrepCmd(wqueue, childrel, cmd, false, true, lockmode);
relation_close(childrel, NoLock);
}
}
else if (!recursing &&
find_inheritance_children(RelationGetRelid(rel), NoLock) != NIL)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("type of inherited column \"%s\" must be changed in child tables too",
colName)));
if (tab->relkind == RELKIND_COMPOSITE_TYPE)
ATTypedTableRecursion(wqueue, rel, cmd, lockmode);
}
/*
* When the data type of a column is changed, a rewrite might not be required
* if the new type is sufficiently identical to the old one, and the USING
* clause isn't trying to insert some other value. It's safe to skip the
* rewrite in these cases:
*
* - the old type is binary coercible to the new type
* - the new type is an unconstrained domain over the old type
* - {NEW,OLD} or {OLD,NEW} is {timestamptz,timestamp} and the timezone is UTC
*
* In the case of a constrained domain, we could get by with scanning the
* table and checking the constraint rather than actually rewriting it, but we
* don't currently try to do that.
*/
static bool
ATColumnChangeRequiresRewrite(Node *expr, AttrNumber varattno)
{
Assert(expr != NULL);
for (;;)
{
/* only one varno, so no need to check that */
if (IsA(expr, Var) &&((Var *) expr)->varattno == varattno)
return false;
else if (IsA(expr, RelabelType))
expr = (Node *) ((RelabelType *) expr)->arg;
else if (IsA(expr, CoerceToDomain))
{
CoerceToDomain *d = (CoerceToDomain *) expr;
if (DomainHasConstraints(d->resulttype))
return true;
expr = (Node *) d->arg;
}
else if (IsA(expr, FuncExpr))
{
FuncExpr *f = (FuncExpr *) expr;
switch (f->funcid)
{
case F_TIMESTAMPTZ_TIMESTAMP:
case F_TIMESTAMP_TIMESTAMPTZ:
if (TimestampTimestampTzRequiresRewrite())
return true;
else
expr = linitial(f->args);
break;
default:
return true;
}
}
else
return true;
}
}
/*
* ALTER COLUMN .. SET DATA TYPE
*
* Return the address of the modified column.
*/
static ObjectAddress
ATExecAlterColumnType(AlteredTableInfo *tab, Relation rel,
AlterTableCmd *cmd, LOCKMODE lockmode)
{
char *colName = cmd->name;
ColumnDef *def = (ColumnDef *) cmd->def;
TypeName *typeName = def->typeName;
HeapTuple heapTup;
Form_pg_attribute attTup,
attOldTup;
AttrNumber attnum;
HeapTuple typeTuple;
Form_pg_type tform;
Oid targettype;
int32 targettypmod;
Oid targetcollid;
Node *defaultexpr;
Relation attrelation;
Relation depRel;
ScanKeyData key[3];
SysScanDesc scan;
HeapTuple depTup;
ObjectAddress address;
/*
* Clear all the missing values if we're rewriting the table, since this
* renders them pointless.
*/
if (tab->rewrite)
{
Relation newrel;
newrel = table_open(RelationGetRelid(rel), NoLock);
RelationClearMissing(newrel);
relation_close(newrel, NoLock);
/* make sure we don't conflict with later attribute modifications */
CommandCounterIncrement();
}
attrelation = table_open(AttributeRelationId, RowExclusiveLock);
/* Look up the target column */
heapTup = SearchSysCacheCopyAttName(RelationGetRelid(rel), colName);
if (!HeapTupleIsValid(heapTup)) /* shouldn't happen */
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" of relation \"%s\" does not exist",
colName, RelationGetRelationName(rel))));
attTup = (Form_pg_attribute) GETSTRUCT(heapTup);
attnum = attTup->attnum;
attOldTup = TupleDescAttr(tab->oldDesc, attnum - 1);
/* Check for multiple ALTER TYPE on same column --- can't cope */
if (attTup->atttypid != attOldTup->atttypid ||
attTup->atttypmod != attOldTup->atttypmod)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter type of column \"%s\" twice",
colName)));
/* Look up the target type (should not fail, since prep found it) */
typeTuple = typenameType(NULL, typeName, &targettypmod);
tform = (Form_pg_type) GETSTRUCT(typeTuple);
targettype = tform->oid;
/* And the collation */
targetcollid = GetColumnDefCollation(NULL, def, targettype);
/*
* If there is a default expression for the column, get it and ensure we
* can coerce it to the new datatype. (We must do this before changing
* the column type, because build_column_default itself will try to
* coerce, and will not issue the error message we want if it fails.)
*
* We remove any implicit coercion steps at the top level of the old
* default expression; this has been agreed to satisfy the principle of
* least surprise. (The conversion to the new column type should act like
* it started from what the user sees as the stored expression, and the
* implicit coercions aren't going to be shown.)
*/
if (attTup->atthasdef)
{
defaultexpr = build_column_default(rel, attnum);
Assert(defaultexpr);
defaultexpr = strip_implicit_coercions(defaultexpr);
defaultexpr = coerce_to_target_type(NULL, /* no UNKNOWN params */
defaultexpr, exprType(defaultexpr),
targettype, targettypmod,
COERCION_ASSIGNMENT,
COERCE_IMPLICIT_CAST,
-1);
if (defaultexpr == NULL)
{
if (attTup->attgenerated)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("generation expression for column \"%s\" cannot be cast automatically to type %s",
colName, format_type_be(targettype))));
else
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("default for column \"%s\" cannot be cast automatically to type %s",
colName, format_type_be(targettype))));
}
}
else
defaultexpr = NULL;
/*
* Find everything that depends on the column (constraints, indexes, etc),
* and record enough information to let us recreate the objects.
*
* The actual recreation does not happen here, but only after we have
* performed all the individual ALTER TYPE operations. We have to save
* the info before executing ALTER TYPE, though, else the deparser will
* get confused.
*/
depRel = table_open(DependRelationId, RowExclusiveLock);
ScanKeyInit(&key[0],
Anum_pg_depend_refclassid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationRelationId));
ScanKeyInit(&key[1],
Anum_pg_depend_refobjid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(rel)));
ScanKeyInit(&key[2],
Anum_pg_depend_refobjsubid,
BTEqualStrategyNumber, F_INT4EQ,
Int32GetDatum((int32) attnum));
scan = systable_beginscan(depRel, DependReferenceIndexId, true,
NULL, 3, key);
while (HeapTupleIsValid(depTup = systable_getnext(scan)))
{
Form_pg_depend foundDep = (Form_pg_depend) GETSTRUCT(depTup);
ObjectAddress foundObject;
/* We don't expect any PIN dependencies on columns */
if (foundDep->deptype == DEPENDENCY_PIN)
elog(ERROR, "cannot alter type of a pinned column");
foundObject.classId = foundDep->classid;
foundObject.objectId = foundDep->objid;
foundObject.objectSubId = foundDep->objsubid;
switch (getObjectClass(&foundObject))
{
case OCLASS_CLASS:
{
char relKind = get_rel_relkind(foundObject.objectId);
if (relKind == RELKIND_INDEX ||
relKind == RELKIND_PARTITIONED_INDEX)
{
Assert(foundObject.objectSubId == 0);
RememberIndexForRebuilding(foundObject.objectId, tab);
}
else if (relKind == RELKIND_SEQUENCE)
{
/*
* This must be a SERIAL column's sequence. We need
* not do anything to it.
*/
Assert(foundObject.objectSubId == 0);
}
else if (relKind == RELKIND_RELATION &&
foundObject.objectSubId != 0 &&
get_attgenerated(foundObject.objectId, foundObject.objectSubId))
{
/*
* Changing the type of a column that is used by a
* generated column is not allowed by SQL standard. It
* might be doable with some thinking and effort.
*/
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot alter type of a column used by a generated column"),
errdetail("Column \"%s\" is used by generated column \"%s\".",
colName, get_attname(foundObject.objectId, foundObject.objectSubId, false))));
}
else
{
/* Not expecting any other direct dependencies... */
elog(ERROR, "unexpected object depending on column: %s",
getObjectDescription(&foundObject));
}
break;
}
case OCLASS_CONSTRAINT:
Assert(foundObject.objectSubId == 0);
RememberConstraintForRebuilding(foundObject.objectId, tab);
break;
case OCLASS_REWRITE:
/* XXX someday see if we can cope with revising views */
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter type of a column used by a view or rule"),
errdetail("%s depends on column \"%s\"",
getObjectDescription(&foundObject),
colName)));
break;
case OCLASS_TRIGGER:
/*
* A trigger can depend on a column because the column is
* specified as an update target, or because the column is
* used in the trigger's WHEN condition. The first case would
* not require any extra work, but the second case would
* require updating the WHEN expression, which will take a
* significant amount of new code. Since we can't easily tell
* which case applies, we punt for both. FIXME someday.
*/
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter type of a column used in a trigger definition"),
errdetail("%s depends on column \"%s\"",
getObjectDescription(&foundObject),
colName)));
break;
case OCLASS_POLICY:
/*
* A policy can depend on a column because the column is
* specified in the policy's USING or WITH CHECK qual
* expressions. It might be possible to rewrite and recheck
* the policy expression, but punt for now. It's certainly
* easy enough to remove and recreate the policy; still, FIXME
* someday.
*/
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter type of a column used in a policy definition"),
errdetail("%s depends on column \"%s\"",
getObjectDescription(&foundObject),
colName)));
break;
case OCLASS_DEFAULT:
/*
* Ignore the column's default expression, since we will fix
* it below.
*/
Assert(defaultexpr);
break;
case OCLASS_STATISTIC_EXT:
/*
* Give the extended-stats machinery a chance to fix anything
* that this column type change would break.
*/
UpdateStatisticsForTypeChange(foundObject.objectId,
RelationGetRelid(rel), attnum,
attTup->atttypid, targettype);
break;
case OCLASS_PROC:
case OCLASS_TYPE:
case OCLASS_CAST:
case OCLASS_COLLATION:
case OCLASS_CONVERSION:
case OCLASS_LANGUAGE:
case OCLASS_LARGEOBJECT:
case OCLASS_OPERATOR:
case OCLASS_OPCLASS:
case OCLASS_OPFAMILY:
case OCLASS_AM:
case OCLASS_AMOP:
case OCLASS_AMPROC:
case OCLASS_SCHEMA:
case OCLASS_TSPARSER:
case OCLASS_TSDICT:
case OCLASS_TSTEMPLATE:
case OCLASS_TSCONFIG:
case OCLASS_ROLE:
case OCLASS_DATABASE:
case OCLASS_TBLSPACE:
case OCLASS_FDW:
case OCLASS_FOREIGN_SERVER:
case OCLASS_USER_MAPPING:
case OCLASS_DEFACL:
case OCLASS_EXTENSION:
case OCLASS_EVENT_TRIGGER:
case OCLASS_PUBLICATION:
case OCLASS_PUBLICATION_REL:
case OCLASS_SUBSCRIPTION:
case OCLASS_TRANSFORM:
/*
* We don't expect any of these sorts of objects to depend on
* a column.
*/
elog(ERROR, "unexpected object depending on column: %s",
getObjectDescription(&foundObject));
break;
/*
* There's intentionally no default: case here; we want the
* compiler to warn if a new OCLASS hasn't been handled above.
*/
}
}
systable_endscan(scan);
/*
* Now scan for dependencies of this column on other things. The only
* thing we should find is the dependency on the column datatype, which we
* want to remove, possibly a collation dependency, and dependencies on
* other columns if it is a generated column.
*/
ScanKeyInit(&key[0],
Anum_pg_depend_classid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationRelationId));
ScanKeyInit(&key[1],
Anum_pg_depend_objid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(rel)));
ScanKeyInit(&key[2],
Anum_pg_depend_objsubid,
BTEqualStrategyNumber, F_INT4EQ,
Int32GetDatum((int32) attnum));
scan = systable_beginscan(depRel, DependDependerIndexId, true,
NULL, 3, key);
while (HeapTupleIsValid(depTup = systable_getnext(scan)))
{
Form_pg_depend foundDep = (Form_pg_depend) GETSTRUCT(depTup);
ObjectAddress foundObject;
foundObject.classId = foundDep->refclassid;
foundObject.objectId = foundDep->refobjid;
foundObject.objectSubId = foundDep->refobjsubid;
if (foundDep->deptype != DEPENDENCY_NORMAL &&
foundDep->deptype != DEPENDENCY_AUTO)
elog(ERROR, "found unexpected dependency type '%c'",
foundDep->deptype);
if (!(foundDep->refclassid == TypeRelationId &&
foundDep->refobjid == attTup->atttypid) &&
!(foundDep->refclassid == CollationRelationId &&
foundDep->refobjid == attTup->attcollation) &&
!(foundDep->refclassid == RelationRelationId &&
foundDep->refobjid == RelationGetRelid(rel) &&
foundDep->refobjsubid != 0)
)
elog(ERROR, "found unexpected dependency for column: %s",
getObjectDescription(&foundObject));
CatalogTupleDelete(depRel, &depTup->t_self);
}
systable_endscan(scan);
table_close(depRel, RowExclusiveLock);
/*
* Here we go --- change the recorded column type and collation. (Note
* heapTup is a copy of the syscache entry, so okay to scribble on.) First
* fix up the missing value if any.
*/
if (attTup->atthasmissing)
{
Datum missingval;
bool missingNull;
/* if rewrite is true the missing value should already be cleared */
Assert(tab->rewrite == 0);
/* Get the missing value datum */
missingval = heap_getattr(heapTup,
Anum_pg_attribute_attmissingval,
attrelation->rd_att,
&missingNull);
/* if it's a null array there is nothing to do */
if (!missingNull)
{
/*
* Get the datum out of the array and repack it in a new array
* built with the new type data. We assume that since the table
* doesn't need rewriting, the actual Datum doesn't need to be
* changed, only the array metadata.
*/
int one = 1;
bool isNull;
Datum valuesAtt[Natts_pg_attribute];
bool nullsAtt[Natts_pg_attribute];
bool replacesAtt[Natts_pg_attribute];
HeapTuple newTup;
MemSet(valuesAtt, 0, sizeof(valuesAtt));
MemSet(nullsAtt, false, sizeof(nullsAtt));
MemSet(replacesAtt, false, sizeof(replacesAtt));
missingval = array_get_element(missingval,
1,
&one,
0,
attTup->attlen,
attTup->attbyval,
attTup->attalign,
&isNull);
missingval = PointerGetDatum(
construct_array(&missingval,
1,
targettype,
tform->typlen,
tform->typbyval,
tform->typalign));
valuesAtt[Anum_pg_attribute_attmissingval - 1] = missingval;
replacesAtt[Anum_pg_attribute_attmissingval - 1] = true;
nullsAtt[Anum_pg_attribute_attmissingval - 1] = false;
newTup = heap_modify_tuple(heapTup, RelationGetDescr(attrelation),
valuesAtt, nullsAtt, replacesAtt);
heap_freetuple(heapTup);
heapTup = newTup;
attTup = (Form_pg_attribute) GETSTRUCT(heapTup);
}
}
attTup->atttypid = targettype;
attTup->atttypmod = targettypmod;
attTup->attcollation = targetcollid;
attTup->attndims = list_length(typeName->arrayBounds);
attTup->attlen = tform->typlen;
attTup->attbyval = tform->typbyval;
attTup->attalign = tform->typalign;
attTup->attstorage = tform->typstorage;
ReleaseSysCache(typeTuple);
CatalogTupleUpdate(attrelation, &heapTup->t_self, heapTup);
table_close(attrelation, RowExclusiveLock);
/* Install dependencies on new datatype and collation */
add_column_datatype_dependency(RelationGetRelid(rel), attnum, targettype);
add_column_collation_dependency(RelationGetRelid(rel), attnum, targetcollid);
/*
* Drop any pg_statistic entry for the column, since it's now wrong type
*/
RemoveStatistics(RelationGetRelid(rel), attnum);
InvokeObjectPostAlterHook(RelationRelationId,
RelationGetRelid(rel), attnum);
/*
* Update the default, if present, by brute force --- remove and re-add
* the default. Probably unsafe to take shortcuts, since the new version
* may well have additional dependencies. (It's okay to do this now,
* rather than after other ALTER TYPE commands, since the default won't
* depend on other column types.)
*/
if (defaultexpr)
{
/* Must make new row visible since it will be updated again */
CommandCounterIncrement();
/*
* We use RESTRICT here for safety, but at present we do not expect
* anything to depend on the default.
*/
RemoveAttrDefault(RelationGetRelid(rel), attnum, DROP_RESTRICT, true,
true);
StoreAttrDefault(rel, attnum, defaultexpr, true, false);
}
ObjectAddressSubSet(address, RelationRelationId,
RelationGetRelid(rel), attnum);
/* Cleanup */
heap_freetuple(heapTup);
return address;
}
/*
* Subroutine for ATExecAlterColumnType: remember that a constraint needs
* to be rebuilt (which we might already know).
*/
static void
RememberConstraintForRebuilding(Oid conoid, AlteredTableInfo *tab)
{
/*
* This de-duplication check is critical for two independent reasons: we
* mustn't try to recreate the same constraint twice, and if a constraint
* depends on more than one column whose type is to be altered, we must
* capture its definition string before applying any of the column type
* changes. ruleutils.c will get confused if we ask again later.
*/
if (!list_member_oid(tab->changedConstraintOids, conoid))
{
/* OK, capture the constraint's existing definition string */
char *defstring = pg_get_constraintdef_command(conoid);
tab->changedConstraintOids = lappend_oid(tab->changedConstraintOids,
conoid);
tab->changedConstraintDefs = lappend(tab->changedConstraintDefs,
defstring);
}
}
/*
* Subroutine for ATExecAlterColumnType: remember that an index needs
* to be rebuilt (which we might already know).
*/
static void
RememberIndexForRebuilding(Oid indoid, AlteredTableInfo *tab)
{
/*
* This de-duplication check is critical for two independent reasons: we
* mustn't try to recreate the same index twice, and if an index depends
* on more than one column whose type is to be altered, we must capture
* its definition string before applying any of the column type changes.
* ruleutils.c will get confused if we ask again later.
*/
if (!list_member_oid(tab->changedIndexOids, indoid))
{
/*
* Before adding it as an index-to-rebuild, we'd better see if it
* belongs to a constraint, and if so rebuild the constraint instead.
* Typically this check fails, because constraint indexes normally
* have only dependencies on their constraint. But it's possible for
* such an index to also have direct dependencies on table columns,
* for example with a partial exclusion constraint.
*/
Oid conoid = get_index_constraint(indoid);
if (OidIsValid(conoid))
{
RememberConstraintForRebuilding(conoid, tab);
}
else
{
/* OK, capture the index's existing definition string */
char *defstring = pg_get_indexdef_string(indoid);
tab->changedIndexOids = lappend_oid(tab->changedIndexOids,
indoid);
tab->changedIndexDefs = lappend(tab->changedIndexDefs,
defstring);
}
}
}
/*
* Cleanup after we've finished all the ALTER TYPE operations for a
* particular relation. We have to drop and recreate all the indexes
* and constraints that depend on the altered columns. We do the
* actual dropping here, but re-creation is managed by adding work
* queue entries to do those steps later.
*/
static void
ATPostAlterTypeCleanup(List **wqueue, AlteredTableInfo *tab, LOCKMODE lockmode)
{
ObjectAddress obj;
ObjectAddresses *objects;
ListCell *def_item;
ListCell *oid_item;
/*
* Collect all the constraints and indexes to drop so we can process them
* in a single call. That way we don't have to worry about dependencies
* among them.
*/
objects = new_object_addresses();
/*
* Re-parse the index and constraint definitions, and attach them to the
* appropriate work queue entries. We do this before dropping because in
* the case of a FOREIGN KEY constraint, we might not yet have exclusive
* lock on the table the constraint is attached to, and we need to get
* that before reparsing/dropping.
*
* We can't rely on the output of deparsing to tell us which relation to
* operate on, because concurrent activity might have made the name
* resolve differently. Instead, we've got to use the OID of the
* constraint or index we're processing to figure out which relation to
* operate on.
*/
forboth(oid_item, tab->changedConstraintOids,
def_item, tab->changedConstraintDefs)
{
Oid oldId = lfirst_oid(oid_item);
HeapTuple tup;
Form_pg_constraint con;
Oid relid;
Oid confrelid;
char contype;
bool conislocal;
tup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(oldId));
if (!HeapTupleIsValid(tup)) /* should not happen */
elog(ERROR, "cache lookup failed for constraint %u", oldId);
con = (Form_pg_constraint) GETSTRUCT(tup);
if (OidIsValid(con->conrelid))
relid = con->conrelid;
else
{
/* must be a domain constraint */
relid = get_typ_typrelid(getBaseType(con->contypid));
if (!OidIsValid(relid))
elog(ERROR, "could not identify relation associated with constraint %u", oldId);
}
confrelid = con->confrelid;
contype = con->contype;
conislocal = con->conislocal;
ReleaseSysCache(tup);
ObjectAddressSet(obj, ConstraintRelationId, oldId);
add_exact_object_address(&obj, objects);
/*
* If the constraint is inherited (only), we don't want to inject a
* new definition here; it'll get recreated when ATAddCheckConstraint
* recurses from adding the parent table's constraint. But we had to
* carry the info this far so that we can drop the constraint below.
*/
if (!conislocal)
continue;
/*
* When rebuilding an FK constraint that references the table we're
* modifying, we might not yet have any lock on the FK's table, so get
* one now. We'll need AccessExclusiveLock for the DROP CONSTRAINT
* step, so there's no value in asking for anything weaker.
*/
if (relid != tab->relid && contype == CONSTRAINT_FOREIGN)
LockRelationOid(relid, AccessExclusiveLock);
ATPostAlterTypeParse(oldId, relid, confrelid,
(char *) lfirst(def_item),
wqueue, lockmode, tab->rewrite);
}
forboth(oid_item, tab->changedIndexOids,
def_item, tab->changedIndexDefs)
{
Oid oldId = lfirst_oid(oid_item);
Oid relid;
relid = IndexGetRelation(oldId, false);
ATPostAlterTypeParse(oldId, relid, InvalidOid,
(char *) lfirst(def_item),
wqueue, lockmode, tab->rewrite);
ObjectAddressSet(obj, RelationRelationId, oldId);
add_exact_object_address(&obj, objects);
}
/*
* It should be okay to use DROP_RESTRICT here, since nothing else should
* be depending on these objects.
*/
performMultipleDeletions(objects, DROP_RESTRICT, PERFORM_DELETION_INTERNAL);
free_object_addresses(objects);
/*
* The objects will get recreated during subsequent passes over the work
* queue.
*/
}
/*
* Parse the previously-saved definition string for a constraint or index
* against the newly-established column data type(s), and queue up the
* resulting command parsetrees for execution.
*
* This might fail if, for example, you have a WHERE clause that uses an
* operator that's not available for the new column type.
*/
static void
ATPostAlterTypeParse(Oid oldId, Oid oldRelId, Oid refRelId, char *cmd,
List **wqueue, LOCKMODE lockmode, bool rewrite)
{
List *raw_parsetree_list;
List *querytree_list;
ListCell *list_item;
Relation rel;
/*
* We expect that we will get only ALTER TABLE and CREATE INDEX
* statements. Hence, there is no need to pass them through
* parse_analyze() or the rewriter, but instead we need to pass them
* through parse_utilcmd.c to make them ready for execution.
