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Implementation of UNIONs.

This commit is contained in:
Bruce Momjian 1997-12-24 06:06:58 +00:00
parent 18adbd9aed
commit 6231e161c9
7 changed files with 95 additions and 91 deletions
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15
src/backend/nodes/copyfuncs.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.25 1997/12/23 21:49:03 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.26 1997/12/24 06:05:52 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -1566,7 +1566,18 @@ _copyQuery(Query *from)
}
else
newnode->qry_aggs = NULL;
if (from->unionClause)
{
List *ulist, *temp_list = NIL;
foreach(ulist, from->unionClause)
temp_list = lappend(temp_list,copyObject(lfirst(ulist)));
newnode->unionClause = temp_list;
}
else
newnode->unionClause = NULL;
return newnode;
}

20
src/backend/optimizer/plan/planner.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.15 1997/12/22 05:42:08 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.16 1997/12/24 06:06:01 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -81,11 +81,19 @@ planner(Query *parse)
int rt_index;
/*
* plan inheritance
*/
rt_index = first_matching_rt_entry(rangetable, INHERITS_FLAG);
if (rt_index != -1)
if (parse->unionClause)
{
result_plan = (Plan *) plan_union_queries(0, /* none */
parse,
UNION_FLAG);
/* XXX do we need to do this? bjm 12/19/97 */
tlist = preprocess_targetlist(tlist,
parse->commandType,
parse->resultRelation,
parse->rtable);
}
else if ((rt_index =
first_matching_rt_entry(rangetable, INHERITS_FLAG)) != -1)
{
result_plan = (Plan *) plan_union_queries((Index) rt_index,
parse,

71
src/backend/optimizer/prep/prepunion.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.12 1997/12/21 05:18:28 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/prep/prepunion.c,v 1.13 1997/12/24 06:06:07 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -149,20 +149,51 @@ plan_union_queries(Index rt_index,
find_all_inheritors(lconsi(rt_entry->relid,
NIL),
NIL);
/*
* Remove the flag for this relation, since we're about to handle it
* (do it before recursing!). XXX destructive parse tree change
*/
switch (flag)
{
case INHERITS_FLAG:
rt_fetch(rt_index, rangetable)->inh = false;
break;
default:
break;
}
/*
* XXX - can't find any reason to sort union-relids as paul did, so
* we're leaving it out for now (maybe forever) - jeff & lp
*
* [maybe so. btw, jeff & lp did the lisp conversion, according to Paul.
* -- ay 10/94.]
*/
union_plans = plan_union_query(union_relids, rt_index, rt_entry,
parse, flag, &union_rt_entries);
return (make_append(union_plans,
rt_index,
union_rt_entries,
((Plan *) lfirst(union_plans))->targetlist));
break;
#if 0
case UNION_FLAG:
{
Index rt_index = 0;
List *ulist, *hold_union, *union_plans;
union_plans = handleunion(root, rangetable, tlist, qual);
hold_union = parse->unionClause;
parse->unionClause = NULL; /* prevent looping */
union_plans = lcons(planner(parse), NIL);
foreach(ulist, hold_union)
union_plans = lappend(union_plans, planner(lfirst(ulist)));
return (make_append(union_plans,
rt_index, rangetable,
((Plan *) lfirst(union_plans))->targetlist));
}
break;
#endif
case VERSION_FLAG:
union_relids = VersionGetParents(rt_entry->relid);
@ -172,34 +203,6 @@ plan_union_queries(Index rt_index,
/* do nothing */
break;
}
/*
* Remove the flag for this relation, since we're about to handle it
* (do it before recursing!). XXX destructive parse tree change
*/
switch (flag)
{
case INHERITS_FLAG:
rt_fetch(rt_index, rangetable)->inh = false;
break;
default:
break;
}
/*
* XXX - can't find any reason to sort union-relids as paul did, so
* we're leaving it out for now (maybe forever) - jeff & lp
*
* [maybe so. btw, jeff & lp did the lisp conversion, according to Paul.
* -- ay 10/94.]
*/
union_plans = plan_union_query(union_relids, rt_index, rt_entry,
parse, flag, &union_rt_entries);
return (make_append(union_plans,
rt_index,
union_rt_entries,
((Plan *) lfirst(union_plans))->targetlist));
}

30
src/backend/parser/analyze.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.55 1997/12/23 19:39:42 thomas Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.56 1997/12/24 06:06:18 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -821,18 +821,7 @@ transformSelectStmt(ParseState *pstate, RetrieveStmt *stmt)
/* fix where clause */
qry->qual = transformWhereClause(pstate, stmt->whereClause);
/* check subselect clause */
if (stmt->unionClause)
{
elog(NOTICE, "UNION not yet supported; using first SELECT only", NULL);
/* XXX HACK just playing with union clause - thomas 1997-12-19 */
if ((qry->uniqueFlag == NULL)
&& (! ((SubSelect *)lfirst(stmt->unionClause))->unionall))
qry->uniqueFlag = "*";
}
/* check subselect clause */
/* check having clause */
if (stmt->havingClause)
elog(NOTICE, "HAVING not yet supported; ignore clause", NULL);
@ -842,7 +831,6 @@ transformSelectStmt(ParseState *pstate, RetrieveStmt *stmt)
qry->targetList,
qry->uniqueFlag);
/* fix group by clause */
qry->groupClause = transformGroupClause(pstate,
stmt->groupClause,
qry->targetList);
@ -851,6 +839,20 @@ transformSelectStmt(ParseState *pstate, RetrieveStmt *stmt)
if (pstate->p_numAgg > 0)
finalizeAggregates(pstate, qry);
if (stmt->unionClause)
{
List *ulist = NIL;
QueryTreeList *qlist;
int i;
qlist = parse_analyze(stmt->unionClause);
for (i=0; i < qlist->len; i++)
ulist = lappend(ulist, qlist->qtrees[i]);
qry->unionClause = ulist;
}
else
qry->unionClause = NULL;
return (Query *) qry;
}