*/
raw_parsetree_list = raw_parser(cmd);
querytree_list = NIL;
foreach(list_item, raw_parsetree_list)
{
RawStmt *rs = lfirst_node(RawStmt, list_item);
Node *stmt = rs->stmt;
if (IsA(stmt, IndexStmt))
querytree_list = lappend(querytree_list,
transformIndexStmt(oldRelId,
(IndexStmt *) stmt,
cmd));
else if (IsA(stmt, AlterTableStmt))
querytree_list = list_concat(querytree_list,
transformAlterTableStmt(oldRelId,
(AlterTableStmt *) stmt,
cmd));
else
querytree_list = lappend(querytree_list, stmt);
}
/* Caller should already have acquired whatever lock we need. */
rel = relation_open(oldRelId, NoLock);
/*
* Attach each generated command to the proper place in the work queue.
* Note this could result in creation of entirely new work-queue entries.
*
* Also note that we have to tweak the command subtypes, because it turns
* out that re-creation of indexes and constraints has to act a bit
* differently from initial creation.
*/
foreach(list_item, querytree_list)
{
Node *stm = (Node *) lfirst(list_item);
AlteredTableInfo *tab;
tab = ATGetQueueEntry(wqueue, rel);
if (IsA(stm, IndexStmt))
{
IndexStmt *stmt = (IndexStmt *) stm;
AlterTableCmd *newcmd;
if (!rewrite)
TryReuseIndex(oldId, stmt);
stmt->reset_default_tblspc = true;
/* keep the index's comment */
stmt->idxcomment = GetComment(oldId, RelationRelationId, 0);
newcmd = makeNode(AlterTableCmd);
newcmd->subtype = AT_ReAddIndex;
newcmd->def = (Node *) stmt;
tab->subcmds[AT_PASS_OLD_INDEX] =
lappend(tab->subcmds[AT_PASS_OLD_INDEX], newcmd);
}
else if (IsA(stm, AlterTableStmt))
{
AlterTableStmt *stmt = (AlterTableStmt *) stm;
ListCell *lcmd;
foreach(lcmd, stmt->cmds)
{
AlterTableCmd *cmd = castNode(AlterTableCmd, lfirst(lcmd));
if (cmd->subtype == AT_AddIndex)
{
IndexStmt *indstmt;
Oid indoid;
indstmt = castNode(IndexStmt, cmd->def);
indoid = get_constraint_index(oldId);
if (!rewrite)
TryReuseIndex(indoid, indstmt);
/* keep any comment on the index */
indstmt->idxcomment = GetComment(indoid,
RelationRelationId, 0);
indstmt->reset_default_tblspc = true;
cmd->subtype = AT_ReAddIndex;
tab->subcmds[AT_PASS_OLD_INDEX] =
lappend(tab->subcmds[AT_PASS_OLD_INDEX], cmd);
/* recreate any comment on the constraint */
RebuildConstraintComment(tab,
AT_PASS_OLD_INDEX,
oldId,
rel,
NIL,
indstmt->idxname);
}
else if (cmd->subtype == AT_AddConstraint)
{
Constraint *con = castNode(Constraint, cmd->def);
con->old_pktable_oid = refRelId;
/* rewriting neither side of a FK */
if (con->contype == CONSTR_FOREIGN &&
!rewrite && tab->rewrite == 0)
TryReuseForeignKey(oldId, con);
con->reset_default_tblspc = true;
cmd->subtype = AT_ReAddConstraint;
tab->subcmds[AT_PASS_OLD_CONSTR] =
lappend(tab->subcmds[AT_PASS_OLD_CONSTR], cmd);
/* recreate any comment on the constraint */
RebuildConstraintComment(tab,
AT_PASS_OLD_CONSTR,
oldId,
rel,
NIL,
con->conname);
}
else if (cmd->subtype == AT_SetNotNull)
{
/*
* The parser will create AT_SetNotNull subcommands for
* columns of PRIMARY KEY indexes/constraints, but we need
* not do anything with them here, because the columns'
* NOT NULL marks will already have been propagated into
* the new table definition.
*/
}
else
elog(ERROR, "unexpected statement subtype: %d",
(int) cmd->subtype);
}
}
else if (IsA(stm, AlterDomainStmt))
{
AlterDomainStmt *stmt = (AlterDomainStmt *) stm;
if (stmt->subtype == 'C') /* ADD CONSTRAINT */
{
Constraint *con = castNode(Constraint, stmt->def);
AlterTableCmd *cmd = makeNode(AlterTableCmd);
cmd->subtype = AT_ReAddDomainConstraint;
cmd->def = (Node *) stmt;
tab->subcmds[AT_PASS_OLD_CONSTR] =
lappend(tab->subcmds[AT_PASS_OLD_CONSTR], cmd);
/* recreate any comment on the constraint */
RebuildConstraintComment(tab,
AT_PASS_OLD_CONSTR,
oldId,
NULL,
stmt->typeName,
con->conname);
}
else
elog(ERROR, "unexpected statement subtype: %d",
(int) stmt->subtype);
}
else
elog(ERROR, "unexpected statement type: %d",
(int) nodeTag(stm));
}
relation_close(rel, NoLock);
}
/*
* Subroutine for ATPostAlterTypeParse() to recreate any existing comment
* for a table or domain constraint that is being rebuilt.
*
* objid is the OID of the constraint.
* Pass "rel" for a table constraint, or "domname" (domain's qualified name
* as a string list) for a domain constraint.
* (We could dig that info, as well as the conname, out of the pg_constraint
* entry; but callers already have them so might as well pass them.)
*/
static void
RebuildConstraintComment(AlteredTableInfo *tab, int pass, Oid objid,
Relation rel, List *domname,
const char *conname)
{
CommentStmt *cmd;
char *comment_str;
AlterTableCmd *newcmd;
/* Look for comment for object wanted, and leave if none */
comment_str = GetComment(objid, ConstraintRelationId, 0);
if (comment_str == NULL)
return;
/* Build CommentStmt node, copying all input data for safety */
cmd = makeNode(CommentStmt);
if (rel)
{
cmd->objtype = OBJECT_TABCONSTRAINT;
cmd->object = (Node *)
list_make3(makeString(get_namespace_name(RelationGetNamespace(rel))),
makeString(pstrdup(RelationGetRelationName(rel))),
makeString(pstrdup(conname)));
}
else
{
cmd->objtype = OBJECT_DOMCONSTRAINT;
cmd->object = (Node *)
list_make2(makeTypeNameFromNameList(copyObject(domname)),
makeString(pstrdup(conname)));
}
cmd->comment = comment_str;
/* Append it to list of commands */
newcmd = makeNode(AlterTableCmd);
newcmd->subtype = AT_ReAddComment;
newcmd->def = (Node *) cmd;
tab->subcmds[pass] = lappend(tab->subcmds[pass], newcmd);
}
/*
* Subroutine for ATPostAlterTypeParse(). Calls out to CheckIndexCompatible()
* for the real analysis, then mutates the IndexStmt based on that verdict.
*/
static void
TryReuseIndex(Oid oldId, IndexStmt *stmt)
{
if (CheckIndexCompatible(oldId,
stmt->accessMethod,
stmt->indexParams,
stmt->excludeOpNames))
{
Relation irel = index_open(oldId, NoLock);
/* If it's a partitioned index, there is no storage to share. */
if (irel->rd_rel->relkind != RELKIND_PARTITIONED_INDEX)
stmt->oldNode = irel->rd_node.relNode;
index_close(irel, NoLock);
}
}
/*
* Subroutine for ATPostAlterTypeParse().
*
* Stash the old P-F equality operator into the Constraint node, for possible
* use by ATAddForeignKeyConstraint() in determining whether revalidation of
* this constraint can be skipped.
*/
static void
TryReuseForeignKey(Oid oldId, Constraint *con)
{
HeapTuple tup;
Datum adatum;
bool isNull;
ArrayType *arr;
Oid *rawarr;
int numkeys;
int i;
Assert(con->contype == CONSTR_FOREIGN);
Assert(con->old_conpfeqop == NIL); /* already prepared this node */
tup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(oldId));
if (!HeapTupleIsValid(tup)) /* should not happen */
elog(ERROR, "cache lookup failed for constraint %u", oldId);
adatum = SysCacheGetAttr(CONSTROID, tup,
Anum_pg_constraint_conpfeqop, &isNull);
if (isNull)
elog(ERROR, "null conpfeqop for constraint %u", oldId);
arr = DatumGetArrayTypeP(adatum); /* ensure not toasted */
numkeys = ARR_DIMS(arr)[0];
/* test follows the one in ri_FetchConstraintInfo() */
if (ARR_NDIM(arr) != 1 ||
ARR_HASNULL(arr) ||
ARR_ELEMTYPE(arr) != OIDOID)
elog(ERROR, "conpfeqop is not a 1-D Oid array");
rawarr = (Oid *) ARR_DATA_PTR(arr);
/* stash a List of the operator Oids in our Constraint node */
for (i = 0; i < numkeys; i++)
con->old_conpfeqop = lappend_oid(con->old_conpfeqop, rawarr[i]);
ReleaseSysCache(tup);
}
/*
* ALTER COLUMN .. OPTIONS ( ... )
*
* Returns the address of the modified column
*/
static ObjectAddress
ATExecAlterColumnGenericOptions(Relation rel,
const char *colName,
List *options,
LOCKMODE lockmode)
{
Relation ftrel;
Relation attrel;
ForeignServer *server;
ForeignDataWrapper *fdw;
HeapTuple tuple;
HeapTuple newtuple;
bool isnull;
Datum repl_val[Natts_pg_attribute];
bool repl_null[Natts_pg_attribute];
bool repl_repl[Natts_pg_attribute];
Datum datum;
Form_pg_foreign_table fttableform;
Form_pg_attribute atttableform;
AttrNumber attnum;
ObjectAddress address;
if (options == NIL)
return InvalidObjectAddress;
/* First, determine FDW validator associated to the foreign table. */
ftrel = table_open(ForeignTableRelationId, AccessShareLock);
tuple = SearchSysCache1(FOREIGNTABLEREL, rel->rd_id);
if (!HeapTupleIsValid(tuple))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("foreign table \"%s\" does not exist",
RelationGetRelationName(rel))));
fttableform = (Form_pg_foreign_table) GETSTRUCT(tuple);
server = GetForeignServer(fttableform->ftserver);
fdw = GetForeignDataWrapper(server->fdwid);
table_close(ftrel, AccessShareLock);
ReleaseSysCache(tuple);
attrel = table_open(AttributeRelationId, RowExclusiveLock);
tuple = SearchSysCacheAttName(RelationGetRelid(rel), colName);
if (!HeapTupleIsValid(tuple))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" of relation \"%s\" does not exist",
colName, RelationGetRelationName(rel))));
/* Prevent them from altering a system attribute */
atttableform = (Form_pg_attribute) GETSTRUCT(tuple);
attnum = atttableform->attnum;
if (attnum <= 0)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot alter system column \"%s\"", colName)));
/* Initialize buffers for new tuple values */
memset(repl_val, 0, sizeof(repl_val));
memset(repl_null, false, sizeof(repl_null));
memset(repl_repl, false, sizeof(repl_repl));
/* Extract the current options */
datum = SysCacheGetAttr(ATTNAME,
tuple,
Anum_pg_attribute_attfdwoptions,
&isnull);
if (isnull)
datum = PointerGetDatum(NULL);
/* Transform the options */
datum = transformGenericOptions(AttributeRelationId,
datum,
options,
fdw->fdwvalidator);
if (PointerIsValid(DatumGetPointer(datum)))
repl_val[Anum_pg_attribute_attfdwoptions - 1] = datum;
else
repl_null[Anum_pg_attribute_attfdwoptions - 1] = true;
repl_repl[Anum_pg_attribute_attfdwoptions - 1] = true;
/* Everything looks good - update the tuple */
newtuple = heap_modify_tuple(tuple, RelationGetDescr(attrel),
repl_val, repl_null, repl_repl);
CatalogTupleUpdate(attrel, &newtuple->t_self, newtuple);
InvokeObjectPostAlterHook(RelationRelationId,
RelationGetRelid(rel),
atttableform->attnum);
ObjectAddressSubSet(address, RelationRelationId,
RelationGetRelid(rel), attnum);
ReleaseSysCache(tuple);
table_close(attrel, RowExclusiveLock);
heap_freetuple(newtuple);
return address;
}
/*
* ALTER TABLE OWNER
*
* recursing is true if we are recursing from a table to its indexes,
* sequences, or toast table. We don't allow the ownership of those things to
* be changed separately from the parent table. Also, we can skip permission
* checks (this is necessary not just an optimization, else we'd fail to
* handle toast tables properly).
*
* recursing is also true if ALTER TYPE OWNER is calling us to fix up a
* free-standing composite type.
*/
void
ATExecChangeOwner(Oid relationOid, Oid newOwnerId, bool recursing, LOCKMODE lockmode)
{
Relation target_rel;
Relation class_rel;
HeapTuple tuple;
Form_pg_class tuple_class;
/*
* Get exclusive lock till end of transaction on the target table. Use
* relation_open so that we can work on indexes and sequences.
*/
target_rel = relation_open(relationOid, lockmode);
/* Get its pg_class tuple, too */
class_rel = table_open(RelationRelationId, RowExclusiveLock);
tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relationOid));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for relation %u", relationOid);
tuple_class = (Form_pg_class) GETSTRUCT(tuple);
/* Can we change the ownership of this tuple? */
switch (tuple_class->relkind)
{
case RELKIND_RELATION:
case RELKIND_VIEW:
case RELKIND_MATVIEW:
case RELKIND_FOREIGN_TABLE:
case RELKIND_PARTITIONED_TABLE:
/* ok to change owner */
break;
case RELKIND_INDEX:
if (!recursing)
{
/*
* Because ALTER INDEX OWNER used to be allowed, and in fact
* is generated by old versions of pg_dump, we give a warning
* and do nothing rather than erroring out. Also, to avoid
* unnecessary chatter while restoring those old dumps, say
* nothing at all if the command would be a no-op anyway.
*/
if (tuple_class->relowner != newOwnerId)
ereport(WARNING,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot change owner of index \"%s\"",
NameStr(tuple_class->relname)),
errhint("Change the ownership of the index's table, instead.")));
/* quick hack to exit via the no-op path */
newOwnerId = tuple_class->relowner;
}
break;
case RELKIND_PARTITIONED_INDEX:
if (recursing)
break;
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot change owner of index \"%s\"",
NameStr(tuple_class->relname)),
errhint("Change the ownership of the index's table, instead.")));
break;
case RELKIND_SEQUENCE:
if (!recursing &&
tuple_class->relowner != newOwnerId)
{
/* if it's an owned sequence, disallow changing it by itself */
Oid tableId;
int32 colId;
if (sequenceIsOwned(relationOid, DEPENDENCY_AUTO, &tableId, &colId) ||
sequenceIsOwned(relationOid, DEPENDENCY_INTERNAL, &tableId, &colId))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot change owner of sequence \"%s\"",
NameStr(tuple_class->relname)),
errdetail("Sequence \"%s\" is linked to table \"%s\".",
NameStr(tuple_class->relname),
get_rel_name(tableId))));
}
break;
case RELKIND_COMPOSITE_TYPE:
if (recursing)
break;
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is a composite type",
NameStr(tuple_class->relname)),
errhint("Use ALTER TYPE instead.")));
break;
case RELKIND_TOASTVALUE:
if (recursing)
break;
/* FALL THRU */
default:
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a table, view, sequence, or foreign table",
NameStr(tuple_class->relname))));
}
/*
* If the new owner is the same as the existing owner, consider the
* command to have succeeded. This is for dump restoration purposes.
*/
if (tuple_class->relowner != newOwnerId)
{
Datum repl_val[Natts_pg_class];
bool repl_null[Natts_pg_class];
bool repl_repl[Natts_pg_class];
Acl *newAcl;
Datum aclDatum;
bool isNull;
HeapTuple newtuple;
/* skip permission checks when recursing to index or toast table */
if (!recursing)
{
/* Superusers can always do it */
if (!superuser())
{
Oid namespaceOid = tuple_class->relnamespace;
AclResult aclresult;
/* Otherwise, must be owner of the existing object */
if (!pg_class_ownercheck(relationOid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(relationOid)),
RelationGetRelationName(target_rel));
/* Must be able to become new owner */
check_is_member_of_role(GetUserId(), newOwnerId);
/* New owner must have CREATE privilege on namespace */
aclresult = pg_namespace_aclcheck(namespaceOid, newOwnerId,
ACL_CREATE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, OBJECT_SCHEMA,
get_namespace_name(namespaceOid));
}
}
memset(repl_null, false, sizeof(repl_null));
memset(repl_repl, false, sizeof(repl_repl));
repl_repl[Anum_pg_class_relowner - 1] = true;
repl_val[Anum_pg_class_relowner - 1] = ObjectIdGetDatum(newOwnerId);
/*
* Determine the modified ACL for the new owner. This is only
* necessary when the ACL is non-null.
*/
aclDatum = SysCacheGetAttr(RELOID, tuple,
Anum_pg_class_relacl,
&isNull);
if (!isNull)
{
newAcl = aclnewowner(DatumGetAclP(aclDatum),
tuple_class->relowner, newOwnerId);
repl_repl[Anum_pg_class_relacl - 1] = true;
repl_val[Anum_pg_class_relacl - 1] = PointerGetDatum(newAcl);
}
newtuple = heap_modify_tuple(tuple, RelationGetDescr(class_rel), repl_val, repl_null, repl_repl);
CatalogTupleUpdate(class_rel, &newtuple->t_self, newtuple);
heap_freetuple(newtuple);
/*
* We must similarly update any per-column ACLs to reflect the new
* owner; for neatness reasons that's split out as a subroutine.
*/
change_owner_fix_column_acls(relationOid,
tuple_class->relowner,
newOwnerId);
/*
* Update owner dependency reference, if any. A composite type has
* none, because it's tracked for the pg_type entry instead of here;
* indexes and TOAST tables don't have their own entries either.
*/
if (tuple_class->relkind != RELKIND_COMPOSITE_TYPE &&
tuple_class->relkind != RELKIND_INDEX &&
tuple_class->relkind != RELKIND_PARTITIONED_INDEX &&
tuple_class->relkind != RELKIND_TOASTVALUE)
changeDependencyOnOwner(RelationRelationId, relationOid,
newOwnerId);
/*
* Also change the ownership of the table's row type, if it has one
*/
if (tuple_class->relkind != RELKIND_INDEX &&
tuple_class->relkind != RELKIND_PARTITIONED_INDEX)
AlterTypeOwnerInternal(tuple_class->reltype, newOwnerId);
/*
* If we are operating on a table or materialized view, also change
* the ownership of any indexes and sequences that belong to the
* relation, as well as its toast table (if it has one).
*/
if (tuple_class->relkind == RELKIND_RELATION ||
tuple_class->relkind == RELKIND_PARTITIONED_TABLE ||
tuple_class->relkind == RELKIND_MATVIEW ||
tuple_class->relkind == RELKIND_TOASTVALUE)
{
List *index_oid_list;
ListCell *i;
/* Find all the indexes belonging to this relation */
index_oid_list = RelationGetIndexList(target_rel);
/* For each index, recursively change its ownership */
foreach(i, index_oid_list)
ATExecChangeOwner(lfirst_oid(i), newOwnerId, true, lockmode);
list_free(index_oid_list);
}
/* If it has a toast table, recurse to change its ownership */
if (tuple_class->reltoastrelid != InvalidOid)
ATExecChangeOwner(tuple_class->reltoastrelid, newOwnerId,
true, lockmode);
/* If it has dependent sequences, recurse to change them too */
change_owner_recurse_to_sequences(relationOid, newOwnerId, lockmode);
}
InvokeObjectPostAlterHook(RelationRelationId, relationOid, 0);
ReleaseSysCache(tuple);
table_close(class_rel, RowExclusiveLock);
relation_close(target_rel, NoLock);
}
/*
* change_owner_fix_column_acls
*
* Helper function for ATExecChangeOwner. Scan the columns of the table
* and fix any non-null column ACLs to reflect the new owner.
*/
static void
change_owner_fix_column_acls(Oid relationOid, Oid oldOwnerId, Oid newOwnerId)
{
Relation attRelation;
SysScanDesc scan;
ScanKeyData key[1];
HeapTuple attributeTuple;
attRelation = table_open(AttributeRelationId, RowExclusiveLock);
ScanKeyInit(&key[0],
Anum_pg_attribute_attrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(relationOid));
scan = systable_beginscan(attRelation, AttributeRelidNumIndexId,
true, NULL, 1, key);
while (HeapTupleIsValid(attributeTuple = systable_getnext(scan)))
{
Form_pg_attribute att = (Form_pg_attribute) GETSTRUCT(attributeTuple);
Datum repl_val[Natts_pg_attribute];
bool repl_null[Natts_pg_attribute];
bool repl_repl[Natts_pg_attribute];
Acl *newAcl;
Datum aclDatum;
bool isNull;
HeapTuple newtuple;
/* Ignore dropped columns */
if (att->attisdropped)
continue;
aclDatum = heap_getattr(attributeTuple,
Anum_pg_attribute_attacl,
RelationGetDescr(attRelation),
&isNull);
/* Null ACLs do not require changes */
if (isNull)
continue;
memset(repl_null, false, sizeof(repl_null));
memset(repl_repl, false, sizeof(repl_repl));
newAcl = aclnewowner(DatumGetAclP(aclDatum),
oldOwnerId, newOwnerId);
repl_repl[Anum_pg_attribute_attacl - 1] = true;
repl_val[Anum_pg_attribute_attacl - 1] = PointerGetDatum(newAcl);
newtuple = heap_modify_tuple(attributeTuple,
RelationGetDescr(attRelation),
repl_val, repl_null, repl_repl);
CatalogTupleUpdate(attRelation, &newtuple->t_self, newtuple);
heap_freetuple(newtuple);
}
systable_endscan(scan);
table_close(attRelation, RowExclusiveLock);
}
/*
* change_owner_recurse_to_sequences
*
* Helper function for ATExecChangeOwner. Examines pg_depend searching
* for sequences that are dependent on serial columns, and changes their
* ownership.
*/
static void
change_owner_recurse_to_sequences(Oid relationOid, Oid newOwnerId, LOCKMODE lockmode)
{
Relation depRel;
SysScanDesc scan;
ScanKeyData key[2];
HeapTuple tup;
/*
* SERIAL sequences are those having an auto dependency on one of the
* table's columns (we don't care *which* column, exactly).
*/
depRel = table_open(DependRelationId, AccessShareLock);
ScanKeyInit(&key[0],
Anum_pg_depend_refclassid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationRelationId));
ScanKeyInit(&key[1],
Anum_pg_depend_refobjid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(relationOid));
/* we leave refobjsubid unspecified */
scan = systable_beginscan(depRel, DependReferenceIndexId, true,
NULL, 2, key);
while (HeapTupleIsValid(tup = systable_getnext(scan)))
{
Form_pg_depend depForm = (Form_pg_depend) GETSTRUCT(tup);
Relation seqRel;
/* skip dependencies other than auto dependencies on columns */
if (depForm->refobjsubid == 0 ||
depForm->classid != RelationRelationId ||
depForm->objsubid != 0 ||
!(depForm->deptype == DEPENDENCY_AUTO || depForm->deptype == DEPENDENCY_INTERNAL))
continue;
/* Use relation_open just in case it's an index */
seqRel = relation_open(depForm->objid, lockmode);
/* skip non-sequence relations */
if (RelationGetForm(seqRel)->relkind != RELKIND_SEQUENCE)
{
/* No need to keep the lock */
relation_close(seqRel, lockmode);
continue;
}
/* We don't need to close the sequence while we alter it. */
ATExecChangeOwner(depForm->objid, newOwnerId, true, lockmode);
/* Now we can close it. Keep the lock till end of transaction. */
relation_close(seqRel, NoLock);
}
systable_endscan(scan);
relation_close(depRel, AccessShareLock);
}
/*
* ALTER TABLE CLUSTER ON
*
* The only thing we have to do is to change the indisclustered bits.
*
* Return the address of the new clustering index.
*/
static ObjectAddress
ATExecClusterOn(Relation rel, const char *indexName, LOCKMODE lockmode)
{
Oid indexOid;
ObjectAddress address;
indexOid = get_relname_relid(indexName, rel->rd_rel->relnamespace);
if (!OidIsValid(indexOid))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("index \"%s\" for table \"%s\" does not exist",
indexName, RelationGetRelationName(rel))));
/* Check index is valid to cluster on */
check_index_is_clusterable(rel, indexOid, false, lockmode);
/* And do the work */
mark_index_clustered(rel, indexOid, false);
ObjectAddressSet(address,
RelationRelationId, indexOid);
return address;
}
/*
* ALTER TABLE SET WITHOUT CLUSTER
*
* We have to find any indexes on the table that have indisclustered bit
* set and turn it off.
*/
static void
ATExecDropCluster(Relation rel, LOCKMODE lockmode)
{
mark_index_clustered(rel, InvalidOid, false);
}
/*
* ALTER TABLE SET TABLESPACE
*/
static void
ATPrepSetTableSpace(AlteredTableInfo *tab, Relation rel, const char *tablespacename, LOCKMODE lockmode)
{
Oid tablespaceId;
/* Check that the tablespace exists */
tablespaceId = get_tablespace_oid(tablespacename, false);
/* Check permissions except when moving to database's default */
if (OidIsValid(tablespaceId) && tablespaceId != MyDatabaseTableSpace)
{
AclResult aclresult;
aclresult = pg_tablespace_aclcheck(tablespaceId, GetUserId(), ACL_CREATE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, OBJECT_TABLESPACE, tablespacename);
}
/* Save info for Phase 3 to do the real work */
if (OidIsValid(tab->newTableSpace))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot have multiple SET TABLESPACE subcommands")));
tab->newTableSpace = tablespaceId;
}
/*
* Set, reset, or replace reloptions.
*/
static void
ATExecSetRelOptions(Relation rel, List *defList, AlterTableType operation,
LOCKMODE lockmode)
{
Oid relid;
Relation pgclass;
HeapTuple tuple;
HeapTuple newtuple;
Datum datum;
bool isnull;
Datum newOptions;
Datum repl_val[Natts_pg_class];
bool repl_null[Natts_pg_class];
bool repl_repl[Natts_pg_class];
static char *validnsps[] = HEAP_RELOPT_NAMESPACES;
if (defList == NIL && operation != AT_ReplaceRelOptions)
return; /* nothing to do */
pgclass = table_open(RelationRelationId, RowExclusiveLock);
/* Fetch heap tuple */
relid = RelationGetRelid(rel);
tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for relation %u", relid);
if (operation == AT_ReplaceRelOptions)
{
/*
* If we're supposed to replace the reloptions list, we just pretend
* there were none before.
*/
datum = (Datum) 0;
isnull = true;
}
else
{
/* Get the old reloptions */
datum = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_reloptions,
&isnull);
}
/* Generate new proposed reloptions (text array) */
newOptions = transformRelOptions(isnull ? (Datum) 0 : datum,
defList, NULL, validnsps, false,
operation == AT_ResetRelOptions);
/* Validate */
switch (rel->rd_rel->relkind)
{
case RELKIND_RELATION:
case RELKIND_TOASTVALUE:
case RELKIND_MATVIEW:
case RELKIND_PARTITIONED_TABLE:
(void) heap_reloptions(rel->rd_rel->relkind, newOptions, true);
break;
case RELKIND_VIEW:
(void) view_reloptions(newOptions, true);
break;
case RELKIND_INDEX:
case RELKIND_PARTITIONED_INDEX:
(void) index_reloptions(rel->rd_indam->amoptions, newOptions, true);
break;
default:
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a table, view, materialized view, index, or TOAST table",
RelationGetRelationName(rel))));
break;
}
/* Special-case validation of view options */
if (rel->rd_rel->relkind == RELKIND_VIEW)
{
Query *view_query = get_view_query(rel);
List *view_options = untransformRelOptions(newOptions);
ListCell *cell;
bool check_option = false;
foreach(cell, view_options)
{
DefElem *defel = (DefElem *) lfirst(cell);
if (strcmp(defel->defname, "check_option") == 0)
check_option = true;
}
/*
* If the check option is specified, look to see if the view is
* actually auto-updatable or not.
*/
if (check_option)
{
const char *view_updatable_error =
view_query_is_auto_updatable(view_query, true);
if (view_updatable_error)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("WITH CHECK OPTION is supported only on automatically updatable views"),
errhint("%s", _(view_updatable_error))));
}
}
/*
* All we need do here is update the pg_class row; the new options will be
* propagated into relcaches during post-commit cache inval.
*/
memset(repl_val, 0, sizeof(repl_val));
memset(repl_null, false, sizeof(repl_null));
memset(repl_repl, false, sizeof(repl_repl));
if (newOptions != (Datum) 0)
repl_val[Anum_pg_class_reloptions - 1] = newOptions;
else
repl_null[Anum_pg_class_reloptions - 1] = true;
repl_repl[Anum_pg_class_reloptions - 1] = true;
newtuple = heap_modify_tuple(tuple, RelationGetDescr(pgclass),
repl_val, repl_null, repl_repl);
CatalogTupleUpdate(pgclass, &newtuple->t_self, newtuple);
InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0);
heap_freetuple(newtuple);
ReleaseSysCache(tuple);
/* repeat the whole exercise for the toast table, if there's one */
if (OidIsValid(rel->rd_rel->reltoastrelid))
{
Relation toastrel;
Oid toastid = rel->rd_rel->reltoastrelid;
toastrel = table_open(toastid, lockmode);
/* Fetch heap tuple */
tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(toastid));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for relation %u", toastid);
if (operation == AT_ReplaceRelOptions)
{
/*
* If we're supposed to replace the reloptions list, we just
* pretend there were none before.
*/
datum = (Datum) 0;
isnull = true;
}
else
{
/* Get the old reloptions */
datum = SysCacheGetAttr(RELOID, tuple, Anum_pg_class_reloptions,
&isnull);
}
newOptions = transformRelOptions(isnull ? (Datum) 0 : datum,
defList, "toast", validnsps, false,
operation == AT_ResetRelOptions);
(void) heap_reloptions(RELKIND_TOASTVALUE, newOptions, true);
memset(repl_val, 0, sizeof(repl_val));
memset(repl_null, false, sizeof(repl_null));
memset(repl_repl, false, sizeof(repl_repl));
if (newOptions != (Datum) 0)
repl_val[Anum_pg_class_reloptions - 1] = newOptions;
else
repl_null[Anum_pg_class_reloptions - 1] = true;
repl_repl[Anum_pg_class_reloptions - 1] = true;
newtuple = heap_modify_tuple(tuple, RelationGetDescr(pgclass),
repl_val, repl_null, repl_repl);
CatalogTupleUpdate(pgclass, &newtuple->t_self, newtuple);
InvokeObjectPostAlterHookArg(RelationRelationId,
RelationGetRelid(toastrel), 0,
InvalidOid, true);
heap_freetuple(newtuple);
ReleaseSysCache(tuple);
table_close(toastrel, NoLock);
}
table_close(pgclass, RowExclusiveLock);
}
/*
* Execute ALTER TABLE SET TABLESPACE for cases where there is no tuple
* rewriting to be done, so we just want to copy the data as fast as possible.
*/
static void
ATExecSetTableSpace(Oid tableOid, Oid newTableSpace, LOCKMODE lockmode)
{
Relation rel;
Oid oldTableSpace;
Oid reltoastrelid;
Oid newrelfilenode;
RelFileNode newrnode;
Relation pg_class;
HeapTuple tuple;
Form_pg_class rd_rel;
List *reltoastidxids = NIL;
ListCell *lc;
/*
* Need lock here in case we are recursing to toast table or index
*/
rel = relation_open(tableOid, lockmode);
/*
* No work if no change in tablespace.
*/
oldTableSpace = rel->rd_rel->reltablespace;
if (newTableSpace == oldTableSpace ||
(newTableSpace == MyDatabaseTableSpace && oldTableSpace == 0))
{
InvokeObjectPostAlterHook(RelationRelationId,
RelationGetRelid(rel), 0);
relation_close(rel, NoLock);
return;
}
/*
* We cannot support moving mapped relations into different tablespaces.
* (In particular this eliminates all shared catalogs.)
*/
if (RelationIsMapped(rel))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot move system relation \"%s\"",
RelationGetRelationName(rel))));
/* Can't move a non-shared relation into pg_global */
if (newTableSpace == GLOBALTABLESPACE_OID)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("only shared relations can be placed in pg_global tablespace")));
/*
* Don't allow moving temp tables of other backends ... their local buffer
* manager is not going to cope.
*/
if (RELATION_IS_OTHER_TEMP(rel))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot move temporary tables of other sessions")));
reltoastrelid = rel->rd_rel->reltoastrelid;
/* Fetch the list of indexes on toast relation if necessary */
if (OidIsValid(reltoastrelid))
{
Relation toastRel = relation_open(reltoastrelid, lockmode);
reltoastidxids = RelationGetIndexList(toastRel);
relation_close(toastRel, lockmode);
}
/* Get a modifiable copy of the relation's pg_class row */
pg_class = table_open(RelationRelationId, RowExclusiveLock);
tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(tableOid));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for relation %u", tableOid);
rd_rel = (Form_pg_class) GETSTRUCT(tuple);
/*
* Relfilenodes are not unique in databases across tablespaces, so we need
* to allocate a new one in the new tablespace.
*/
newrelfilenode = GetNewRelFileNode(newTableSpace, NULL,
rel->rd_rel->relpersistence);
/* Open old and new relation */
newrnode = rel->rd_node;
newrnode.relNode = newrelfilenode;
newrnode.spcNode = newTableSpace;
/* hand off to AM to actually create the new filenode and copy the data */
if (rel->rd_rel->relkind == RELKIND_INDEX)
{
index_copy_data(rel, newrnode);
}
else
{
Assert(rel->rd_rel->relkind == RELKIND_RELATION ||
rel->rd_rel->relkind == RELKIND_MATVIEW ||
rel->rd_rel->relkind == RELKIND_TOASTVALUE);
table_relation_copy_data(rel, &newrnode);
}
/*
* Update the pg_class row.
*
* NB: This wouldn't work if ATExecSetTableSpace() were allowed to be
* executed on pg_class or its indexes (the above copy wouldn't contain
* the updated pg_class entry), but that's forbidden above.
*/
rd_rel->reltablespace = (newTableSpace == MyDatabaseTableSpace) ? InvalidOid : newTableSpace;
rd_rel->relfilenode = newrelfilenode;
CatalogTupleUpdate(pg_class, &tuple->t_self, tuple);
InvokeObjectPostAlterHook(RelationRelationId, RelationGetRelid(rel), 0);
heap_freetuple(tuple);
table_close(pg_class, RowExclusiveLock);
relation_close(rel, NoLock);
/* Make sure the reltablespace change is visible */
CommandCounterIncrement();
/* Move associated toast relation and/or indexes, too */
if (OidIsValid(reltoastrelid))
ATExecSetTableSpace(reltoastrelid, newTableSpace, lockmode);
foreach(lc, reltoastidxids)
ATExecSetTableSpace(lfirst_oid(lc), newTableSpace, lockmode);
/* Clean up */
list_free(reltoastidxids);
}
/*
* Special handling of ALTER TABLE SET TABLESPACE for relations with no
* storage that have an interest in preserving tablespace.
*
* Since these have no storage the tablespace can be updated with a simple
* metadata only operation to update the tablespace.
*/
static void
ATExecSetTableSpaceNoStorage(Relation rel, Oid newTableSpace)
{
HeapTuple tuple;
Oid oldTableSpace;
Relation pg_class;
Form_pg_class rd_rel;
Oid reloid = RelationGetRelid(rel);
/*
* Shouldn't be called on relations having storage; these are processed in
* phase 3.
*/
Assert(!RELKIND_HAS_STORAGE(rel->rd_rel->relkind));
/* Can't allow a non-shared relation in pg_global */
if (newTableSpace == GLOBALTABLESPACE_OID)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("only shared relations can be placed in pg_global tablespace")));
/*
* No work if no change in tablespace.
*/
oldTableSpace = rel->rd_rel->reltablespace;
if (newTableSpace == oldTableSpace ||
(newTableSpace == MyDatabaseTableSpace && oldTableSpace == 0))
{
InvokeObjectPostAlterHook(RelationRelationId, reloid, 0);
return;
}
/* Get a modifiable copy of the relation's pg_class row */
pg_class = table_open(RelationRelationId, RowExclusiveLock);
tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(reloid));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for relation %u", reloid);
rd_rel = (Form_pg_class) GETSTRUCT(tuple);
/* update the pg_class row */
rd_rel->reltablespace = (newTableSpace == MyDatabaseTableSpace) ? InvalidOid : newTableSpace;
CatalogTupleUpdate(pg_class, &tuple->t_self, tuple);
InvokeObjectPostAlterHook(RelationRelationId, reloid, 0);
heap_freetuple(tuple);
table_close(pg_class, RowExclusiveLock);
/* Make sure the reltablespace change is visible */
CommandCounterIncrement();
}
/*
* Alter Table ALL ... SET TABLESPACE
*
* Allows a user to move all objects of some type in a given tablespace in the
* current database to another tablespace. Objects can be chosen based on the
* owner of the object also, to allow users to move only their objects.
* The user must have CREATE rights on the new tablespace, as usual. The main
* permissions handling is done by the lower-level table move function.
*
* All to-be-moved objects are locked first. If NOWAIT is specified and the
* lock can't be acquired then we ereport(ERROR).
*/
Oid
AlterTableMoveAll(AlterTableMoveAllStmt *stmt)
{
List *relations = NIL;
ListCell *l;
ScanKeyData key[1];
Relation rel;
TableScanDesc scan;
HeapTuple tuple;
Oid orig_tablespaceoid;
Oid new_tablespaceoid;
List *role_oids = roleSpecsToIds(stmt->roles);
/* Ensure we were not asked to move something we can't */
if (stmt->objtype != OBJECT_TABLE && stmt->objtype != OBJECT_INDEX &&
stmt->objtype != OBJECT_MATVIEW)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("only tables, indexes, and materialized views exist in tablespaces")));
/* Get the orig and new tablespace OIDs */
orig_tablespaceoid = get_tablespace_oid(stmt->orig_tablespacename, false);
new_tablespaceoid = get_tablespace_oid(stmt->new_tablespacename, false);
/* Can't move shared relations in to or out of pg_global */
/* This is also checked by ATExecSetTableSpace, but nice to stop earlier */
if (orig_tablespaceoid == GLOBALTABLESPACE_OID ||
new_tablespaceoid == GLOBALTABLESPACE_OID)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("cannot move relations in to or out of pg_global tablespace")));
/*
* Must have CREATE rights on the new tablespace, unless it is the
* database default tablespace (which all users implicitly have CREATE
* rights on).
*/
if (OidIsValid(new_tablespaceoid) && new_tablespaceoid != MyDatabaseTableSpace)
{
AclResult aclresult;
aclresult = pg_tablespace_aclcheck(new_tablespaceoid, GetUserId(),
ACL_CREATE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, OBJECT_TABLESPACE,
get_tablespace_name(new_tablespaceoid));
}
/*
* Now that the checks are done, check if we should set either to
* InvalidOid because it is our database's default tablespace.
*/
if (orig_tablespaceoid == MyDatabaseTableSpace)
orig_tablespaceoid = InvalidOid;
if (new_tablespaceoid == MyDatabaseTableSpace)
new_tablespaceoid = InvalidOid;
/* no-op */
if (orig_tablespaceoid == new_tablespaceoid)
return new_tablespaceoid;
/*
* Walk the list of objects in the tablespace and move them. This will
* only find objects in our database, of course.
*/
ScanKeyInit(&key[0],
Anum_pg_class_reltablespace,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(orig_tablespaceoid));
rel = table_open(RelationRelationId, AccessShareLock);
scan = table_beginscan_catalog(rel, 1, key);
while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
{
Form_pg_class relForm = (Form_pg_class) GETSTRUCT(tuple);
Oid relOid = relForm->oid;
/*
* Do not move objects in pg_catalog as part of this, if an admin
* really wishes to do so, they can issue the individual ALTER
* commands directly.
*
* Also, explicitly avoid any shared tables, temp tables, or TOAST
* (TOAST will be moved with the main table).
*/
if (IsCatalogNamespace(relForm->relnamespace) ||
relForm->relisshared ||
isAnyTempNamespace(relForm->relnamespace) ||
IsToastNamespace(relForm->relnamespace))
continue;
/* Only move the object type requested */
if ((stmt->objtype == OBJECT_TABLE &&
relForm->relkind != RELKIND_RELATION &&
relForm->relkind != RELKIND_PARTITIONED_TABLE) ||
(stmt->objtype == OBJECT_INDEX &&
relForm->relkind != RELKIND_INDEX &&
relForm->relkind != RELKIND_PARTITIONED_INDEX) ||
(stmt->objtype == OBJECT_MATVIEW &&
relForm->relkind != RELKIND_MATVIEW))
continue;
/* Check if we are only moving objects owned by certain roles */
if (role_oids != NIL && !list_member_oid(role_oids, relForm->relowner))
continue;
/*
* Handle permissions-checking here since we are locking the tables
* and also to avoid doing a bunch of work only to fail part-way. Note
* that permissions will also be checked by AlterTableInternal().
*
* Caller must be considered an owner on the table to move it.
*/
if (!pg_class_ownercheck(relOid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(relOid)),
NameStr(relForm->relname));
if (stmt->nowait &&
!ConditionalLockRelationOid(relOid, AccessExclusiveLock))
ereport(ERROR,
(errcode(ERRCODE_OBJECT_IN_USE),
errmsg("aborting because lock on relation \"%s.%s\" is not available",
get_namespace_name(relForm->relnamespace),
NameStr(relForm->relname))));
else
LockRelationOid(relOid, AccessExclusiveLock);
/* Add to our list of objects to move */
relations = lappend_oid(relations, relOid);
}
table_endscan(scan);
table_close(rel, AccessShareLock);
if (relations == NIL)
ereport(NOTICE,
(errcode(ERRCODE_NO_DATA_FOUND),
errmsg("no matching relations in tablespace \"%s\" found",
orig_tablespaceoid == InvalidOid ? "(database default)" :
get_tablespace_name(orig_tablespaceoid))));
/* Everything is locked, loop through and move all of the relations. */
foreach(l, relations)
{
List *cmds = NIL;
AlterTableCmd *cmd = makeNode(AlterTableCmd);
cmd->subtype = AT_SetTableSpace;
cmd->name = stmt->new_tablespacename;
cmds = lappend(cmds, cmd);
EventTriggerAlterTableStart((Node *) stmt);
/* OID is set by AlterTableInternal */
AlterTableInternal(lfirst_oid(l), cmds, false);
EventTriggerAlterTableEnd();
}
return new_tablespaceoid;
}
static void
index_copy_data(Relation rel, RelFileNode newrnode)
{
SMgrRelation dstrel;
dstrel = smgropen(newrnode, rel->rd_backend);
RelationOpenSmgr(rel);
/*
* Since we copy the file directly without looking at the shared buffers,
* we'd better first flush out any pages of the source relation that are
* in shared buffers. We assume no new changes will be made while we are
* holding exclusive lock on the rel.
*/
FlushRelationBuffers(rel);
/*
* Create and copy all forks of the relation, and schedule unlinking of
* old physical files.
*
* NOTE: any conflict in relfilenode value will be caught in
* RelationCreateStorage().
*/
RelationCreateStorage(newrnode, rel->rd_rel->relpersistence);
/* copy main fork */
RelationCopyStorage(rel->rd_smgr, dstrel, MAIN_FORKNUM,
rel->rd_rel->relpersistence);
/* copy those extra forks that exist */
for (ForkNumber forkNum = MAIN_FORKNUM + 1;
forkNum <= MAX_FORKNUM; forkNum++)
{
if (smgrexists(rel->rd_smgr, forkNum))
{
smgrcreate(dstrel, forkNum, false);
/*
* WAL log creation if the relation is persistent, or this is the
* init fork of an unlogged relation.
*/
if (rel->rd_rel->relpersistence == RELPERSISTENCE_PERMANENT ||
(rel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED &&
forkNum == INIT_FORKNUM))
log_smgrcreate(&newrnode, forkNum);
RelationCopyStorage(rel->rd_smgr, dstrel, forkNum,
rel->rd_rel->relpersistence);
}
}
/* drop old relation, and close new one */
RelationDropStorage(rel);
smgrclose(dstrel);
}
/*
* ALTER TABLE ENABLE/DISABLE TRIGGER
*
* We just pass this off to trigger.c.
*/
static void
ATExecEnableDisableTrigger(Relation rel, const char *trigname,
char fires_when, bool skip_system, LOCKMODE lockmode)
{
EnableDisableTrigger(rel, trigname, fires_when, skip_system, lockmode);
}
/*
* ALTER TABLE ENABLE/DISABLE RULE
*
* We just pass this off to rewriteDefine.c.
*/
static void
ATExecEnableDisableRule(Relation rel, const char *rulename,
char fires_when, LOCKMODE lockmode)
{
EnableDisableRule(rel, rulename, fires_when);
}
/*
* ALTER TABLE INHERIT
*
* Add a parent to the child's parents. This verifies that all the columns and
* check constraints of the parent appear in the child and that they have the
* same data types and expressions.
*/
static void
ATPrepAddInherit(Relation child_rel)
{
if (child_rel->rd_rel->reloftype)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot change inheritance of typed table")));
if (child_rel->rd_rel->relispartition)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot change inheritance of a partition")));
if (child_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot change inheritance of partitioned table")));
}
/*
* Return the address of the new parent relation.
*/
static ObjectAddress
ATExecAddInherit(Relation child_rel, RangeVar *parent, LOCKMODE lockmode)
{
Relation parent_rel;
List *children;
ObjectAddress address;
const char *trigger_name;
/*
* A self-exclusive lock is needed here. See the similar case in
* MergeAttributes() for a full explanation.