26
src/backend/parser/gram.y
View File

@ -10,7 +10,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 1.80 1997/12/23 19:47:32 thomas Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 1.81 1997/12/24 06:06:26 momjian Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@ -120,11 +120,13 @@ Oid param_type(int t); /* used in parse_expr.c */
ProcedureStmt, RecipeStmt, RemoveAggrStmt, RemoveOperStmt,
RemoveFuncStmt, RemoveStmt,
RenameStmt, RevokeStmt, RuleStmt, TransactionStmt, ViewStmt, LoadStmt,
CreatedbStmt, DestroydbStmt, VacuumStmt, RetrieveStmt, CursorStmt,
ReplaceStmt, AppendStmt, NotifyStmt, DeleteStmt, ClusterStmt,
CreatedbStmt, DestroydbStmt, VacuumStmt, CursorStmt, SubSelect,
ReplaceStmt, AppendStmt, RetrieveStmt, NotifyStmt, DeleteStmt, ClusterStmt,
ExplainStmt, VariableSetStmt, VariableShowStmt, VariableResetStmt,
CreateUserStmt, AlterUserStmt, DropUserStmt
%type <rtstmt>
%type <str> opt_database, location
%type <pboolean> user_createdb_clause, user_createuser_clause
@ -132,7 +134,6 @@ Oid param_type(int t); /* used in parse_expr.c */
%type <str> user_valid_clause
%type <list> user_group_list, user_group_clause
%type <node> SubSelect
%type <str> join_expr, join_outer, join_spec
%type <boolean> TriggerActionTime, TriggerForSpec, PLangTrusted
@ -1049,19 +1050,10 @@ OptArchiveType: ARCHIVE '=' NONE { }
CreateAsStmt: CREATE TABLE relation_name OptCreateAs AS SubSelect
{
RetrieveStmt *n = makeNode(RetrieveStmt);
SubSelect *s = (SubSelect *)$6;
n->unique = s->unique;
n->targetList = s->targetList;
RetrieveStmt *n = (RetrieveStmt *)$6;
if ($4 != NIL)
mapTargetColumns($4, n->targetList);
n->into = $3;
n->fromClause = s->fromClause;
n->whereClause = s->whereClause;
n->groupClause = s->groupClause;
n->havingClause = s->havingClause;
n->unionClause = NULL;
n->sortClause = NULL;
$$ = (Node *)n;
}
;
@ -2291,7 +2283,7 @@ RetrieveStmt: SELECT opt_unique res_target_list2
union_clause: UNION opt_union select_list
{
SubSelect *n = lfirst($3);
RetrieveStmt *n = (RetrieveStmt *)lfirst($3);
n->unionall = $2;
$$ = $3;
}
@ -2301,7 +2293,7 @@ union_clause: UNION opt_union select_list
select_list: select_list UNION opt_union SubSelect
{
SubSelect *n = (SubSelect *)$4;
RetrieveStmt *n = (RetrieveStmt *)$4;
n->unionall = $3;
$$ = lappend($1, $4);
}
@ -2313,7 +2305,7 @@ SubSelect: SELECT opt_unique res_target_list2
from_clause where_clause
group_clause having_clause
{
SubSelect *n = makeNode(SubSelect);
RetrieveStmt *n = makeNode(RetrieveStmt);
n->unique = $2;
n->unionall = FALSE;
n->targetList = $3;

20
src/include/nodes/parsenodes.h
View File

@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: parsenodes.h,v 1.38 1997/12/23 19:58:12 thomas Exp $
* $Id: parsenodes.h,v 1.39 1997/12/24 06:06:53 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -58,6 +58,8 @@ typedef struct Query
int qry_numAgg; /* number of aggregates in the target list */
Aggreg **qry_aggs; /* the aggregates */
List *unionClause; /* unions are linked under the previous query */
/* internal to planner */
List *base_relation_list_; /* base relation list */
List *join_relation_list_; /* list of relations */
@ -634,6 +636,7 @@ typedef struct RetrieveStmt
Node *havingClause; /* having conditional-expression */
List *unionClause; /* union subselect parameters */
List *sortClause; /* sort clause (a list of SortGroupBy's) */
int unionall; /* union without unique sort */
} RetrieveStmt;
@ -641,21 +644,6 @@ typedef struct RetrieveStmt
* Supporting data structures for Parse Trees
****************************************************************************/
/*
* SubSelect - specifies subselect parameters
*/
typedef struct SubSelect
{
NodeTag type;
char *unique; /* NULL, '*', or unique attribute name */
int unionall; /* union without unique sort */
List *targetList; /* the target list (of ResTarget) */
List *fromClause; /* the from clause */
Node *whereClause; /* qualifications */
List *groupClause; /* group by clause */
Node *havingClause; /* having conditional-expression */
} SubSelect;
/*
* TypeName - specifies a type in definitions
*/

4
src/include/optimizer/prep.h
View File

@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: prep.h,v 1.9 1997/12/20 07:59:44 momjian Exp $
* $Id: prep.h,v 1.10 1997/12/24 06:06:58 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -32,7 +32,7 @@ extern List *preprocess_targetlist(List *tlist, int command_type,
*/
typedef enum UnionFlag
{
INHERITS_FLAG, VERSION_FLAG
INHERITS_FLAG, UNION_FLAG, VERSION_FLAG
} UnionFlag;
extern List *find_all_inheritors(List *unexamined_relids,