*/
parent_rel = table_openrv(parent, ShareUpdateExclusiveLock);
/*
* Must be owner of both parent and child -- child was checked by
* ATSimplePermissions call in ATPrepCmd
*/
ATSimplePermissions(parent_rel, ATT_TABLE | ATT_FOREIGN_TABLE);
/* Permanent rels cannot inherit from temporary ones */
if (parent_rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
child_rel->rd_rel->relpersistence != RELPERSISTENCE_TEMP)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot inherit from temporary relation \"%s\"",
RelationGetRelationName(parent_rel))));
/* If parent rel is temp, it must belong to this session */
if (parent_rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
!parent_rel->rd_islocaltemp)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot inherit from temporary relation of another session")));
/* Ditto for the child */
if (child_rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
!child_rel->rd_islocaltemp)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot inherit to temporary relation of another session")));
/* Prevent partitioned tables from becoming inheritance parents */
if (parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot inherit from partitioned table \"%s\"",
parent->relname)));
/* Likewise for partitions */
if (parent_rel->rd_rel->relispartition)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot inherit from a partition")));
/*
* Prevent circularity by seeing if proposed parent inherits from child.
* (In particular, this disallows making a rel inherit from itself.)
*
* This is not completely bulletproof because of race conditions: in
* multi-level inheritance trees, someone else could concurrently be
* making another inheritance link that closes the loop but does not join
* either of the rels we have locked. Preventing that seems to require
* exclusive locks on the entire inheritance tree, which is a cure worse
* than the disease. find_all_inheritors() will cope with circularity
* anyway, so don't sweat it too much.
*
* We use weakest lock we can on child's children, namely AccessShareLock.
*/
children = find_all_inheritors(RelationGetRelid(child_rel),
AccessShareLock, NULL);
if (list_member_oid(children, RelationGetRelid(parent_rel)))
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_TABLE),
errmsg("circular inheritance not allowed"),
errdetail("\"%s\" is already a child of \"%s\".",
parent->relname,
RelationGetRelationName(child_rel))));
/*
* If child_rel has row-level triggers with transition tables, we
* currently don't allow it to become an inheritance child. See also
* prohibitions in ATExecAttachPartition() and CreateTrigger().
*/
trigger_name = FindTriggerIncompatibleWithInheritance(child_rel->trigdesc);
if (trigger_name != NULL)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("trigger \"%s\" prevents table \"%s\" from becoming an inheritance child",
trigger_name, RelationGetRelationName(child_rel)),
errdetail("ROW triggers with transition tables are not supported in inheritance hierarchies.")));
/* OK to create inheritance */
CreateInheritance(child_rel, parent_rel);
ObjectAddressSet(address, RelationRelationId,
RelationGetRelid(parent_rel));
/* keep our lock on the parent relation until commit */
table_close(parent_rel, NoLock);
return address;
}
/*
* CreateInheritance
* Catalog manipulation portion of creating inheritance between a child
* table and a parent table.
*
* Common to ATExecAddInherit() and ATExecAttachPartition().
*/
static void
CreateInheritance(Relation child_rel, Relation parent_rel)
{
Relation catalogRelation;
SysScanDesc scan;
ScanKeyData key;
HeapTuple inheritsTuple;
int32 inhseqno;
/* Note: get RowExclusiveLock because we will write pg_inherits below. */
catalogRelation = table_open(InheritsRelationId, RowExclusiveLock);
/*
* Check for duplicates in the list of parents, and determine the highest
* inhseqno already present; we'll use the next one for the new parent.
* Also, if proposed child is a partition, it cannot already be
* inheriting.
*
* Note: we do not reject the case where the child already inherits from
* the parent indirectly; CREATE TABLE doesn't reject comparable cases.
*/
ScanKeyInit(&key,
Anum_pg_inherits_inhrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(child_rel)));
scan = systable_beginscan(catalogRelation, InheritsRelidSeqnoIndexId,
true, NULL, 1, &key);
/* inhseqno sequences start at 1 */
inhseqno = 0;
while (HeapTupleIsValid(inheritsTuple = systable_getnext(scan)))
{
Form_pg_inherits inh = (Form_pg_inherits) GETSTRUCT(inheritsTuple);
if (inh->inhparent == RelationGetRelid(parent_rel))
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_TABLE),
errmsg("relation \"%s\" would be inherited from more than once",
RelationGetRelationName(parent_rel))));
if (inh->inhseqno > inhseqno)
inhseqno = inh->inhseqno;
}
systable_endscan(scan);
/* Match up the columns and bump attinhcount as needed */
MergeAttributesIntoExisting(child_rel, parent_rel);
/* Match up the constraints and bump coninhcount as needed */
MergeConstraintsIntoExisting(child_rel, parent_rel);
/*
* OK, it looks valid. Make the catalog entries that show inheritance.
*/
StoreCatalogInheritance1(RelationGetRelid(child_rel),
RelationGetRelid(parent_rel),
inhseqno + 1,
catalogRelation,
parent_rel->rd_rel->relkind ==
RELKIND_PARTITIONED_TABLE);
/* Now we're done with pg_inherits */
table_close(catalogRelation, RowExclusiveLock);
}
/*
* Obtain the source-text form of the constraint expression for a check
* constraint, given its pg_constraint tuple
*/
static char *
decompile_conbin(HeapTuple contup, TupleDesc tupdesc)
{
Form_pg_constraint con;
bool isnull;
Datum attr;
Datum expr;
con = (Form_pg_constraint) GETSTRUCT(contup);
attr = heap_getattr(contup, Anum_pg_constraint_conbin, tupdesc, &isnull);
if (isnull)
elog(ERROR, "null conbin for constraint %u", con->oid);
expr = DirectFunctionCall2(pg_get_expr, attr,
ObjectIdGetDatum(con->conrelid));
return TextDatumGetCString(expr);
}
/*
* Determine whether two check constraints are functionally equivalent
*
* The test we apply is to see whether they reverse-compile to the same
* source string. This insulates us from issues like whether attributes
* have the same physical column numbers in parent and child relations.
*/
static bool
constraints_equivalent(HeapTuple a, HeapTuple b, TupleDesc tupleDesc)
{
Form_pg_constraint acon = (Form_pg_constraint) GETSTRUCT(a);
Form_pg_constraint bcon = (Form_pg_constraint) GETSTRUCT(b);
if (acon->condeferrable != bcon->condeferrable ||
acon->condeferred != bcon->condeferred ||
strcmp(decompile_conbin(a, tupleDesc),
decompile_conbin(b, tupleDesc)) != 0)
return false;
else
return true;
}
/*
* Check columns in child table match up with columns in parent, and increment
* their attinhcount.
*
* Called by CreateInheritance
*
* Currently all parent columns must be found in child. Missing columns are an
* error. One day we might consider creating new columns like CREATE TABLE
* does. However, that is widely unpopular --- in the common use case of
* partitioned tables it's a foot-gun.
*
* The data type must match exactly. If the parent column is NOT NULL then
* the child must be as well. Defaults are not compared, however.
*/
static void
MergeAttributesIntoExisting(Relation child_rel, Relation parent_rel)
{
Relation attrrel;
AttrNumber parent_attno;
int parent_natts;
TupleDesc tupleDesc;
HeapTuple tuple;
bool child_is_partition = false;
attrrel = table_open(AttributeRelationId, RowExclusiveLock);
tupleDesc = RelationGetDescr(parent_rel);
parent_natts = tupleDesc->natts;
/* If parent_rel is a partitioned table, child_rel must be a partition */
if (parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
child_is_partition = true;
for (parent_attno = 1; parent_attno <= parent_natts; parent_attno++)
{
Form_pg_attribute attribute = TupleDescAttr(tupleDesc,
parent_attno - 1);
char *attributeName = NameStr(attribute->attname);
/* Ignore dropped columns in the parent. */
if (attribute->attisdropped)
continue;
/* Find same column in child (matching on column name). */
tuple = SearchSysCacheCopyAttName(RelationGetRelid(child_rel),
attributeName);
if (HeapTupleIsValid(tuple))
{
/* Check they are same type, typmod, and collation */
Form_pg_attribute childatt = (Form_pg_attribute) GETSTRUCT(tuple);
if (attribute->atttypid != childatt->atttypid ||
attribute->atttypmod != childatt->atttypmod)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("child table \"%s\" has different type for column \"%s\"",
RelationGetRelationName(child_rel),
attributeName)));
if (attribute->attcollation != childatt->attcollation)
ereport(ERROR,
(errcode(ERRCODE_COLLATION_MISMATCH),
errmsg("child table \"%s\" has different collation for column \"%s\"",
RelationGetRelationName(child_rel),
attributeName)));
/*
* Check child doesn't discard NOT NULL property. (Other
* constraints are checked elsewhere.)
*/
if (attribute->attnotnull && !childatt->attnotnull)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("column \"%s\" in child table must be marked NOT NULL",
attributeName)));
/*
* OK, bump the child column's inheritance count. (If we fail
* later on, this change will just roll back.)
*/
childatt->attinhcount++;
/*
* In case of partitions, we must enforce that value of attislocal
* is same in all partitions. (Note: there are only inherited
* attributes in partitions)
*/
if (child_is_partition)
{
Assert(childatt->attinhcount == 1);
childatt->attislocal = false;
}
CatalogTupleUpdate(attrrel, &tuple->t_self, tuple);
heap_freetuple(tuple);
}
else
{
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("child table is missing column \"%s\"",
attributeName)));
}
}
table_close(attrrel, RowExclusiveLock);
}
/*
* Check constraints in child table match up with constraints in parent,
* and increment their coninhcount.
*
* Constraints that are marked ONLY in the parent are ignored.
*
* Called by CreateInheritance
*
* Currently all constraints in parent must be present in the child. One day we
* may consider adding new constraints like CREATE TABLE does.
*
* XXX This is O(N^2) which may be an issue with tables with hundreds of
* constraints. As long as tables have more like 10 constraints it shouldn't be
* a problem though. Even 100 constraints ought not be the end of the world.
*
* XXX See MergeWithExistingConstraint too if you change this code.
*/
static void
MergeConstraintsIntoExisting(Relation child_rel, Relation parent_rel)
{
Relation catalog_relation;
TupleDesc tuple_desc;
SysScanDesc parent_scan;
ScanKeyData parent_key;
HeapTuple parent_tuple;
bool child_is_partition = false;
catalog_relation = table_open(ConstraintRelationId, RowExclusiveLock);
tuple_desc = RelationGetDescr(catalog_relation);
/* If parent_rel is a partitioned table, child_rel must be a partition */
if (parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
child_is_partition = true;
/* Outer loop scans through the parent's constraint definitions */
ScanKeyInit(&parent_key,
Anum_pg_constraint_conrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(parent_rel)));
parent_scan = systable_beginscan(catalog_relation, ConstraintRelidTypidNameIndexId,
true, NULL, 1, &parent_key);
while (HeapTupleIsValid(parent_tuple = systable_getnext(parent_scan)))
{
Form_pg_constraint parent_con = (Form_pg_constraint) GETSTRUCT(parent_tuple);
SysScanDesc child_scan;
ScanKeyData child_key;
HeapTuple child_tuple;
bool found = false;
if (parent_con->contype != CONSTRAINT_CHECK)
continue;
/* if the parent's constraint is marked NO INHERIT, it's not inherited */
if (parent_con->connoinherit)
continue;
/* Search for a child constraint matching this one */
ScanKeyInit(&child_key,
Anum_pg_constraint_conrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(child_rel)));
child_scan = systable_beginscan(catalog_relation, ConstraintRelidTypidNameIndexId,
true, NULL, 1, &child_key);
while (HeapTupleIsValid(child_tuple = systable_getnext(child_scan)))
{
Form_pg_constraint child_con = (Form_pg_constraint) GETSTRUCT(child_tuple);
HeapTuple child_copy;
if (child_con->contype != CONSTRAINT_CHECK)
continue;
if (strcmp(NameStr(parent_con->conname),
NameStr(child_con->conname)) != 0)
continue;
if (!constraints_equivalent(parent_tuple, child_tuple, tuple_desc))
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("child table \"%s\" has different definition for check constraint \"%s\"",
RelationGetRelationName(child_rel),
NameStr(parent_con->conname))));
/* If the child constraint is "no inherit" then cannot merge */
if (child_con->connoinherit)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("constraint \"%s\" conflicts with non-inherited constraint on child table \"%s\"",
NameStr(child_con->conname),
RelationGetRelationName(child_rel))));
/*
* If the child constraint is "not valid" then cannot merge with a
* valid parent constraint
*/
if (parent_con->convalidated && !child_con->convalidated)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("constraint \"%s\" conflicts with NOT VALID constraint on child table \"%s\"",
NameStr(child_con->conname),
RelationGetRelationName(child_rel))));
/*
* OK, bump the child constraint's inheritance count. (If we fail
* later on, this change will just roll back.)
*/
child_copy = heap_copytuple(child_tuple);
child_con = (Form_pg_constraint) GETSTRUCT(child_copy);
child_con->coninhcount++;
/*
* In case of partitions, an inherited constraint must be
* inherited only once since it cannot have multiple parents and
* it is never considered local.
*/
if (child_is_partition)
{
Assert(child_con->coninhcount == 1);
child_con->conislocal = false;
}
CatalogTupleUpdate(catalog_relation, &child_copy->t_self, child_copy);
heap_freetuple(child_copy);
found = true;
break;
}
systable_endscan(child_scan);
if (!found)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("child table is missing constraint \"%s\"",
NameStr(parent_con->conname))));
}
systable_endscan(parent_scan);
table_close(catalog_relation, RowExclusiveLock);
}
/*
* ALTER TABLE NO INHERIT
*
* Return value is the address of the relation that is no longer parent.
*/
static ObjectAddress
ATExecDropInherit(Relation rel, RangeVar *parent, LOCKMODE lockmode)
{
ObjectAddress address;
Relation parent_rel;
if (rel->rd_rel->relispartition)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot change inheritance of a partition")));
/*
* AccessShareLock on the parent is probably enough, seeing that DROP
* TABLE doesn't lock parent tables at all. We need some lock since we'll
* be inspecting the parent's schema.
*/
parent_rel = table_openrv(parent, AccessShareLock);
/*
* We don't bother to check ownership of the parent table --- ownership of
* the child is presumed enough rights.
*/
/* Off to RemoveInheritance() where most of the work happens */
RemoveInheritance(rel, parent_rel);
ObjectAddressSet(address, RelationRelationId,
RelationGetRelid(parent_rel));
/* keep our lock on the parent relation until commit */
table_close(parent_rel, NoLock);
return address;
}
/*
* RemoveInheritance
*
* Drop a parent from the child's parents. This just adjusts the attinhcount
* and attislocal of the columns and removes the pg_inherit and pg_depend
* entries.
*
* If attinhcount goes to 0 then attislocal gets set to true. If it goes back
* up attislocal stays true, which means if a child is ever removed from a
* parent then its columns will never be automatically dropped which may
* surprise. But at least we'll never surprise by dropping columns someone
* isn't expecting to be dropped which would actually mean data loss.
*
* coninhcount and conislocal for inherited constraints are adjusted in
* exactly the same way.
*
* Common to ATExecDropInherit() and ATExecDetachPartition().
*/
static void
RemoveInheritance(Relation child_rel, Relation parent_rel)
{
Relation catalogRelation;
SysScanDesc scan;
ScanKeyData key[3];
HeapTuple attributeTuple,
constraintTuple;
List *connames;
bool found;
bool child_is_partition = false;
/* If parent_rel is a partitioned table, child_rel must be a partition */
if (parent_rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
child_is_partition = true;
found = DeleteInheritsTuple(RelationGetRelid(child_rel),
RelationGetRelid(parent_rel));
if (!found)
{
if (child_is_partition)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_TABLE),
errmsg("relation \"%s\" is not a partition of relation \"%s\"",
RelationGetRelationName(child_rel),
RelationGetRelationName(parent_rel))));
else
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_TABLE),
errmsg("relation \"%s\" is not a parent of relation \"%s\"",
RelationGetRelationName(parent_rel),
RelationGetRelationName(child_rel))));
}
/*
* Search through child columns looking for ones matching parent rel
*/
catalogRelation = table_open(AttributeRelationId, RowExclusiveLock);
ScanKeyInit(&key[0],
Anum_pg_attribute_attrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(child_rel)));
scan = systable_beginscan(catalogRelation, AttributeRelidNumIndexId,
true, NULL, 1, key);
while (HeapTupleIsValid(attributeTuple = systable_getnext(scan)))
{
Form_pg_attribute att = (Form_pg_attribute) GETSTRUCT(attributeTuple);
/* Ignore if dropped or not inherited */
if (att->attisdropped)
continue;
if (att->attinhcount <= 0)
continue;
if (SearchSysCacheExistsAttName(RelationGetRelid(parent_rel),
NameStr(att->attname)))
{
/* Decrement inhcount and possibly set islocal to true */
HeapTuple copyTuple = heap_copytuple(attributeTuple);
Form_pg_attribute copy_att = (Form_pg_attribute) GETSTRUCT(copyTuple);
copy_att->attinhcount--;
if (copy_att->attinhcount == 0)
copy_att->attislocal = true;
CatalogTupleUpdate(catalogRelation, &copyTuple->t_self, copyTuple);
heap_freetuple(copyTuple);
}
}
systable_endscan(scan);
table_close(catalogRelation, RowExclusiveLock);
/*
* Likewise, find inherited check constraints and disinherit them. To do
* this, we first need a list of the names of the parent's check
* constraints. (We cheat a bit by only checking for name matches,
* assuming that the expressions will match.)
*/
catalogRelation = table_open(ConstraintRelationId, RowExclusiveLock);
ScanKeyInit(&key[0],
Anum_pg_constraint_conrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(parent_rel)));
scan = systable_beginscan(catalogRelation, ConstraintRelidTypidNameIndexId,
true, NULL, 1, key);
connames = NIL;
while (HeapTupleIsValid(constraintTuple = systable_getnext(scan)))
{
Form_pg_constraint con = (Form_pg_constraint) GETSTRUCT(constraintTuple);
if (con->contype == CONSTRAINT_CHECK)
connames = lappend(connames, pstrdup(NameStr(con->conname)));
}
systable_endscan(scan);
/* Now scan the child's constraints */
ScanKeyInit(&key[0],
Anum_pg_constraint_conrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(child_rel)));
scan = systable_beginscan(catalogRelation, ConstraintRelidTypidNameIndexId,
true, NULL, 1, key);
while (HeapTupleIsValid(constraintTuple = systable_getnext(scan)))
{
Form_pg_constraint con = (Form_pg_constraint) GETSTRUCT(constraintTuple);
bool match;
ListCell *lc;
if (con->contype != CONSTRAINT_CHECK)
continue;
match = false;
foreach(lc, connames)
{
if (strcmp(NameStr(con->conname), (char *) lfirst(lc)) == 0)
{
match = true;
break;
}
}
if (match)
{
/* Decrement inhcount and possibly set islocal to true */
HeapTuple copyTuple = heap_copytuple(constraintTuple);
Form_pg_constraint copy_con = (Form_pg_constraint) GETSTRUCT(copyTuple);
if (copy_con->coninhcount <= 0) /* shouldn't happen */
elog(ERROR, "relation %u has non-inherited constraint \"%s\"",
RelationGetRelid(child_rel), NameStr(copy_con->conname));
copy_con->coninhcount--;
if (copy_con->coninhcount == 0)
copy_con->conislocal = true;
CatalogTupleUpdate(catalogRelation, &copyTuple->t_self, copyTuple);
heap_freetuple(copyTuple);
}
}
systable_endscan(scan);
table_close(catalogRelation, RowExclusiveLock);
drop_parent_dependency(RelationGetRelid(child_rel),
RelationRelationId,
RelationGetRelid(parent_rel),
child_dependency_type(child_is_partition));
/*
* Post alter hook of this inherits. Since object_access_hook doesn't take
* multiple object identifiers, we relay oid of parent relation using
* auxiliary_id argument.
*/
InvokeObjectPostAlterHookArg(InheritsRelationId,
RelationGetRelid(child_rel), 0,
RelationGetRelid(parent_rel), false);
}
/*
* Drop the dependency created by StoreCatalogInheritance1 (CREATE TABLE
* INHERITS/ALTER TABLE INHERIT -- refclassid will be RelationRelationId) or
* heap_create_with_catalog (CREATE TABLE OF/ALTER TABLE OF -- refclassid will
* be TypeRelationId). There's no convenient way to do this, so go trawling
* through pg_depend.
*/
static void
drop_parent_dependency(Oid relid, Oid refclassid, Oid refobjid,
DependencyType deptype)
{
Relation catalogRelation;
SysScanDesc scan;
ScanKeyData key[3];
HeapTuple depTuple;
catalogRelation = table_open(DependRelationId, RowExclusiveLock);
ScanKeyInit(&key[0],
Anum_pg_depend_classid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationRelationId));
ScanKeyInit(&key[1],
Anum_pg_depend_objid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(relid));
ScanKeyInit(&key[2],
Anum_pg_depend_objsubid,
BTEqualStrategyNumber, F_INT4EQ,
Int32GetDatum(0));
scan = systable_beginscan(catalogRelation, DependDependerIndexId, true,
NULL, 3, key);
while (HeapTupleIsValid(depTuple = systable_getnext(scan)))
{
Form_pg_depend dep = (Form_pg_depend) GETSTRUCT(depTuple);
if (dep->refclassid == refclassid &&
dep->refobjid == refobjid &&
dep->refobjsubid == 0 &&
dep->deptype == deptype)
CatalogTupleDelete(catalogRelation, &depTuple->t_self);
}
systable_endscan(scan);
table_close(catalogRelation, RowExclusiveLock);
}
/*
* ALTER TABLE OF
*
* Attach a table to a composite type, as though it had been created with CREATE
* TABLE OF. All attname, atttypid, atttypmod and attcollation must match. The
* subject table must not have inheritance parents. These restrictions ensure
* that you cannot create a configuration impossible with CREATE TABLE OF alone.
*
* The address of the type is returned.
*/
static ObjectAddress
ATExecAddOf(Relation rel, const TypeName *ofTypename, LOCKMODE lockmode)
{
Oid relid = RelationGetRelid(rel);
Type typetuple;
Form_pg_type typeform;
Oid typeid;
Relation inheritsRelation,
relationRelation;
SysScanDesc scan;
ScanKeyData key;
AttrNumber table_attno,
type_attno;
TupleDesc typeTupleDesc,
tableTupleDesc;
ObjectAddress tableobj,
typeobj;
HeapTuple classtuple;
/* Validate the type. */
typetuple = typenameType(NULL, ofTypename, NULL);
check_of_type(typetuple);
typeform = (Form_pg_type) GETSTRUCT(typetuple);
typeid = typeform->oid;
/* Fail if the table has any inheritance parents. */
inheritsRelation = table_open(InheritsRelationId, AccessShareLock);
ScanKeyInit(&key,
Anum_pg_inherits_inhrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(relid));
scan = systable_beginscan(inheritsRelation, InheritsRelidSeqnoIndexId,
true, NULL, 1, &key);
if (HeapTupleIsValid(systable_getnext(scan)))
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("typed tables cannot inherit")));
systable_endscan(scan);
table_close(inheritsRelation, AccessShareLock);
/*
* Check the tuple descriptors for compatibility. Unlike inheritance, we
* require that the order also match. However, attnotnull need not match.
*/
typeTupleDesc = lookup_rowtype_tupdesc(typeid, -1);
tableTupleDesc = RelationGetDescr(rel);
table_attno = 1;
for (type_attno = 1; type_attno <= typeTupleDesc->natts; type_attno++)
{
Form_pg_attribute type_attr,
table_attr;
const char *type_attname,
*table_attname;
/* Get the next non-dropped type attribute. */
type_attr = TupleDescAttr(typeTupleDesc, type_attno - 1);
if (type_attr->attisdropped)
continue;
type_attname = NameStr(type_attr->attname);
/* Get the next non-dropped table attribute. */
do
{
if (table_attno > tableTupleDesc->natts)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("table is missing column \"%s\"",
type_attname)));
table_attr = TupleDescAttr(tableTupleDesc, table_attno - 1);
table_attno++;
} while (table_attr->attisdropped);
table_attname = NameStr(table_attr->attname);
/* Compare name. */
if (strncmp(table_attname, type_attname, NAMEDATALEN) != 0)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("table has column \"%s\" where type requires \"%s\"",
table_attname, type_attname)));
/* Compare type. */
if (table_attr->atttypid != type_attr->atttypid ||
table_attr->atttypmod != type_attr->atttypmod ||
table_attr->attcollation != type_attr->attcollation)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("table \"%s\" has different type for column \"%s\"",
RelationGetRelationName(rel), type_attname)));
}
DecrTupleDescRefCount(typeTupleDesc);
/* Any remaining columns at the end of the table had better be dropped. */
for (; table_attno <= tableTupleDesc->natts; table_attno++)
{
Form_pg_attribute table_attr = TupleDescAttr(tableTupleDesc,
table_attno - 1);
if (!table_attr->attisdropped)
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("table has extra column \"%s\"",
NameStr(table_attr->attname))));
}
/* If the table was already typed, drop the existing dependency. */
if (rel->rd_rel->reloftype)
drop_parent_dependency(relid, TypeRelationId, rel->rd_rel->reloftype,
DEPENDENCY_NORMAL);
/* Record a dependency on the new type. */
tableobj.classId = RelationRelationId;
tableobj.objectId = relid;
tableobj.objectSubId = 0;
typeobj.classId = TypeRelationId;
typeobj.objectId = typeid;
typeobj.objectSubId = 0;
recordDependencyOn(&tableobj, &typeobj, DEPENDENCY_NORMAL);
/* Update pg_class.reloftype */
relationRelation = table_open(RelationRelationId, RowExclusiveLock);
classtuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
if (!HeapTupleIsValid(classtuple))
elog(ERROR, "cache lookup failed for relation %u", relid);
((Form_pg_class) GETSTRUCT(classtuple))->reloftype = typeid;
CatalogTupleUpdate(relationRelation, &classtuple->t_self, classtuple);
InvokeObjectPostAlterHook(RelationRelationId, relid, 0);
heap_freetuple(classtuple);
table_close(relationRelation, RowExclusiveLock);
ReleaseSysCache(typetuple);
return typeobj;
}
/*
* ALTER TABLE NOT OF
*
* Detach a typed table from its originating type. Just clear reloftype and
* remove the dependency.
*/
static void
ATExecDropOf(Relation rel, LOCKMODE lockmode)
{
Oid relid = RelationGetRelid(rel);
Relation relationRelation;
HeapTuple tuple;
if (!OidIsValid(rel->rd_rel->reloftype))
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a typed table",
RelationGetRelationName(rel))));
/*
* We don't bother to check ownership of the type --- ownership of the
* table is presumed enough rights. No lock required on the type, either.
*/
drop_parent_dependency(relid, TypeRelationId, rel->rd_rel->reloftype,
DEPENDENCY_NORMAL);
/* Clear pg_class.reloftype */
relationRelation = table_open(RelationRelationId, RowExclusiveLock);
tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for relation %u", relid);
((Form_pg_class) GETSTRUCT(tuple))->reloftype = InvalidOid;
CatalogTupleUpdate(relationRelation, &tuple->t_self, tuple);
InvokeObjectPostAlterHook(RelationRelationId, relid, 0);
heap_freetuple(tuple);
table_close(relationRelation, RowExclusiveLock);
}
/*
* relation_mark_replica_identity: Update a table's replica identity
*
* Iff ri_type = REPLICA_IDENTITY_INDEX, indexOid must be the Oid of a suitable
* index. Otherwise, it should be InvalidOid.
*/
static void
relation_mark_replica_identity(Relation rel, char ri_type, Oid indexOid,
bool is_internal)
{
Relation pg_index;
Relation pg_class;
HeapTuple pg_class_tuple;
HeapTuple pg_index_tuple;
Form_pg_class pg_class_form;
Form_pg_index pg_index_form;
ListCell *index;
/*
* Check whether relreplident has changed, and update it if so.
*/
pg_class = table_open(RelationRelationId, RowExclusiveLock);
pg_class_tuple = SearchSysCacheCopy1(RELOID,
ObjectIdGetDatum(RelationGetRelid(rel)));
if (!HeapTupleIsValid(pg_class_tuple))
elog(ERROR, "cache lookup failed for relation \"%s\"",
RelationGetRelationName(rel));
pg_class_form = (Form_pg_class) GETSTRUCT(pg_class_tuple);
if (pg_class_form->relreplident != ri_type)
{
pg_class_form->relreplident = ri_type;
CatalogTupleUpdate(pg_class, &pg_class_tuple->t_self, pg_class_tuple);
}
table_close(pg_class, RowExclusiveLock);
heap_freetuple(pg_class_tuple);
/*
* Check whether the correct index is marked indisreplident; if so, we're
* done.
*/
if (OidIsValid(indexOid))
{
Assert(ri_type == REPLICA_IDENTITY_INDEX);
pg_index_tuple = SearchSysCache1(INDEXRELID, ObjectIdGetDatum(indexOid));
if (!HeapTupleIsValid(pg_index_tuple))
elog(ERROR, "cache lookup failed for index %u", indexOid);
pg_index_form = (Form_pg_index) GETSTRUCT(pg_index_tuple);
if (pg_index_form->indisreplident)
{
ReleaseSysCache(pg_index_tuple);
return;
}
ReleaseSysCache(pg_index_tuple);
}
/*
* Clear the indisreplident flag from any index that had it previously,
* and set it for any index that should have it now.
*/
pg_index = table_open(IndexRelationId, RowExclusiveLock);
foreach(index, RelationGetIndexList(rel))
{
Oid thisIndexOid = lfirst_oid(index);
bool dirty = false;
pg_index_tuple = SearchSysCacheCopy1(INDEXRELID,
ObjectIdGetDatum(thisIndexOid));
if (!HeapTupleIsValid(pg_index_tuple))
elog(ERROR, "cache lookup failed for index %u", thisIndexOid);
pg_index_form = (Form_pg_index) GETSTRUCT(pg_index_tuple);
/*
* Unset the bit if set. We know it's wrong because we checked this
* earlier.
*/
if (pg_index_form->indisreplident)
{
dirty = true;
pg_index_form->indisreplident = false;
}
else if (thisIndexOid == indexOid)
{
dirty = true;
pg_index_form->indisreplident = true;
}
if (dirty)
{
CatalogTupleUpdate(pg_index, &pg_index_tuple->t_self, pg_index_tuple);
InvokeObjectPostAlterHookArg(IndexRelationId, thisIndexOid, 0,
InvalidOid, is_internal);
}
heap_freetuple(pg_index_tuple);
}
table_close(pg_index, RowExclusiveLock);
}
/*
* ALTER TABLE <name> REPLICA IDENTITY ...
*/
static void
ATExecReplicaIdentity(Relation rel, ReplicaIdentityStmt *stmt, LOCKMODE lockmode)
{
Oid indexOid;
Relation indexRel;
int key;
if (stmt->identity_type == REPLICA_IDENTITY_DEFAULT)
{
relation_mark_replica_identity(rel, stmt->identity_type, InvalidOid, true);
return;
}
else if (stmt->identity_type == REPLICA_IDENTITY_FULL)
{
relation_mark_replica_identity(rel, stmt->identity_type, InvalidOid, true);
return;
}
else if (stmt->identity_type == REPLICA_IDENTITY_NOTHING)
{
relation_mark_replica_identity(rel, stmt->identity_type, InvalidOid, true);
return;
}
else if (stmt->identity_type == REPLICA_IDENTITY_INDEX)
{
/* fallthrough */ ;
}
else
elog(ERROR, "unexpected identity type %u", stmt->identity_type);
/* Check that the index exists */
indexOid = get_relname_relid(stmt->name, rel->rd_rel->relnamespace);
if (!OidIsValid(indexOid))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("index \"%s\" for table \"%s\" does not exist",
stmt->name, RelationGetRelationName(rel))));
indexRel = index_open(indexOid, ShareLock);
/* Check that the index is on the relation we're altering. */
if (indexRel->rd_index == NULL ||
indexRel->rd_index->indrelid != RelationGetRelid(rel))
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not an index for table \"%s\"",
RelationGetRelationName(indexRel),
RelationGetRelationName(rel))));
/* The AM must support uniqueness, and the index must in fact be unique. */
if (!indexRel->rd_indam->amcanunique ||
!indexRel->rd_index->indisunique)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot use non-unique index \"%s\" as replica identity",
RelationGetRelationName(indexRel))));
/* Deferred indexes are not guaranteed to be always unique. */
if (!indexRel->rd_index->indimmediate)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot use non-immediate index \"%s\" as replica identity",
RelationGetRelationName(indexRel))));
/* Expression indexes aren't supported. */
if (RelationGetIndexExpressions(indexRel) != NIL)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot use expression index \"%s\" as replica identity",
RelationGetRelationName(indexRel))));
/* Predicate indexes aren't supported. */
if (RelationGetIndexPredicate(indexRel) != NIL)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot use partial index \"%s\" as replica identity",
RelationGetRelationName(indexRel))));
/* And neither are invalid indexes. */
if (!indexRel->rd_index->indisvalid)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot use invalid index \"%s\" as replica identity",
RelationGetRelationName(indexRel))));
/* Check index for nullable columns. */
for (key = 0; key < IndexRelationGetNumberOfKeyAttributes(indexRel); key++)
{
int16 attno = indexRel->rd_index->indkey.values[key];
Form_pg_attribute attr;
/*
* Reject any other system columns. (Going forward, we'll disallow
* indexes containing such columns in the first place, but they might
* exist in older branches.)
*/
if (attno <= 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
errmsg("index \"%s\" cannot be used as replica identity because column %d is a system column",
RelationGetRelationName(indexRel), attno)));
attr = TupleDescAttr(rel->rd_att, attno - 1);
if (!attr->attnotnull)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("index \"%s\" cannot be used as replica identity because column \"%s\" is nullable",
RelationGetRelationName(indexRel),
NameStr(attr->attname))));
}
/* This index is suitable for use as a replica identity. Mark it. */
relation_mark_replica_identity(rel, stmt->identity_type, indexOid, true);
index_close(indexRel, NoLock);
}
/*
* ALTER TABLE ENABLE/DISABLE ROW LEVEL SECURITY
*/
static void
ATExecEnableRowSecurity(Relation rel)
{
Relation pg_class;
Oid relid;
HeapTuple tuple;
relid = RelationGetRelid(rel);
pg_class = table_open(RelationRelationId, RowExclusiveLock);
tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for relation %u", relid);
((Form_pg_class) GETSTRUCT(tuple))->relrowsecurity = true;
CatalogTupleUpdate(pg_class, &tuple->t_self, tuple);
table_close(pg_class, RowExclusiveLock);
heap_freetuple(tuple);
}
static void
ATExecDisableRowSecurity(Relation rel)
{
Relation pg_class;
Oid relid;
HeapTuple tuple;
relid = RelationGetRelid(rel);
/* Pull the record for this relation and update it */
pg_class = table_open(RelationRelationId, RowExclusiveLock);
tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for relation %u", relid);
((Form_pg_class) GETSTRUCT(tuple))->relrowsecurity = false;
CatalogTupleUpdate(pg_class, &tuple->t_self, tuple);
table_close(pg_class, RowExclusiveLock);
heap_freetuple(tuple);
}
/*
* ALTER TABLE FORCE/NO FORCE ROW LEVEL SECURITY
*/
static void
ATExecForceNoForceRowSecurity(Relation rel, bool force_rls)
{
Relation pg_class;
Oid relid;
HeapTuple tuple;
relid = RelationGetRelid(rel);
pg_class = table_open(RelationRelationId, RowExclusiveLock);
tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relid));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for relation %u", relid);
((Form_pg_class) GETSTRUCT(tuple))->relforcerowsecurity = force_rls;
CatalogTupleUpdate(pg_class, &tuple->t_self, tuple);
table_close(pg_class, RowExclusiveLock);
heap_freetuple(tuple);
}
/*
* ALTER FOREIGN TABLE <name> OPTIONS (...)
*/
static void
ATExecGenericOptions(Relation rel, List *options)
{
Relation ftrel;
ForeignServer *server;
ForeignDataWrapper *fdw;
HeapTuple tuple;
bool isnull;
Datum repl_val[Natts_pg_foreign_table];
bool repl_null[Natts_pg_foreign_table];
bool repl_repl[Natts_pg_foreign_table];
Datum datum;
Form_pg_foreign_table tableform;
if (options == NIL)
return;
ftrel = table_open(ForeignTableRelationId, RowExclusiveLock);
tuple = SearchSysCacheCopy1(FOREIGNTABLEREL, rel->rd_id);
if (!HeapTupleIsValid(tuple))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("foreign table \"%s\" does not exist",
RelationGetRelationName(rel))));
tableform = (Form_pg_foreign_table) GETSTRUCT(tuple);
server = GetForeignServer(tableform->ftserver);
fdw = GetForeignDataWrapper(server->fdwid);
memset(repl_val, 0, sizeof(repl_val));
memset(repl_null, false, sizeof(repl_null));
memset(repl_repl, false, sizeof(repl_repl));
/* Extract the current options */
datum = SysCacheGetAttr(FOREIGNTABLEREL,
tuple,
Anum_pg_foreign_table_ftoptions,
&isnull);
if (isnull)
datum = PointerGetDatum(NULL);
/* Transform the options */
datum = transformGenericOptions(ForeignTableRelationId,
datum,
options,
fdw->fdwvalidator);
if (PointerIsValid(DatumGetPointer(datum)))
repl_val[Anum_pg_foreign_table_ftoptions - 1] = datum;
else
repl_null[Anum_pg_foreign_table_ftoptions - 1] = true;
repl_repl[Anum_pg_foreign_table_ftoptions - 1] = true;
/* Everything looks good - update the tuple */
tuple = heap_modify_tuple(tuple, RelationGetDescr(ftrel),
repl_val, repl_null, repl_repl);
CatalogTupleUpdate(ftrel, &tuple->t_self, tuple);
/*
* Invalidate relcache so that all sessions will refresh any cached plans
* that might depend on the old options.
*/
CacheInvalidateRelcache(rel);
InvokeObjectPostAlterHook(ForeignTableRelationId,
RelationGetRelid(rel), 0);
table_close(ftrel, RowExclusiveLock);
heap_freetuple(tuple);
}
/*
* Preparation phase for SET LOGGED/UNLOGGED
*
* This verifies that we're not trying to change a temp table. Also,
* existing foreign key constraints are checked to avoid ending up with
* permanent tables referencing unlogged tables.
*
* Return value is false if the operation is a no-op (in which case the
* checks are skipped), otherwise true.
*/
static bool
ATPrepChangePersistence(Relation rel, bool toLogged)
{
Relation pg_constraint;
HeapTuple tuple;
SysScanDesc scan;
ScanKeyData skey[1];
/*
* Disallow changing status for a temp table. Also verify whether we can
* get away with doing nothing; in such cases we don't need to run the
* checks below, either.
*/
switch (rel->rd_rel->relpersistence)
{
case RELPERSISTENCE_TEMP:
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("cannot change logged status of table \"%s\" because it is temporary",
RelationGetRelationName(rel)),
errtable(rel)));
break;
case RELPERSISTENCE_PERMANENT:
if (toLogged)
/* nothing to do */
return false;
break;
case RELPERSISTENCE_UNLOGGED:
if (!toLogged)
/* nothing to do */
return false;
break;
}
/*
* Check that the table is not part any publication when changing to
* UNLOGGED as UNLOGGED tables can't be published.
*/
if (!toLogged &&
list_length(GetRelationPublications(RelationGetRelid(rel))) > 0)
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("cannot change table \"%s\" to unlogged because it is part of a publication",
RelationGetRelationName(rel)),
errdetail("Unlogged relations cannot be replicated.")));
/*
* Check existing foreign key constraints to preserve the invariant that
* permanent tables cannot reference unlogged ones. Self-referencing
* foreign keys can safely be ignored.
*/
pg_constraint = table_open(ConstraintRelationId, AccessShareLock);
/*
* Scan conrelid if changing to permanent, else confrelid. This also
* determines whether a useful index exists.
*/
ScanKeyInit(&skey[0],
toLogged ? Anum_pg_constraint_conrelid :
Anum_pg_constraint_confrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(rel)));
scan = systable_beginscan(pg_constraint,
toLogged ? ConstraintRelidTypidNameIndexId : InvalidOid,
true, NULL, 1, skey);
while (HeapTupleIsValid(tuple = systable_getnext(scan)))
{
Form_pg_constraint con = (Form_pg_constraint) GETSTRUCT(tuple);
if (con->contype == CONSTRAINT_FOREIGN)
{
Oid foreignrelid;
Relation foreignrel;
/* the opposite end of what we used as scankey */
foreignrelid = toLogged ? con->confrelid : con->conrelid;
/* ignore if self-referencing */
if (RelationGetRelid(rel) == foreignrelid)
continue;
foreignrel = relation_open(foreignrelid, AccessShareLock);
if (toLogged)
{
if (foreignrel->rd_rel->relpersistence != RELPERSISTENCE_PERMANENT)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("could not change table \"%s\" to logged because it references unlogged table \"%s\"",
RelationGetRelationName(rel),
RelationGetRelationName(foreignrel)),
errtableconstraint(rel, NameStr(con->conname))));
}
else
{
if (foreignrel->rd_rel->relpersistence == RELPERSISTENCE_PERMANENT)
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("could not change table \"%s\" to unlogged because it references logged table \"%s\"",
RelationGetRelationName(rel),
RelationGetRelationName(foreignrel)),
errtableconstraint(rel, NameStr(con->conname))));
}
relation_close(foreignrel, AccessShareLock);
}
}
systable_endscan(scan);
table_close(pg_constraint, AccessShareLock);
return true;
}
/*
* Execute ALTER TABLE SET SCHEMA
*/
ObjectAddress
AlterTableNamespace(AlterObjectSchemaStmt *stmt, Oid *oldschema)
{
Relation rel;
Oid relid;
Oid oldNspOid;
Oid nspOid;
RangeVar *newrv;
ObjectAddresses *objsMoved;
ObjectAddress myself;
relid = RangeVarGetRelidExtended(stmt->relation, AccessExclusiveLock,
stmt->missing_ok ? RVR_MISSING_OK : 0,
RangeVarCallbackForAlterRelation,
(void *) stmt);
if (!OidIsValid(relid))
{
ereport(NOTICE,
(errmsg("relation \"%s\" does not exist, skipping",
stmt->relation->relname)));
return InvalidObjectAddress;
}
rel = relation_open(relid, NoLock);
oldNspOid = RelationGetNamespace(rel);
/* If it's an owned sequence, disallow moving it by itself. */
if (rel->rd_rel->relkind == RELKIND_SEQUENCE)
{
Oid tableId;
int32 colId;
if (sequenceIsOwned(relid, DEPENDENCY_AUTO, &tableId, &colId) ||
sequenceIsOwned(relid, DEPENDENCY_INTERNAL, &tableId, &colId))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot move an owned sequence into another schema"),
errdetail("Sequence \"%s\" is linked to table \"%s\".",
RelationGetRelationName(rel),
get_rel_name(tableId))));
}
/* Get and lock schema OID and check its permissions. */
newrv = makeRangeVar(stmt->newschema, RelationGetRelationName(rel), -1);
nspOid = RangeVarGetAndCheckCreationNamespace(newrv, NoLock, NULL);
/* common checks on switching namespaces */
CheckSetNamespace(oldNspOid, nspOid);
objsMoved = new_object_addresses();
AlterTableNamespaceInternal(rel, oldNspOid, nspOid, objsMoved);
free_object_addresses(objsMoved);
ObjectAddressSet(myself, RelationRelationId, relid);
if (oldschema)
*oldschema = oldNspOid;
/* close rel, but keep lock until commit */
relation_close(rel, NoLock);
return myself;
}
/*
* The guts of relocating a table or materialized view to another namespace:
* besides moving the relation itself, its dependent objects are relocated to
* the new schema.
*/
void
AlterTableNamespaceInternal(Relation rel, Oid oldNspOid, Oid nspOid,
ObjectAddresses *objsMoved)
{
Relation classRel;
Assert(objsMoved != NULL);
/* OK, modify the pg_class row and pg_depend entry */
classRel = table_open(RelationRelationId, RowExclusiveLock);
AlterRelationNamespaceInternal(classRel, RelationGetRelid(rel), oldNspOid,
nspOid, true, objsMoved);
/* Fix the table's row type too */
AlterTypeNamespaceInternal(rel->rd_rel->reltype,
nspOid, false, false, objsMoved);
/* Fix other dependent stuff */
if (rel->rd_rel->relkind == RELKIND_RELATION ||
rel->rd_rel->relkind == RELKIND_MATVIEW ||
rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
{
AlterIndexNamespaces(classRel, rel, oldNspOid, nspOid, objsMoved);
AlterSeqNamespaces(classRel, rel, oldNspOid, nspOid,
objsMoved, AccessExclusiveLock);
AlterConstraintNamespaces(RelationGetRelid(rel), oldNspOid, nspOid,
false, objsMoved);
}
table_close(classRel, RowExclusiveLock);
}
/*
* The guts of relocating a relation to another namespace: fix the pg_class
* entry, and the pg_depend entry if any. Caller must already have
* opened and write-locked pg_class.
*/
void
AlterRelationNamespaceInternal(Relation classRel, Oid relOid,
Oid oldNspOid, Oid newNspOid,
bool hasDependEntry,
ObjectAddresses *objsMoved)
{
HeapTuple classTup;
Form_pg_class classForm;
ObjectAddress thisobj;
bool already_done = false;
classTup = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relOid));
if (!HeapTupleIsValid(classTup))
elog(ERROR, "cache lookup failed for relation %u", relOid);
classForm = (Form_pg_class) GETSTRUCT(classTup);
Assert(classForm->relnamespace == oldNspOid);
thisobj.classId = RelationRelationId;
thisobj.objectId = relOid;
thisobj.objectSubId = 0;
/*
* If the object has already been moved, don't move it again. If it's
* already in the right place, don't move it, but still fire the object
* access hook.
*/
already_done = object_address_present(&thisobj, objsMoved);
if (!already_done && oldNspOid != newNspOid)
{
/* check for duplicate name (more friendly than unique-index failure) */
if (get_relname_relid(NameStr(classForm->relname),
newNspOid) != InvalidOid)
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_TABLE),
errmsg("relation \"%s\" already exists in schema \"%s\"",
NameStr(classForm->relname),
get_namespace_name(newNspOid))));
/* classTup is a copy, so OK to scribble on */
classForm->relnamespace = newNspOid;
CatalogTupleUpdate(classRel, &classTup->t_self, classTup);
/* Update dependency on schema if caller said so */
if (hasDependEntry &&
changeDependencyFor(RelationRelationId,
relOid,
NamespaceRelationId,
oldNspOid,
newNspOid) != 1)
elog(ERROR, "failed to change schema dependency for relation \"%s\"",
NameStr(classForm->relname));
}
if (!already_done)
{
add_exact_object_address(&thisobj, objsMoved);
InvokeObjectPostAlterHook(RelationRelationId, relOid, 0);
}
heap_freetuple(classTup);
}
/*
* Move all indexes for the specified relation to another namespace.
*
* Note: we assume adequate permission checking was done by the caller,
* and that the caller has a suitable lock on the owning relation.
*/
static void
AlterIndexNamespaces(Relation classRel, Relation rel,
Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved)
{
List *indexList;
ListCell *l;
indexList = RelationGetIndexList(rel);
foreach(l, indexList)
{
Oid indexOid = lfirst_oid(l);
ObjectAddress thisobj;
thisobj.classId = RelationRelationId;
thisobj.objectId = indexOid;
thisobj.objectSubId = 0;
/*
* Note: currently, the index will not have its own dependency on the
* namespace, so we don't need to do changeDependencyFor(). There's no
* row type in pg_type, either.
*
* XXX this objsMoved test may be pointless -- surely we have a single
* dependency link from a relation to each index?
*/
if (!object_address_present(&thisobj, objsMoved))
{
AlterRelationNamespaceInternal(classRel, indexOid,
oldNspOid, newNspOid,
false, objsMoved);
add_exact_object_address(&thisobj, objsMoved);
}
}
list_free(indexList);
}
/*
* Move all identity and SERIAL-column sequences of the specified relation to another
* namespace.
*
* Note: we assume adequate permission checking was done by the caller,
* and that the caller has a suitable lock on the owning relation.
*/
static void
AlterSeqNamespaces(Relation classRel, Relation rel,
Oid oldNspOid, Oid newNspOid, ObjectAddresses *objsMoved,
LOCKMODE lockmode)
{
Relation depRel;
SysScanDesc scan;
ScanKeyData key[2];
HeapTuple tup;
/*
* SERIAL sequences are those having an auto dependency on one of the
* table's columns (we don't care *which* column, exactly).
*/
depRel = table_open(DependRelationId, AccessShareLock);
ScanKeyInit(&key[0],
Anum_pg_depend_refclassid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationRelationId));
ScanKeyInit(&key[1],
Anum_pg_depend_refobjid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(rel)));
/* we leave refobjsubid unspecified */
scan = systable_beginscan(depRel, DependReferenceIndexId, true,
NULL, 2, key);
while (HeapTupleIsValid(tup = systable_getnext(scan)))
{
Form_pg_depend depForm = (Form_pg_depend) GETSTRUCT(tup);
Relation seqRel;
/* skip dependencies other than auto dependencies on columns */
if (depForm->refobjsubid == 0 ||
depForm->classid != RelationRelationId ||
depForm->objsubid != 0 ||
!(depForm->deptype == DEPENDENCY_AUTO || depForm->deptype == DEPENDENCY_INTERNAL))
continue;
/* Use relation_open just in case it's an index */
seqRel = relation_open(depForm->objid, lockmode);
/* skip non-sequence relations */
if (RelationGetForm(seqRel)->relkind != RELKIND_SEQUENCE)
{
/* No need to keep the lock */
relation_close(seqRel, lockmode);
continue;
}
/* Fix the pg_class and pg_depend entries */
AlterRelationNamespaceInternal(classRel, depForm->objid,
oldNspOid, newNspOid,
true, objsMoved);
/*
* Sequences have entries in pg_type. We need to be careful to move
* them to the new namespace, too.
*/
AlterTypeNamespaceInternal(RelationGetForm(seqRel)->reltype,
newNspOid, false, false, objsMoved);
/* Now we can close it. Keep the lock till end of transaction. */
relation_close(seqRel, NoLock);
}
systable_endscan(scan);
relation_close(depRel, AccessShareLock);
}
/*
* This code supports
* CREATE TEMP TABLE ... ON COMMIT { DROP | PRESERVE ROWS | DELETE ROWS }
*
* Because we only support this for TEMP tables, it's sufficient to remember
* the state in a backend-local data structure.
*/
/*
* Register a newly-created relation's ON COMMIT action.
*/
void
register_on_commit_action(Oid relid, OnCommitAction action)
{
OnCommitItem *oc;
MemoryContext oldcxt;
/*
* We needn't bother registering the relation unless there is an ON COMMIT
* action we need to take.
*/
if (action == ONCOMMIT_NOOP || action == ONCOMMIT_PRESERVE_ROWS)
return;
oldcxt = MemoryContextSwitchTo(CacheMemoryContext);
oc = (OnCommitItem *) palloc(sizeof(OnCommitItem));
oc->relid = relid;
oc->oncommit = action;
oc->creating_subid = GetCurrentSubTransactionId();
oc->deleting_subid = InvalidSubTransactionId;
/*
* We use lcons() here so that ON COMMIT actions are processed in reverse
* order of registration. That might not be essential but it seems
* reasonable.
*/
on_commits = lcons(oc, on_commits);
MemoryContextSwitchTo(oldcxt);
}
/*
* Unregister any ON COMMIT action when a relation is deleted.
*
* Actually, we only mark the OnCommitItem entry as to be deleted after commit.
*/
void
remove_on_commit_action(Oid relid)
{
ListCell *l;
foreach(l, on_commits)
{
OnCommitItem *oc = (OnCommitItem *) lfirst(l);
if (oc->relid == relid)
{
oc->deleting_subid = GetCurrentSubTransactionId();
break;
}
}
}
/*
* Perform ON COMMIT actions.
*
* This is invoked just before actually committing, since it's possible
* to encounter errors.
*/
void
PreCommit_on_commit_actions(void)
{
ListCell *l;
List *oids_to_truncate = NIL;
List *oids_to_drop = NIL;
foreach(l, on_commits)
{
OnCommitItem *oc = (OnCommitItem *) lfirst(l);
/* Ignore entry if already dropped in this xact */
if (oc->deleting_subid != InvalidSubTransactionId)
continue;
switch (oc->oncommit)
{
case ONCOMMIT_NOOP:
case ONCOMMIT_PRESERVE_ROWS:
/* Do nothing (there shouldn't be such entries, actually) */
break;
case ONCOMMIT_DELETE_ROWS:
/*
* If this transaction hasn't accessed any temporary
* relations, we can skip truncating ON COMMIT DELETE ROWS
* tables, as they must still be empty.
*/
if ((MyXactFlags & XACT_FLAGS_ACCESSEDTEMPNAMESPACE))
oids_to_truncate = lappend_oid(oids_to_truncate, oc->relid);
break;
case ONCOMMIT_DROP:
oids_to_drop = lappend_oid(oids_to_drop, oc->relid);
break;
}
}
/*
* Truncate relations before dropping so that all dependencies between
* relations are removed after they are worked on. Doing it like this
* might be a waste as it is possible that a relation being truncated will
* be dropped anyway due to its parent being dropped, but this makes the
* code more robust because of not having to re-check that the relation
* exists at truncation time.
*/
if (oids_to_truncate != NIL)
heap_truncate(oids_to_truncate);
if (oids_to_drop != NIL)
{
ObjectAddresses *targetObjects = new_object_addresses();
ListCell *l;
foreach(l, oids_to_drop)
{
ObjectAddress object;
object.classId = RelationRelationId;
object.objectId = lfirst_oid(l);
object.objectSubId = 0;
Assert(!object_address_present(&object, targetObjects));
add_exact_object_address(&object, targetObjects);
}
/*
* Since this is an automatic drop, rather than one directly initiated
* by the user, we pass the PERFORM_DELETION_INTERNAL flag.
*/
performMultipleDeletions(targetObjects, DROP_CASCADE,
PERFORM_DELETION_INTERNAL | PERFORM_DELETION_QUIETLY);
#ifdef USE_ASSERT_CHECKING
/*
* Note that table deletion will call remove_on_commit_action, so the
* entry should get marked as deleted.
*/
foreach(l, on_commits)
{
OnCommitItem *oc = (OnCommitItem *) lfirst(l);
if (oc->oncommit != ONCOMMIT_DROP)
continue;
Assert(oc->deleting_subid != InvalidSubTransactionId);
}
#endif
}
}
/*
* Post-commit or post-abort cleanup for ON COMMIT management.
*
* All we do here is remove no-longer-needed OnCommitItem entries.
*
* During commit, remove entries that were deleted during this transaction;
* during abort, remove those created during this transaction.
*/
void
AtEOXact_on_commit_actions(bool isCommit)
{
ListCell *cur_item;
foreach(cur_item, on_commits)
{
OnCommitItem *oc = (OnCommitItem *) lfirst(cur_item);
if (isCommit ? oc->deleting_subid != InvalidSubTransactionId :
oc->creating_subid != InvalidSubTransactionId)
{
/* cur_item must be removed */
on_commits = foreach_delete_current(on_commits, cur_item);
pfree(oc);
}
else
{
/* cur_item must be preserved */
oc->creating_subid = InvalidSubTransactionId;
oc->deleting_subid = InvalidSubTransactionId;
}
}
}
/*
* Post-subcommit or post-subabort cleanup for ON COMMIT management.
*
* During subabort, we can immediately remove entries created during this
* subtransaction. During subcommit, just relabel entries marked during
* this subtransaction as being the parent's responsibility.
*/
void
AtEOSubXact_on_commit_actions(bool isCommit, SubTransactionId mySubid,
SubTransactionId parentSubid)
{
ListCell *cur_item;
foreach(cur_item, on_commits)
{
OnCommitItem *oc = (OnCommitItem *) lfirst(cur_item);
if (!isCommit && oc->creating_subid == mySubid)
{
/* cur_item must be removed */
on_commits = foreach_delete_current(on_commits, cur_item);
pfree(oc);
}
else
{
/* cur_item must be preserved */
if (oc->creating_subid == mySubid)
oc->creating_subid = parentSubid;
if (oc->deleting_subid == mySubid)
oc->deleting_subid = isCommit ? parentSubid : InvalidSubTransactionId;
}
}
}
/*
* This is intended as a callback for RangeVarGetRelidExtended(). It allows
* the relation to be locked only if (1) it's a plain table, materialized
* view, or TOAST table and (2) the current user is the owner (or the
* superuser). This meets the permission-checking needs of CLUSTER, REINDEX
* TABLE, and REFRESH MATERIALIZED VIEW; we expose it here so that it can be
* used by all.
*/
void
RangeVarCallbackOwnsTable(const RangeVar *relation,
Oid relId, Oid oldRelId, void *arg)
{
char relkind;
/* Nothing to do if the relation was not found. */
if (!OidIsValid(relId))
return;
/*
* If the relation does exist, check whether it's an index. But note that
* the relation might have been dropped between the time we did the name
* lookup and now. In that case, there's nothing to do.
*/
relkind = get_rel_relkind(relId);
if (!relkind)
return;
if (relkind != RELKIND_RELATION && relkind != RELKIND_TOASTVALUE &&
relkind != RELKIND_MATVIEW && relkind != RELKIND_PARTITIONED_TABLE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a table or materialized view", relation->relname)));
/* Check permissions */
if (!pg_class_ownercheck(relId, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(relId)), relation->relname);
}
/*
* Callback to RangeVarGetRelidExtended() for TRUNCATE processing.
*/
static void
RangeVarCallbackForTruncate(const RangeVar *relation,
Oid relId, Oid oldRelId, void *arg)
{
HeapTuple tuple;
/* Nothing to do if the relation was not found. */
if (!OidIsValid(relId))
return;
tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relId));
if (!HeapTupleIsValid(tuple)) /* should not happen */
elog(ERROR, "cache lookup failed for relation %u", relId);
truncate_check_rel(relId, (Form_pg_class) GETSTRUCT(tuple));
ReleaseSysCache(tuple);
}
/*
* Callback to RangeVarGetRelidExtended(), similar to
* RangeVarCallbackOwnsTable() but without checks on the type of the relation.
*/
void
RangeVarCallbackOwnsRelation(const RangeVar *relation,
Oid relId, Oid oldRelId, void *arg)
{
HeapTuple tuple;
/* Nothing to do if the relation was not found. */
if (!OidIsValid(relId))
return;
tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relId));
if (!HeapTupleIsValid(tuple)) /* should not happen */
elog(ERROR, "cache lookup failed for relation %u", relId);
if (!pg_class_ownercheck(relId, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(relId)),
relation->relname);
if (!allowSystemTableMods &&
IsSystemClass(relId, (Form_pg_class) GETSTRUCT(tuple)))
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("permission denied: \"%s\" is a system catalog",
relation->relname)));
ReleaseSysCache(tuple);
}
/*
* Common RangeVarGetRelid callback for rename, set schema, and alter table
* processing.
*/
static void
RangeVarCallbackForAlterRelation(const RangeVar *rv, Oid relid, Oid oldrelid,
void *arg)
{
Node *stmt = (Node *) arg;
ObjectType reltype;
HeapTuple tuple;
Form_pg_class classform;
AclResult aclresult;
char relkind;
tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
if (!HeapTupleIsValid(tuple))
return; /* concurrently dropped */
classform = (Form_pg_class) GETSTRUCT(tuple);
relkind = classform->relkind;
/* Must own relation. */
if (!pg_class_ownercheck(relid, GetUserId()))
aclcheck_error(ACLCHECK_NOT_OWNER, get_relkind_objtype(get_rel_relkind(relid)), rv->relname);
/* No system table modifications unless explicitly allowed. */
if (!allowSystemTableMods && IsSystemClass(relid, classform))
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("permission denied: \"%s\" is a system catalog",
rv->relname)));
/*
* Extract the specified relation type from the statement parse tree.
*
* Also, for ALTER .. RENAME, check permissions: the user must (still)
* have CREATE rights on the containing namespace.
*/
if (IsA(stmt, RenameStmt))
{
aclresult = pg_namespace_aclcheck(classform->relnamespace,
GetUserId(), ACL_CREATE);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, OBJECT_SCHEMA,
get_namespace_name(classform->relnamespace));
reltype = ((RenameStmt *) stmt)->renameType;
}
else if (IsA(stmt, AlterObjectSchemaStmt))
reltype = ((AlterObjectSchemaStmt *) stmt)->objectType;
else if (IsA(stmt, AlterTableStmt))
reltype = ((AlterTableStmt *) stmt)->relkind;
else
{
elog(ERROR, "unrecognized node type: %d", (int) nodeTag(stmt));
reltype = OBJECT_TABLE; /* placate compiler */
}
/*
* For compatibility with prior releases, we allow ALTER TABLE to be used
* with most other types of relations (but not composite types). We allow
* similar flexibility for ALTER INDEX in the case of RENAME, but not
* otherwise. Otherwise, the user must select the correct form of the
* command for the relation at issue.
*/
if (reltype == OBJECT_SEQUENCE && relkind != RELKIND_SEQUENCE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a sequence", rv->relname)));
if (reltype == OBJECT_VIEW && relkind != RELKIND_VIEW)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a view", rv->relname)));
if (reltype == OBJECT_MATVIEW && relkind != RELKIND_MATVIEW)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a materialized view", rv->relname)));
if (reltype == OBJECT_FOREIGN_TABLE && relkind != RELKIND_FOREIGN_TABLE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a foreign table", rv->relname)));
if (reltype == OBJECT_TYPE && relkind != RELKIND_COMPOSITE_TYPE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a composite type", rv->relname)));
if (reltype == OBJECT_INDEX && relkind != RELKIND_INDEX &&
relkind != RELKIND_PARTITIONED_INDEX
&& !IsA(stmt, RenameStmt))
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not an index", rv->relname)));
/*
* Don't allow ALTER TABLE on composite types. We want people to use ALTER
* TYPE for that.
*/
if (reltype != OBJECT_TYPE && relkind == RELKIND_COMPOSITE_TYPE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is a composite type", rv->relname),
errhint("Use ALTER TYPE instead.")));
/*
* Don't allow ALTER TABLE .. SET SCHEMA on relations that can't be moved
* to a different schema, such as indexes and TOAST tables.
*/
if (IsA(stmt, AlterObjectSchemaStmt) &&
relkind != RELKIND_RELATION &&
relkind != RELKIND_VIEW &&
relkind != RELKIND_MATVIEW &&
relkind != RELKIND_SEQUENCE &&
relkind != RELKIND_FOREIGN_TABLE &&
relkind != RELKIND_PARTITIONED_TABLE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a table, view, materialized view, sequence, or foreign table",
rv->relname)));
ReleaseSysCache(tuple);
}
/*
* Transform any expressions present in the partition key
*
* Returns a transformed PartitionSpec, as well as the strategy code
*/
static PartitionSpec *
transformPartitionSpec(Relation rel, PartitionSpec *partspec, char *strategy)
{
PartitionSpec *newspec;
ParseState *pstate;
RangeTblEntry *rte;
ListCell *l;
newspec = makeNode(PartitionSpec);
newspec->strategy = partspec->strategy;
newspec->partParams = NIL;
newspec->location = partspec->location;
/* Parse partitioning strategy name */
if (pg_strcasecmp(partspec->strategy, "hash") == 0)
*strategy = PARTITION_STRATEGY_HASH;
else if (pg_strcasecmp(partspec->strategy, "list") == 0)
*strategy = PARTITION_STRATEGY_LIST;
else if (pg_strcasecmp(partspec->strategy, "range") == 0)
*strategy = PARTITION_STRATEGY_RANGE;
else
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unrecognized partitioning strategy \"%s\"",
partspec->strategy)));
/* Check valid number of columns for strategy */
if (*strategy == PARTITION_STRATEGY_LIST &&
list_length(partspec->partParams) != 1)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("cannot use \"list\" partition strategy with more than one column")));
/*
* Create a dummy ParseState and insert the target relation as its sole
* rangetable entry. We need a ParseState for transformExpr.
*/
pstate = make_parsestate(NULL);
rte = addRangeTableEntryForRelation(pstate, rel, AccessShareLock,
NULL, false, true);
addRTEtoQuery(pstate, rte, true, true, true);
/* take care of any partition expressions */
foreach(l, partspec->partParams)
{
PartitionElem *pelem = castNode(PartitionElem, lfirst(l));
if (pelem->expr)
{
/* Copy, to avoid scribbling on the input */
pelem = copyObject(pelem);
/* Now do parse transformation of the expression */
pelem->expr = transformExpr(pstate, pelem->expr,
EXPR_KIND_PARTITION_EXPRESSION);
/* we have to fix its collations too */
assign_expr_collations(pstate, pelem->expr);
}
newspec->partParams = lappend(newspec->partParams, pelem);
}
return newspec;
}
/*
* Compute per-partition-column information from a list of PartitionElems.
* Expressions in the PartitionElems must be parse-analyzed already.
*/
static void
ComputePartitionAttrs(ParseState *pstate, Relation rel, List *partParams, AttrNumber *partattrs,
List **partexprs, Oid *partopclass, Oid *partcollation,
char strategy)
{
int attn;
ListCell *lc;
Oid am_oid;
attn = 0;
foreach(lc, partParams)
{
PartitionElem *pelem = castNode(PartitionElem, lfirst(lc));
Oid atttype;
Oid attcollation;
if (pelem->name != NULL)
{
/* Simple attribute reference */
HeapTuple atttuple;
Form_pg_attribute attform;
atttuple = SearchSysCacheAttName(RelationGetRelid(rel),
pelem->name);
if (!HeapTupleIsValid(atttuple))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_COLUMN),
errmsg("column \"%s\" named in partition key does not exist",
pelem->name),
parser_errposition(pstate, pelem->location)));
attform = (Form_pg_attribute) GETSTRUCT(atttuple);
if (attform->attnum <= 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("cannot use system column \"%s\" in partition key",
pelem->name),
parser_errposition(pstate, pelem->location)));
/*
* Generated columns cannot work: They are computed after BEFORE
* triggers, but partition routing is done before all triggers.
*/
if (attform->attgenerated)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("cannot use generated column in partition key"),
errdetail("Column \"%s\" is a generated column.",
pelem->name),
parser_errposition(pstate, pelem->location)));
partattrs[attn] = attform->attnum;
atttype = attform->atttypid;
attcollation = attform->attcollation;
ReleaseSysCache(atttuple);
}
else
{
/* Expression */
Node *expr = pelem->expr;
Assert(expr != NULL);
atttype = exprType(expr);
attcollation = exprCollation(expr);
/*
* Strip any top-level COLLATE clause. This ensures that we treat
* "x COLLATE y" and "(x COLLATE y)" alike.
*/
while (IsA(expr, CollateExpr))
expr = (Node *) ((CollateExpr *) expr)->arg;
if (IsA(expr, Var) &&
((Var *) expr)->varattno > 0)
{
/*
* User wrote "(column)" or "(column COLLATE something)".
* Treat it like simple attribute anyway.
*/
partattrs[attn] = ((Var *) expr)->varattno;
}
else
{
Bitmapset *expr_attrs = NULL;
int i;
partattrs[attn] = 0; /* marks the column as expression */
*partexprs = lappend(*partexprs, expr);
/*
* Try to simplify the expression before checking for
* mutability. The main practical value of doing it in this
* order is that an inline-able SQL-language function will be
* accepted if its expansion is immutable, whether or not the
* function itself is marked immutable.
*
* Note that expression_planner does not change the passed in
* expression destructively and we have already saved the
* expression to be stored into the catalog above.
*/
expr = (Node *) expression_planner((Expr *) expr);
/*
* Partition expression cannot contain mutable functions,
* because a given row must always map to the same partition
* as long as there is no change in the partition boundary
* structure.
*/
if (contain_mutable_functions(expr))
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("functions in partition key expression must be marked IMMUTABLE")));
/*
* transformPartitionSpec() should have already rejected
* subqueries, aggregates, window functions, and SRFs, based
* on the EXPR_KIND_ for partition expressions.
*/
/*
* Cannot have expressions containing whole-row references or
* system column references.
*/
pull_varattnos(expr, 1, &expr_attrs);
if (bms_is_member(0 - FirstLowInvalidHeapAttributeNumber,
expr_attrs))
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("partition key expressions cannot contain whole-row references")));
for (i = FirstLowInvalidHeapAttributeNumber; i < 0; i++)
{
if (bms_is_member(i - FirstLowInvalidHeapAttributeNumber,
expr_attrs))
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("partition key expressions cannot contain system column references")));
}
/*
* Generated columns cannot work: They are computed after
* BEFORE triggers, but partition routing is done before all
* triggers.
*/
i = -1;
while ((i = bms_next_member(expr_attrs, i)) >= 0)
{
AttrNumber attno = i + FirstLowInvalidHeapAttributeNumber;
if (TupleDescAttr(RelationGetDescr(rel), attno - 1)->attgenerated)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("cannot use generated column in partition key"),
errdetail("Column \"%s\" is a generated column.",
get_attname(RelationGetRelid(rel), attno, false)),
parser_errposition(pstate, pelem->location)));
}
/*
* While it is not exactly *wrong* for a partition expression
* to be a constant, it seems better to reject such keys.
*/
if (IsA(expr, Const))
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("cannot use constant expression as partition key")));
}
}
/*
* Apply collation override if any
*/
if (pelem->collation)
attcollation = get_collation_oid(pelem->collation, false);
/*
* Check we have a collation iff it's a collatable type. The only
* expected failures here are (1) COLLATE applied to a noncollatable
* type, or (2) partition expression had an unresolved collation. But
* we might as well code this to be a complete consistency check.
*/
if (type_is_collatable(atttype))
{
if (!OidIsValid(attcollation))
ereport(ERROR,
(errcode(ERRCODE_INDETERMINATE_COLLATION),
errmsg("could not determine which collation to use for partition expression"),
errhint("Use the COLLATE clause to set the collation explicitly.")));
}
else
{
if (OidIsValid(attcollation))
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("collations are not supported by type %s",
format_type_be(atttype))));
}
partcollation[attn] = attcollation;
/*
* Identify the appropriate operator class. For list and range
* partitioning, we use a btree operator class; hash partitioning uses
* a hash operator class.
*/
if (strategy == PARTITION_STRATEGY_HASH)
am_oid = HASH_AM_OID;
else
am_oid = BTREE_AM_OID;
if (!pelem->opclass)
{
partopclass[attn] = GetDefaultOpClass(atttype, am_oid);
if (!OidIsValid(partopclass[attn]))
{
if (strategy == PARTITION_STRATEGY_HASH)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("data type %s has no default operator class for access method \"%s\"",
format_type_be(atttype), "hash"),
errhint("You must specify a hash operator class or define a default hash operator class for the data type.")));
else
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("data type %s has no default operator class for access method \"%s\"",
format_type_be(atttype), "btree"),
errhint("You must specify a btree operator class or define a default btree operator class for the data type.")));
}
}
else
partopclass[attn] = ResolveOpClass(pelem->opclass,
atttype,
am_oid == HASH_AM_OID ? "hash" : "btree",
am_oid);
attn++;
}
}
/*
* PartConstraintImpliedByRelConstraint
* Do scanrel's existing constraints imply the partition constraint?
*
* "Existing constraints" include its check constraints and column-level
* NOT NULL constraints. partConstraint describes the partition constraint,
* in implicit-AND form.
*/
bool
PartConstraintImpliedByRelConstraint(Relation scanrel,
List *partConstraint)
{
List *existConstraint = NIL;
TupleConstr *constr = RelationGetDescr(scanrel)->constr;
int i;
if (constr && constr->has_not_null)
{
int natts = scanrel->rd_att->natts;
for (i = 1; i <= natts; i++)
{
Form_pg_attribute att = TupleDescAttr(scanrel->rd_att, i - 1);
if (att->attnotnull && !att->attisdropped)
{
NullTest *ntest = makeNode(NullTest);
ntest->arg = (Expr *) makeVar(1,
i,
att->atttypid,
att->atttypmod,
att->attcollation,
0);
ntest->nulltesttype = IS_NOT_NULL;
/*
* argisrow=false is correct even for a composite column,
* because attnotnull does not represent a SQL-spec IS NOT
* NULL test in such a case, just IS DISTINCT FROM NULL.
*/
ntest->argisrow = false;
ntest->location = -1;
existConstraint = lappend(existConstraint, ntest);
}
}
}
return ConstraintImpliedByRelConstraint(scanrel, partConstraint, existConstraint);
}
/*
* ConstraintImpliedByRelConstraint
* Do scanrel's existing constraints imply the given constraint?
*
* testConstraint is the constraint to validate. provenConstraint is a
* caller-provided list of conditions which this function may assume
* to be true. Both provenConstraint and testConstraint must be in
* implicit-AND form, must only contain immutable clauses, and must
* contain only Vars with varno = 1.
*/
bool
ConstraintImpliedByRelConstraint(Relation scanrel, List *testConstraint, List *provenConstraint)
{
List *existConstraint = list_copy(provenConstraint);
TupleConstr *constr = RelationGetDescr(scanrel)->constr;
int num_check,
i;
num_check = (constr != NULL) ? constr->num_check : 0;
for (i = 0; i < num_check; i++)
{
Node *cexpr;
/*
* If this constraint hasn't been fully validated yet, we must ignore
* it here.
*/
if (!constr->check[i].ccvalid)
continue;
cexpr = stringToNode(constr->check[i].ccbin);
/*
* Run each expression through const-simplification and
* canonicalization. It is necessary, because we will be comparing it
* to similarly-processed partition constraint expressions, and may
* fail to detect valid matches without this.
*/
cexpr = eval_const_expressions(NULL, cexpr);
cexpr = (Node *) canonicalize_qual((Expr *) cexpr, true);
existConstraint = list_concat(existConstraint,
make_ands_implicit((Expr *) cexpr));
}
/*
* Try to make the proof. Since we are comparing CHECK constraints, we
* need to use weak implication, i.e., we assume existConstraint is
* not-false and try to prove the same for testConstraint.
*
* Note that predicate_implied_by assumes its first argument is known
* immutable. That should always be true for both NOT NULL and partition
* constraints, so we don't test it here.
*/
return predicate_implied_by(testConstraint, existConstraint, true);
}
/*
* QueuePartitionConstraintValidation
*
* Add an entry to wqueue to have the given partition constraint validated by
* Phase 3, for the given relation, and all its children.
*
* We first verify whether the given constraint is implied by pre-existing
* relation constraints; if it is, there's no need to scan the table to
* validate, so don't queue in that case.
*/
static void
QueuePartitionConstraintValidation(List **wqueue, Relation scanrel,
List *partConstraint,
bool validate_default)
{
/*
* Based on the table's existing constraints, determine whether or not we
* may skip scanning the table.
*/
if (PartConstraintImpliedByRelConstraint(scanrel, partConstraint))
{
if (!validate_default)
ereport(DEBUG1,
(errmsg("partition constraint for table \"%s\" is implied by existing constraints",
RelationGetRelationName(scanrel))));
else
ereport(DEBUG1,
(errmsg("updated partition constraint for default partition \"%s\" is implied by existing constraints",
RelationGetRelationName(scanrel))));
return;
}
/*
* Constraints proved insufficient. For plain relations, queue a
* validation item now; for partitioned tables, recurse to process each
* partition.
*/
if (scanrel->rd_rel->relkind == RELKIND_RELATION)
{
AlteredTableInfo *tab;
/* Grab a work queue entry. */
tab = ATGetQueueEntry(wqueue, scanrel);
Assert(tab->partition_constraint == NULL);
tab->partition_constraint = (Expr *) linitial(partConstraint);
tab->validate_default = validate_default;
}
else if (scanrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
{
PartitionDesc partdesc = RelationGetPartitionDesc(scanrel);
int i;
for (i = 0; i < partdesc->nparts; i++)
{
Relation part_rel;
bool found_whole_row;
List *thisPartConstraint;
/*
* This is the minimum lock we need to prevent deadlocks.
*/
part_rel = table_open(partdesc->oids[i], AccessExclusiveLock);
/*
* Adjust the constraint for scanrel so that it matches this
* partition's attribute numbers.
*/
thisPartConstraint =
map_partition_varattnos(partConstraint, 1,
part_rel, scanrel, &found_whole_row);
/* There can never be a whole-row reference here */
if (found_whole_row)
elog(ERROR, "unexpected whole-row reference found in partition constraint");
QueuePartitionConstraintValidation(wqueue, part_rel,
thisPartConstraint,
validate_default);
table_close(part_rel, NoLock); /* keep lock till commit */
}
}
}
/*
* ALTER TABLE <name> ATTACH PARTITION <partition-name> FOR VALUES
*
* Return the address of the newly attached partition.
*/
static ObjectAddress
ATExecAttachPartition(List **wqueue, Relation rel, PartitionCmd *cmd)
{
Relation attachrel,
catalog;
List *attachrel_children;
List *partConstraint;
SysScanDesc scan;
ScanKeyData skey;
AttrNumber attno;
int natts;
TupleDesc tupleDesc;
ObjectAddress address;
const char *trigger_name;
bool found_whole_row;
Oid defaultPartOid;
List *partBoundConstraint;
/*
* We must lock the default partition if one exists, because attaching a
* new partition will change its partition constraint.
*/
defaultPartOid =
get_default_oid_from_partdesc(RelationGetPartitionDesc(rel));
if (OidIsValid(defaultPartOid))
LockRelationOid(defaultPartOid, AccessExclusiveLock);
attachrel = table_openrv(cmd->name, AccessExclusiveLock);
/*
* XXX I think it'd be a good idea to grab locks on all tables referenced
* by FKs at this point also.
*/
/*
* Must be owner of both parent and source table -- parent was checked by
* ATSimplePermissions call in ATPrepCmd
*/
ATSimplePermissions(attachrel, ATT_TABLE | ATT_FOREIGN_TABLE);
/* A partition can only have one parent */
if (attachrel->rd_rel->relispartition)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is already a partition",
RelationGetRelationName(attachrel))));
if (OidIsValid(attachrel->rd_rel->reloftype))
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot attach a typed table as partition")));
/*
* Table being attached should not already be part of inheritance; either
* as a child table...
*/
catalog = table_open(InheritsRelationId, AccessShareLock);
ScanKeyInit(&skey,
Anum_pg_inherits_inhrelid,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(attachrel)));
scan = systable_beginscan(catalog, InheritsRelidSeqnoIndexId, true,
NULL, 1, &skey);
if (HeapTupleIsValid(systable_getnext(scan)))
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot attach inheritance child as partition")));
systable_endscan(scan);
/* ...or as a parent table (except the case when it is partitioned) */
ScanKeyInit(&skey,
Anum_pg_inherits_inhparent,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(attachrel)));
scan = systable_beginscan(catalog, InheritsParentIndexId, true, NULL,
1, &skey);
if (HeapTupleIsValid(systable_getnext(scan)) &&
attachrel->rd_rel->relkind == RELKIND_RELATION)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot attach inheritance parent as partition")));
systable_endscan(scan);
table_close(catalog, AccessShareLock);
/*
* Prevent circularity by seeing if rel is a partition of attachrel. (In
* particular, this disallows making a rel a partition of itself.)
*
* We do that by checking if rel is a member of the list of attachrel's
* partitions provided the latter is partitioned at all. We want to avoid
* having to construct this list again, so we request the strongest lock
* on all partitions. We need the strongest lock, because we may decide
* to scan them if we find out that the table being attached (or its leaf
* partitions) may contain rows that violate the partition constraint. If
* the table has a constraint that would prevent such rows, which by
* definition is present in all the partitions, we need not scan the
* table, nor its partitions. But we cannot risk a deadlock by taking a
* weaker lock now and the stronger one only when needed.
*/
attachrel_children = find_all_inheritors(RelationGetRelid(attachrel),
AccessExclusiveLock, NULL);
if (list_member_oid(attachrel_children, RelationGetRelid(rel)))
ereport(ERROR,
(errcode(ERRCODE_DUPLICATE_TABLE),
errmsg("circular inheritance not allowed"),
errdetail("\"%s\" is already a child of \"%s\".",
RelationGetRelationName(rel),
RelationGetRelationName(attachrel))));
/* If the parent is permanent, so must be all of its partitions. */
if (rel->rd_rel->relpersistence != RELPERSISTENCE_TEMP &&
attachrel->rd_rel->relpersistence == RELPERSISTENCE_TEMP)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot attach a temporary relation as partition of permanent relation \"%s\"",
RelationGetRelationName(rel))));
/* Temp parent cannot have a partition that is itself not a temp */
if (rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
attachrel->rd_rel->relpersistence != RELPERSISTENCE_TEMP)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot attach a permanent relation as partition of temporary relation \"%s\"",
RelationGetRelationName(rel))));
/* If the parent is temp, it must belong to this session */
if (rel->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
!rel->rd_islocaltemp)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot attach as partition of temporary relation of another session")));
/* Ditto for the partition */
if (attachrel->rd_rel->relpersistence == RELPERSISTENCE_TEMP &&
!attachrel->rd_islocaltemp)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot attach temporary relation of another session as partition")));
/* Check if there are any columns in attachrel that aren't in the parent */
tupleDesc = RelationGetDescr(attachrel);
natts = tupleDesc->natts;
for (attno = 1; attno <= natts; attno++)
{
Form_pg_attribute attribute = TupleDescAttr(tupleDesc, attno - 1);
char *attributeName = NameStr(attribute->attname);
/* Ignore dropped */
if (attribute->attisdropped)
continue;
/* Try to find the column in parent (matching on column name) */
if (!SearchSysCacheExists2(ATTNAME,
ObjectIdGetDatum(RelationGetRelid(rel)),
CStringGetDatum(attributeName)))
ereport(ERROR,
(errcode(ERRCODE_DATATYPE_MISMATCH),
errmsg("table \"%s\" contains column \"%s\" not found in parent \"%s\"",
RelationGetRelationName(attachrel), attributeName,
RelationGetRelationName(rel)),
errdetail("The new partition may contain only the columns present in parent.")));
}
/*
* If child_rel has row-level triggers with transition tables, we
* currently don't allow it to become a partition. See also prohibitions
* in ATExecAddInherit() and CreateTrigger().
*/
trigger_name = FindTriggerIncompatibleWithInheritance(attachrel->trigdesc);
if (trigger_name != NULL)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("trigger \"%s\" prevents table \"%s\" from becoming a partition",
trigger_name, RelationGetRelationName(attachrel)),
errdetail("ROW triggers with transition tables are not supported on partitions")));
/*
* Check that the new partition's bound is valid and does not overlap any
* of existing partitions of the parent - note that it does not return on
* error.
*/
check_new_partition_bound(RelationGetRelationName(attachrel), rel,
cmd->bound);
/* OK to create inheritance. Rest of the checks performed there */
CreateInheritance(attachrel, rel);
/* Update the pg_class entry. */
StorePartitionBound(attachrel, rel, cmd->bound);
/* Ensure there exists a correct set of indexes in the partition. */
AttachPartitionEnsureIndexes(rel, attachrel);
/* and triggers */
CloneRowTriggersToPartition(rel, attachrel);
/*
* Clone foreign key constraints. Callee is responsible for setting up
* for phase 3 constraint verification.
*/
CloneForeignKeyConstraints(wqueue, rel, attachrel);
/*
* Generate partition constraint from the partition bound specification.
* If the parent itself is a partition, make sure to include its
* constraint as well.
*/
partBoundConstraint = get_qual_from_partbound(attachrel, rel, cmd->bound);
partConstraint = list_concat(partBoundConstraint,
RelationGetPartitionQual(rel));
/* Skip validation if there are no constraints to validate. */
if (partConstraint)
{
/*
* Run the partition quals through const-simplification similar to
* check constraints. We skip canonicalize_qual, though, because
* partition quals should be in canonical form already.
*/
partConstraint =
(List *) eval_const_expressions(NULL,
(Node *) partConstraint);
/* XXX this sure looks wrong */
partConstraint = list_make1(make_ands_explicit(partConstraint));
/*
* Adjust the generated constraint to match this partition's attribute
* numbers.
*/
partConstraint = map_partition_varattnos(partConstraint, 1, attachrel,
rel, &found_whole_row);
/* There can never be a whole-row reference here */
if (found_whole_row)
elog(ERROR,
"unexpected whole-row reference found in partition key");
/* Validate partition constraints against the table being attached. */
QueuePartitionConstraintValidation(wqueue, attachrel, partConstraint,
false);
}
/*
* If we're attaching a partition other than the default partition and a
* default one exists, then that partition's partition constraint changes,
* so add an entry to the work queue to validate it, too. (We must not do
* this when the partition being attached is the default one; we already
* did it above!)
*/
if (OidIsValid(defaultPartOid))
{
Relation defaultrel;
List *defPartConstraint;
Assert(!cmd->bound->is_default);
/* we already hold a lock on the default partition */
defaultrel = table_open(defaultPartOid, NoLock);
defPartConstraint =
get_proposed_default_constraint(partBoundConstraint);
/*
* Map the Vars in the constraint expression from rel's attnos to
* defaultrel's.
*/
defPartConstraint =
map_partition_varattnos(defPartConstraint,
1, defaultrel, rel, NULL);
QueuePartitionConstraintValidation(wqueue, defaultrel,
defPartConstraint, true);
/* keep our lock until commit. */
table_close(defaultrel, NoLock);
}
ObjectAddressSet(address, RelationRelationId, RelationGetRelid(attachrel));
/* keep our lock until commit */
table_close(attachrel, NoLock);
return address;
}
/*
* AttachPartitionEnsureIndexes
* subroutine for ATExecAttachPartition to create/match indexes
*
* Enforce the indexing rule for partitioned tables during ALTER TABLE / ATTACH
* PARTITION: every partition must have an index attached to each index on the
* partitioned table.
*/
static void
AttachPartitionEnsureIndexes(Relation rel, Relation attachrel)
{
List *idxes;
List *attachRelIdxs;
Relation *attachrelIdxRels;
IndexInfo **attachInfos;
int i;
ListCell *cell;
MemoryContext cxt;
MemoryContext oldcxt;
cxt = AllocSetContextCreate(CurrentMemoryContext,
"AttachPartitionEnsureIndexes",
ALLOCSET_DEFAULT_SIZES);
oldcxt = MemoryContextSwitchTo(cxt);
idxes = RelationGetIndexList(rel);
attachRelIdxs = RelationGetIndexList(attachrel);
attachrelIdxRels = palloc(sizeof(Relation) * list_length(attachRelIdxs));
attachInfos = palloc(sizeof(IndexInfo *) * list_length(attachRelIdxs));
/* Build arrays of all existing indexes and their IndexInfos */
i = 0;
foreach(cell, attachRelIdxs)
{
Oid cldIdxId = lfirst_oid(cell);
attachrelIdxRels[i] = index_open(cldIdxId, AccessShareLock);
attachInfos[i] = BuildIndexInfo(attachrelIdxRels[i]);
i++;
}
/*
* If we're attaching a foreign table, we must fail if any of the indexes
* is a constraint index; otherwise, there's nothing to do here. Do this
* before starting work, to avoid wasting the effort of building a few
* non-unique indexes before coming across a unique one.
*/
if (attachrel->rd_rel->relkind == RELKIND_FOREIGN_TABLE)
{
foreach(cell, idxes)
{
Oid idx = lfirst_oid(cell);
Relation idxRel = index_open(idx, AccessShareLock);
if (idxRel->rd_index->indisunique ||
idxRel->rd_index->indisprimary)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot attach foreign table \"%s\" as partition of partitioned table \"%s\"",
RelationGetRelationName(attachrel),
RelationGetRelationName(rel)),
errdetail("Table \"%s\" contains unique indexes.",
RelationGetRelationName(rel))));
index_close(idxRel, AccessShareLock);
}
goto out;
}
/*
* For each index on the partitioned table, find a matching one in the
* partition-to-be; if one is not found, create one.
*/
foreach(cell, idxes)
{
Oid idx = lfirst_oid(cell);
Relation idxRel = index_open(idx, AccessShareLock);
IndexInfo *info;
AttrNumber *attmap;
bool found = false;
Oid constraintOid;
/*
* Ignore indexes in the partitioned table other than partitioned
* indexes.
*/
if (idxRel->rd_rel->relkind != RELKIND_PARTITIONED_INDEX)
{
index_close(idxRel, AccessShareLock);
continue;
}
/* construct an indexinfo to compare existing indexes against */
info = BuildIndexInfo(idxRel);
attmap = convert_tuples_by_name_map(RelationGetDescr(attachrel),
RelationGetDescr(rel));
constraintOid = get_relation_idx_constraint_oid(RelationGetRelid(rel), idx);
/*
* Scan the list of existing indexes in the partition-to-be, and mark
* the first matching, unattached one we find, if any, as partition of
* the parent index. If we find one, we're done.
*/
for (i = 0; i < list_length(attachRelIdxs); i++)
{
Oid cldIdxId = RelationGetRelid(attachrelIdxRels[i]);
Oid cldConstrOid = InvalidOid;
/* does this index have a parent? if so, can't use it */
if (attachrelIdxRels[i]->rd_rel->relispartition)
continue;
if (CompareIndexInfo(attachInfos[i], info,
attachrelIdxRels[i]->rd_indcollation,
idxRel->rd_indcollation,
attachrelIdxRels[i]->rd_opfamily,
idxRel->rd_opfamily,
attmap,
RelationGetDescr(rel)->natts))
{
/*
* If this index is being created in the parent because of a
* constraint, then the child needs to have a constraint also,
* so look for one. If there is no such constraint, this
* index is no good, so keep looking.
*/
if (OidIsValid(constraintOid))
{
cldConstrOid =
get_relation_idx_constraint_oid(RelationGetRelid(attachrel),
cldIdxId);
/* no dice */
if (!OidIsValid(cldConstrOid))
continue;
}
/* bingo. */
IndexSetParentIndex(attachrelIdxRels[i], idx);
if (OidIsValid(constraintOid))
ConstraintSetParentConstraint(cldConstrOid, constraintOid,
RelationGetRelid(attachrel));
found = true;
CommandCounterIncrement();
break;
}
}
/*
* If no suitable index was found in the partition-to-be, create one
* now.
*/
if (!found)
{
IndexStmt *stmt;
Oid constraintOid;
stmt = generateClonedIndexStmt(NULL,
idxRel, attmap,
RelationGetDescr(rel)->natts,
&constraintOid);
DefineIndex(RelationGetRelid(attachrel), stmt, InvalidOid,
RelationGetRelid(idxRel),
constraintOid,
true, false, false, false, false);
}
index_close(idxRel, AccessShareLock);
}
out:
/* Clean up. */
for (i = 0; i < list_length(attachRelIdxs); i++)
index_close(attachrelIdxRels[i], AccessShareLock);
MemoryContextSwitchTo(oldcxt);
MemoryContextDelete(cxt);
}
/*
* CloneRowTriggersToPartition
* subroutine for ATExecAttachPartition/DefineRelation to create row
* triggers on partitions
*/
static void
CloneRowTriggersToPartition(Relation parent, Relation partition)
{
Relation pg_trigger;
ScanKeyData key;
SysScanDesc scan;
HeapTuple tuple;
MemoryContext perTupCxt;
ScanKeyInit(&key, Anum_pg_trigger_tgrelid, BTEqualStrategyNumber,
F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(parent)));
pg_trigger = table_open(TriggerRelationId, RowExclusiveLock);
scan = systable_beginscan(pg_trigger, TriggerRelidNameIndexId,
true, NULL, 1, &key);
perTupCxt = AllocSetContextCreate(CurrentMemoryContext,
"clone trig", ALLOCSET_SMALL_SIZES);
while (HeapTupleIsValid(tuple = systable_getnext(scan)))
{
Form_pg_trigger trigForm = (Form_pg_trigger) GETSTRUCT(tuple);
CreateTrigStmt *trigStmt;
Node *qual = NULL;
Datum value;
bool isnull;
List *cols = NIL;
List *trigargs = NIL;
MemoryContext oldcxt;
/*
* Ignore statement-level triggers; those are not cloned.
*/
if (!TRIGGER_FOR_ROW(trigForm->tgtype))
continue;
/* We don't clone internal triggers, either */
if (trigForm->tgisinternal)
continue;
/*
* Complain if we find an unexpected trigger type.
*/
if (!TRIGGER_FOR_AFTER(trigForm->tgtype))
elog(ERROR, "unexpected trigger \"%s\" found",
NameStr(trigForm->tgname));
/* Use short-lived context for CREATE TRIGGER */
oldcxt = MemoryContextSwitchTo(perTupCxt);
/*
* If there is a WHEN clause, generate a 'cooked' version of it that's
* appropriate for the partition.
*/
value = heap_getattr(tuple, Anum_pg_trigger_tgqual,
RelationGetDescr(pg_trigger), &isnull);
if (!isnull)
{
bool found_whole_row;
qual = stringToNode(TextDatumGetCString(value));
qual = (Node *) map_partition_varattnos((List *) qual, PRS2_OLD_VARNO,
partition, parent,
&found_whole_row);
if (found_whole_row)
elog(ERROR, "unexpected whole-row reference found in trigger WHEN clause");
qual = (Node *) map_partition_varattnos((List *) qual, PRS2_NEW_VARNO,
partition, parent,
&found_whole_row);
if (found_whole_row)
elog(ERROR, "unexpected whole-row reference found in trigger WHEN clause");
}
/*
* If there is a column list, transform it to a list of column names.
* Note we don't need to map this list in any way ...
*/
if (trigForm->tgattr.dim1 > 0)
{
int i;
for (i = 0; i < trigForm->tgattr.dim1; i++)
{
Form_pg_attribute col;
col = TupleDescAttr(parent->rd_att,
trigForm->tgattr.values[i] - 1);
cols = lappend(cols,
makeString(pstrdup(NameStr(col->attname))));
}
}
/* Reconstruct trigger arguments list. */
if (trigForm->tgnargs > 0)
{
char *p;
value = heap_getattr(tuple, Anum_pg_trigger_tgargs,
RelationGetDescr(pg_trigger), &isnull);
if (isnull)
elog(ERROR, "tgargs is null for trigger \"%s\" in partition \"%s\"",
NameStr(trigForm->tgname), RelationGetRelationName(partition));
p = (char *) VARDATA_ANY(DatumGetByteaPP(value));
for (int i = 0; i < trigForm->tgnargs; i++)
{
trigargs = lappend(trigargs, makeString(pstrdup(p)));
p += strlen(p) + 1;
}
}
trigStmt = makeNode(CreateTrigStmt);
trigStmt->trigname = NameStr(trigForm->tgname);
trigStmt->relation = NULL;
trigStmt->funcname = NULL; /* passed separately */
trigStmt->args = trigargs;
trigStmt->row = true;
trigStmt->timing = trigForm->tgtype & TRIGGER_TYPE_TIMING_MASK;
trigStmt->events = trigForm->tgtype & TRIGGER_TYPE_EVENT_MASK;
trigStmt->columns = cols;
trigStmt->whenClause = NULL; /* passed separately */
trigStmt->isconstraint = OidIsValid(trigForm->tgconstraint);
trigStmt->transitionRels = NIL; /* not supported at present */
trigStmt->deferrable = trigForm->tgdeferrable;
trigStmt->initdeferred = trigForm->tginitdeferred;
trigStmt->constrrel = NULL; /* passed separately */
CreateTrigger(trigStmt, NULL, RelationGetRelid(partition),
trigForm->tgconstrrelid, InvalidOid, InvalidOid,
trigForm->tgfoid, trigForm->oid, qual,
false, true);
MemoryContextSwitchTo(oldcxt);
MemoryContextReset(perTupCxt);
}
MemoryContextDelete(perTupCxt);
systable_endscan(scan);
table_close(pg_trigger, RowExclusiveLock);
}
/*
* ALTER TABLE DETACH PARTITION
*
* Return the address of the relation that is no longer a partition of rel.
*/
static ObjectAddress
ATExecDetachPartition(Relation rel, RangeVar *name)
{
Relation partRel,
classRel;
HeapTuple tuple,
newtuple;
Datum new_val[Natts_pg_class];
bool new_null[Natts_pg_class],
new_repl[Natts_pg_class];
ObjectAddress address;
Oid defaultPartOid;
List *indexes;
List *fks;
ListCell *cell;
/*
* We must lock the default partition, because detaching this partition
* will change its partition constraint.
*/
defaultPartOid =
get_default_oid_from_partdesc(RelationGetPartitionDesc(rel));
if (OidIsValid(defaultPartOid))
LockRelationOid(defaultPartOid, AccessExclusiveLock);
partRel = table_openrv(name, ShareUpdateExclusiveLock);
/* Ensure that foreign keys still hold after this detach */
ATDetachCheckNoForeignKeyRefs(partRel);
/* All inheritance related checks are performed within the function */
RemoveInheritance(partRel, rel);
/* Update pg_class tuple */
classRel = table_open(RelationRelationId, RowExclusiveLock);
tuple = SearchSysCacheCopy1(RELOID,
ObjectIdGetDatum(RelationGetRelid(partRel)));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for relation %u",
RelationGetRelid(partRel));
Assert(((Form_pg_class) GETSTRUCT(tuple))->relispartition);
/* Clear relpartbound and reset relispartition */
memset(new_val, 0, sizeof(new_val));
memset(new_null, false, sizeof(new_null));
memset(new_repl, false, sizeof(new_repl));
new_val[Anum_pg_class_relpartbound - 1] = (Datum) 0;
new_null[Anum_pg_class_relpartbound - 1] = true;
new_repl[Anum_pg_class_relpartbound - 1] = true;
newtuple = heap_modify_tuple(tuple, RelationGetDescr(classRel),
new_val, new_null, new_repl);
((Form_pg_class) GETSTRUCT(newtuple))->relispartition = false;
CatalogTupleUpdate(classRel, &newtuple->t_self, newtuple);
heap_freetuple(newtuple);
if (OidIsValid(defaultPartOid))
{
/*
* If the relation being detached is the default partition itself,
* remove it from the parent's pg_partitioned_table entry.
*
* If not, we must invalidate default partition's relcache entry, as
* in StorePartitionBound: its partition constraint depends on every
* other partition's partition constraint.
*/
if (RelationGetRelid(partRel) == defaultPartOid)
update_default_partition_oid(RelationGetRelid(rel), InvalidOid);
else
CacheInvalidateRelcacheByRelid(defaultPartOid);
}
/* detach indexes too */
indexes = RelationGetIndexList(partRel);
foreach(cell, indexes)
{
Oid idxid = lfirst_oid(cell);
Relation idx;
Oid constrOid;
if (!has_superclass(idxid))
continue;
Assert((IndexGetRelation(get_partition_parent(idxid), false) ==
RelationGetRelid(rel)));
idx = index_open(idxid, AccessExclusiveLock);
IndexSetParentIndex(idx, InvalidOid);
/* If there's a constraint associated with the index, detach it too */
constrOid = get_relation_idx_constraint_oid(RelationGetRelid(partRel),
idxid);
if (OidIsValid(constrOid))
ConstraintSetParentConstraint(constrOid, InvalidOid, InvalidOid);
index_close(idx, NoLock);
}
table_close(classRel, RowExclusiveLock);
/*
* Detach any foreign keys that are inherited. This includes creating
* additional action triggers.
*/
fks = copyObject(RelationGetFKeyList(partRel));
foreach(cell, fks)
{
ForeignKeyCacheInfo *fk = lfirst(cell);
HeapTuple contup;
Form_pg_constraint conform;
Constraint *fkconstraint;
contup = SearchSysCache1(CONSTROID, ObjectIdGetDatum(fk->conoid));
if (!HeapTupleIsValid(contup))
elog(ERROR, "cache lookup failed for constraint %u", fk->conoid);
conform = (Form_pg_constraint) GETSTRUCT(contup);
/* consider only the inherited foreign keys */
if (conform->contype != CONSTRAINT_FOREIGN ||
!OidIsValid(conform->conparentid))
{
ReleaseSysCache(contup);
continue;
}
/* unset conparentid and adjust conislocal, coninhcount, etc. */
ConstraintSetParentConstraint(fk->conoid, InvalidOid, InvalidOid);
/*
* Make the action triggers on the referenced relation. When this was
* a partition the action triggers pointed to the parent rel (they
* still do), but now we need separate ones of our own.
*/
fkconstraint = makeNode(Constraint);
fkconstraint->conname = pstrdup(NameStr(conform->conname));
fkconstraint->fk_upd_action = conform->confupdtype;
fkconstraint->fk_del_action = conform->confdeltype;
fkconstraint->deferrable = conform->condeferrable;
fkconstraint->initdeferred = conform->condeferred;
createForeignKeyActionTriggers(partRel, conform->confrelid,
fkconstraint, fk->conoid,
conform->conindid);
ReleaseSysCache(contup);
}
list_free_deep(fks);
/*
* Any sub-constrains that are in the referenced-side of a larger
* constraint have to be removed. This partition is no longer part of the
* key space of the constraint.
*/
foreach(cell, GetParentedForeignKeyRefs(partRel))
{
Oid constrOid = lfirst_oid(cell);
ObjectAddress constraint;
ConstraintSetParentConstraint(constrOid, InvalidOid, InvalidOid);
deleteDependencyRecordsForClass(ConstraintRelationId,
constrOid,
ConstraintRelationId,
DEPENDENCY_INTERNAL);
CommandCounterIncrement();
ObjectAddressSet(constraint, ConstraintRelationId, constrOid);
performDeletion(&constraint, DROP_RESTRICT, 0);
}
CommandCounterIncrement();
/*
* Invalidate the parent's relcache so that the partition is no longer
* included in its partition descriptor.
*/
CacheInvalidateRelcache(rel);
ObjectAddressSet(address, RelationRelationId, RelationGetRelid(partRel));
/* keep our lock until commit */
table_close(partRel, NoLock);
return address;
}
/*
* Before acquiring lock on an index, acquire the same lock on the owning
* table.
*/
struct AttachIndexCallbackState
{
Oid partitionOid;
Oid parentTblOid;
bool lockedParentTbl;
};
static void
RangeVarCallbackForAttachIndex(const RangeVar *rv, Oid relOid, Oid oldRelOid,
void *arg)
{
struct AttachIndexCallbackState *state;
Form_pg_class classform;
HeapTuple tuple;
state = (struct AttachIndexCallbackState *) arg;
if (!state->lockedParentTbl)
{
LockRelationOid(state->parentTblOid, AccessShareLock);
state->lockedParentTbl = true;
}
/*
* If we previously locked some other heap, and the name we're looking up
* no longer refers to an index on that relation, release the now-useless
* lock. XXX maybe we should do *after* we verify whether the index does
* not actually belong to the same relation ...
*/
if (relOid != oldRelOid && OidIsValid(state->partitionOid))
{
UnlockRelationOid(state->partitionOid, AccessShareLock);
state->partitionOid = InvalidOid;
}
/* Didn't find a relation, so no need for locking or permission checks. */
if (!OidIsValid(relOid))
return;
tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relOid));
if (!HeapTupleIsValid(tuple))
return; /* concurrently dropped, so nothing to do */
classform = (Form_pg_class) GETSTRUCT(tuple);
if (classform->relkind != RELKIND_PARTITIONED_INDEX &&
classform->relkind != RELKIND_INDEX)
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("\"%s\" is not an index", rv->relname)));
ReleaseSysCache(tuple);
/*
* Since we need only examine the heap's tupledesc, an access share lock
* on it (preventing any DDL) is sufficient.
*/
state->partitionOid = IndexGetRelation(relOid, false);
LockRelationOid(state->partitionOid, AccessShareLock);
}
/*
* ALTER INDEX i1 ATTACH PARTITION i2
*/
static ObjectAddress
ATExecAttachPartitionIdx(List **wqueue, Relation parentIdx, RangeVar *name)
{
Relation partIdx;
Relation partTbl;
Relation parentTbl;
ObjectAddress address;
Oid partIdxId;
Oid currParent;
struct AttachIndexCallbackState state;
/*
* We need to obtain lock on the index 'name' to modify it, but we also
* need to read its owning table's tuple descriptor -- so we need to lock
* both. To avoid deadlocks, obtain lock on the table before doing so on
* the index. Furthermore, we need to examine the parent table of the
* partition, so lock that one too.
*/
state.partitionOid = InvalidOid;
state.parentTblOid = parentIdx->rd_index->indrelid;
state.lockedParentTbl = false;
partIdxId =
RangeVarGetRelidExtended(name, AccessExclusiveLock, 0,
RangeVarCallbackForAttachIndex,
(void *) &state);
/* Not there? */
if (!OidIsValid(partIdxId))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("index \"%s\" does not exist", name->relname)));
/* no deadlock risk: RangeVarGetRelidExtended already acquired the lock */
partIdx = relation_open(partIdxId, AccessExclusiveLock);
/* we already hold locks on both tables, so this is safe: */
parentTbl = relation_open(parentIdx->rd_index->indrelid, AccessShareLock);
partTbl = relation_open(partIdx->rd_index->indrelid, NoLock);
ObjectAddressSet(address, RelationRelationId, RelationGetRelid(partIdx));
/* Silently do nothing if already in the right state */
currParent = partIdx->rd_rel->relispartition ?
get_partition_parent(partIdxId) : InvalidOid;
if (currParent != RelationGetRelid(parentIdx))
{
IndexInfo *childInfo;
IndexInfo *parentInfo;
AttrNumber *attmap;
bool found;
int i;
PartitionDesc partDesc;
Oid constraintOid,
cldConstrId = InvalidOid;
/*
* If this partition already has an index attached, refuse the
* operation.
*/
refuseDupeIndexAttach(parentIdx, partIdx, partTbl);
if (OidIsValid(currParent))
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("cannot attach index \"%s\" as a partition of index \"%s\"",
RelationGetRelationName(partIdx),
RelationGetRelationName(parentIdx)),
errdetail("Index \"%s\" is already attached to another index.",
RelationGetRelationName(partIdx))));
/* Make sure it indexes a partition of the other index's table */
partDesc = RelationGetPartitionDesc(parentTbl);
found = false;
for (i = 0; i < partDesc->nparts; i++)
{
if (partDesc->oids[i] == state.partitionOid)
{
found = true;
break;
}
}
if (!found)
ereport(ERROR,
(errmsg("cannot attach index \"%s\" as a partition of index \"%s\"",
RelationGetRelationName(partIdx),
RelationGetRelationName(parentIdx)),
errdetail("Index \"%s\" is not an index on any partition of table \"%s\".",
RelationGetRelationName(partIdx),
RelationGetRelationName(parentTbl))));
/* Ensure the indexes are compatible */
childInfo = BuildIndexInfo(partIdx);
parentInfo = BuildIndexInfo(parentIdx);
attmap = convert_tuples_by_name_map(RelationGetDescr(partTbl),
RelationGetDescr(parentTbl));
if (!CompareIndexInfo(childInfo, parentInfo,
partIdx->rd_indcollation,
parentIdx->rd_indcollation,
partIdx->rd_opfamily,
parentIdx->rd_opfamily,
attmap,
RelationGetDescr(parentTbl)->natts))
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("cannot attach index \"%s\" as a partition of index \"%s\"",
RelationGetRelationName(partIdx),
RelationGetRelationName(parentIdx)),
errdetail("The index definitions do not match.")));
/*
* If there is a constraint in the parent, make sure there is one in
* the child too.
*/
constraintOid = get_relation_idx_constraint_oid(RelationGetRelid(parentTbl),
RelationGetRelid(parentIdx));
if (OidIsValid(constraintOid))
{
cldConstrId = get_relation_idx_constraint_oid(RelationGetRelid(partTbl),
partIdxId);
if (!OidIsValid(cldConstrId))
ereport(ERROR,
(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
errmsg("cannot attach index \"%s\" as a partition of index \"%s\"",
RelationGetRelationName(partIdx),
RelationGetRelationName(parentIdx)),
errdetail("The index \"%s\" belongs to a constraint in table \"%s\" but no constraint exists for index \"%s\".",
RelationGetRelationName(parentIdx),
RelationGetRelationName(parentTbl),
RelationGetRelationName(partIdx))));
}
/* All good -- do it */
IndexSetParentIndex(partIdx, RelationGetRelid(parentIdx));
if (OidIsValid(constraintOid))
ConstraintSetParentConstraint(cldConstrId, constraintOid,
RelationGetRelid(partTbl));
pfree(attmap);
validatePartitionedIndex(parentIdx, parentTbl);
}
relation_close(parentTbl, AccessShareLock);
/* keep these locks till commit */
relation_close(partTbl, NoLock);
relation_close(partIdx, NoLock);
return address;
}
/*
* Verify whether the given partition already contains an index attached
* to the given partitioned index. If so, raise an error.
*/
static void
refuseDupeIndexAttach(Relation parentIdx, Relation partIdx, Relation partitionTbl)
{
Oid existingIdx;
existingIdx = index_get_partition(partitionTbl,
RelationGetRelid(parentIdx));
if (OidIsValid(existingIdx))
ereport(ERROR,
(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
errmsg("cannot attach index \"%s\" as a partition of index \"%s\"",
RelationGetRelationName(partIdx),
RelationGetRelationName(parentIdx)),
errdetail("Another index is already attached for partition \"%s\".",
RelationGetRelationName(partitionTbl))));
}
/*
* Verify whether the set of attached partition indexes to a parent index on
* a partitioned table is complete. If it is, mark the parent index valid.
*
* This should be called each time a partition index is attached.
*/
static void
validatePartitionedIndex(Relation partedIdx, Relation partedTbl)
{
Relation inheritsRel;
SysScanDesc scan;
ScanKeyData key;
int tuples = 0;
HeapTuple inhTup;
bool updated = false;
Assert(partedIdx->rd_rel->relkind == RELKIND_PARTITIONED_INDEX);
/*
* Scan pg_inherits for this parent index. Count each valid index we find
* (verifying the pg_index entry for each), and if we reach the total
* amount we expect, we can mark this parent index as valid.
*/
inheritsRel = table_open(InheritsRelationId, AccessShareLock);
ScanKeyInit(&key, Anum_pg_inherits_inhparent,
BTEqualStrategyNumber, F_OIDEQ,
ObjectIdGetDatum(RelationGetRelid(partedIdx)));
scan = systable_beginscan(inheritsRel, InheritsParentIndexId, true,
NULL, 1, &key);
while ((inhTup = systable_getnext(scan)) != NULL)
{
Form_pg_inherits inhForm = (Form_pg_inherits) GETSTRUCT(inhTup);
HeapTuple indTup;
Form_pg_index indexForm;
indTup = SearchSysCache1(INDEXRELID,
ObjectIdGetDatum(inhForm->inhrelid));
if (!HeapTupleIsValid(indTup))
elog(ERROR, "cache lookup failed for index %u", inhForm->inhrelid);
indexForm = (Form_pg_index) GETSTRUCT(indTup);
if (indexForm->indisvalid)
tuples += 1;
ReleaseSysCache(indTup);
}
/* Done with pg_inherits */
systable_endscan(scan);
table_close(inheritsRel, AccessShareLock);
/*
* If we found as many inherited indexes as the partitioned table has
* partitions, we're good; update pg_index to set indisvalid.
*/
if (tuples == RelationGetPartitionDesc(partedTbl)->nparts)
{
Relation idxRel;
HeapTuple newtup;
idxRel = table_open(IndexRelationId, RowExclusiveLock);
newtup = heap_copytuple(partedIdx->rd_indextuple);
((Form_pg_index) GETSTRUCT(newtup))->indisvalid = true;
updated = true;
CatalogTupleUpdate(idxRel, &partedIdx->rd_indextuple->t_self, newtup);
table_close(idxRel, RowExclusiveLock);
}
/*
* If this index is in turn a partition of a larger index, validating it
* might cause the parent to become valid also. Try that.
*/
if (updated && partedIdx->rd_rel->relispartition)
{
Oid parentIdxId,
parentTblId;
Relation parentIdx,
parentTbl;
/* make sure we see the validation we just did */
CommandCounterIncrement();
parentIdxId = get_partition_parent(RelationGetRelid(partedIdx));
parentTblId = get_partition_parent(RelationGetRelid(partedTbl));
parentIdx = relation_open(parentIdxId, AccessExclusiveLock);
parentTbl = relation_open(parentTblId, AccessExclusiveLock);
Assert(!parentIdx->rd_index->indisvalid);
validatePartitionedIndex(parentIdx, parentTbl);
relation_close(parentIdx, AccessExclusiveLock);
relation_close(parentTbl, AccessExclusiveLock);
}
}
/*
* Return an OID list of constraints that reference the given relation
* that are marked as having a parent constraints.
*/
static List *
GetParentedForeignKeyRefs(Relation partition)
{
Relation pg_constraint;
HeapTuple tuple;
SysScanDesc scan;
ScanKeyData key[2];
List *constraints = NIL;
/*
* If no indexes, or no columns are referenceable by FKs, we can avoid the
* scan.
*/
if (RelationGetIndexList(partition) == NIL ||
bms_is_empty(RelationGetIndexAttrBitmap(partition,
INDEX_ATTR_BITMAP_KEY)))
return NIL;
/* Search for constraints referencing this table */
pg_constraint = table_open(ConstraintRelationId, AccessShareLock);
ScanKeyInit(&key[0],
Anum_pg_constraint_confrelid, BTEqualStrategyNumber,
F_OIDEQ, ObjectIdGetDatum(RelationGetRelid(partition)));
ScanKeyInit(&key[1],
Anum_pg_constraint_contype, BTEqualStrategyNumber,
F_CHAREQ, CharGetDatum(CONSTRAINT_FOREIGN));
/* XXX This is a seqscan, as we don't have a usable index */
scan = systable_beginscan(pg_constraint, InvalidOid, true, NULL, 2, key);
while ((tuple = systable_getnext(scan)) != NULL)
{
Form_pg_constraint constrForm = (Form_pg_constraint) GETSTRUCT(tuple);
/*
* We only need to process constraints that are part of larger ones.
*/
if (!OidIsValid(constrForm->conparentid))
continue;
constraints = lappend_oid(constraints, constrForm->oid);
}
systable_endscan(scan);
table_close(pg_constraint, AccessShareLock);
return constraints;
}
/*
* During DETACH PARTITION, verify that any foreign keys pointing to the
* partitioned table would not become invalid. An error is raised if any
* referenced values exist.
*/
static void
ATDetachCheckNoForeignKeyRefs(Relation partition)
{
List *constraints;
ListCell *cell;
constraints = GetParentedForeignKeyRefs(partition);
foreach(cell, constraints)
{
Oid constrOid = lfirst_oid(cell);
HeapTuple tuple;
Form_pg_constraint constrForm;
Relation rel;
Trigger trig;
tuple = SearchSysCache1(CONSTROID, ObjectIdGetDatum(constrOid));
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for constraint %u", constrOid);
constrForm = (Form_pg_constraint) GETSTRUCT(tuple);
Assert(OidIsValid(constrForm->conparentid));
Assert(constrForm->confrelid == RelationGetRelid(partition));
/* prevent data changes into the referencing table until commit */
rel = table_open(constrForm->conrelid, ShareLock);
MemSet(&trig, 0, sizeof(trig));
trig.tgoid = InvalidOid;
trig.tgname = NameStr(constrForm->conname);
trig.tgenabled = TRIGGER_FIRES_ON_ORIGIN;
trig.tgisinternal = true;
trig.tgconstrrelid = RelationGetRelid(partition);
trig.tgconstrindid = constrForm->conindid;
trig.tgconstraint = constrForm->oid;
trig.tgdeferrable = false;
trig.tginitdeferred = false;
/* we needn't fill in remaining fields */
RI_PartitionRemove_Check(&trig, rel, partition);
ReleaseSysCache(tuple);
table_close(rel, NoLock);
}
}
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