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Implement subselects in target lists. Also, relax requirement that 

subselects can only appear on the righthand side of a binary operator.
That's still true for quantified predicates like x = ANY (SELECT ...),
but a subselect that delivers a single result can now appear anywhere
in an expression.  This is implemented by changing EXPR_SUBLINK sublinks
to represent just the (SELECT ...) expression, without any 'left hand
side' or combining operator --- so they're now more like EXISTS_SUBLINK.
To handle the case of '(x, y, z) = (SELECT ...)', I added a new sublink
type MULTIEXPR_SUBLINK, which acts just like EXPR_SUBLINK used to.
But the grammar will only generate one for a multiple-left-hand-side
row expression.
This commit is contained in:
Tom Lane 1999-11-15 02:00:15 +00:00
parent 1ecb129d20
commit f68e11f373
12 changed files with 364 additions and 566 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

70
src/backend/executor/nodeSubplan.c
View File

@ -3,6 +3,11 @@
* nodeSubplan.c
* routines to support subselects
*
* Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/executor/nodeSubplan.c,v 1.16 1999/11/15 02:00:01 tgl Exp $
*
*-------------------------------------------------------------------------
*/
/*
@ -68,19 +73,17 @@ ExecSubPlan(SubPlan *node, List *pvar, ExprContext *econtext, bool *isNull)
* within a tuple (if there are multiple columns) using OR semantics
* if "useor" is true, AND semantics if not. We then combine results
* across tuples (if the subplan produces more than one) using OR
* semantics for ANY_SUBLINK or AND semantics for ALL_SUBLINK. NULL
* results from the combining operators are handled according to the
* usual SQL semantics for OR and AND. The result for no input
* tuples is FALSE for ANY_SUBLINK, TRUE for ALL_SUBLINK.
* semantics for ANY_SUBLINK or AND semantics for ALL_SUBLINK.
* (MULTIEXPR_SUBLINK doesn't allow multiple tuples from the subplan.)
* NULL results from the combining operators are handled according to
* the usual SQL semantics for OR and AND. The result for no input
* tuples is FALSE for ANY_SUBLINK, TRUE for ALL_SUBLINK, NULL for
* MULTIEXPR_SUBLINK.
*
* For EXPR_SUBLINK we require the subplan to produce no more than one
* tuple, else an error is raised. If zero tuples are produced, we
* return NULL. (XXX it would probably be more correct to evaluate
* the combining operator with a NULL input?) Assuming we get a tuple:
* if there is only one column then we just return its result as-is, NULL
* or otherwise. If there is more than one column we combine the results
* per "useor" --- this only makes sense if the combining operators yield
* boolean, and we assume the parser has checked that.
* return NULL. Assuming we get a tuple, we just return its first
* column (there can be only one non-junk column in this case).
*/
result = (Datum) (subLinkType == ALL_SUBLINK ? true : false);
*isNull = false;
@ -98,13 +101,29 @@ ExecSubPlan(SubPlan *node, List *pvar, ExprContext *econtext, bool *isNull)
if (subLinkType == EXISTS_SUBLINK)
return (Datum) true;
/* cannot allow multiple input tuples for EXPR sublink */
if (subLinkType == EXPR_SUBLINK && found)
if (subLinkType == EXPR_SUBLINK)
{
/* cannot allow multiple input tuples for EXPR sublink */
if (found)
elog(ERROR, "ExecSubPlan: more than one tuple returned by expression subselect");
found = true;
/* XXX need to copy tuple in case pass by ref */
/* XXX need to ref-count the tuple to avoid mem leak! */
tup = heap_copytuple(tup);
result = heap_getattr(tup, col, tdesc, isNull);
/* keep scanning subplan to make sure there's only one tuple */
continue;
}
/* cannot allow multiple input tuples for MULTIEXPR sublink either */
if (subLinkType == MULTIEXPR_SUBLINK && found)
elog(ERROR, "ExecSubPlan: more than one tuple returned by expression subselect");
found = true;
/* iterate over combining operators for columns of tuple */
/* For ALL, ANY, and MULTIEXPR sublinks, iterate over combining
* operators for columns of tuple.
*/
foreach(lst, sublink->oper)
{
Expr *expr = (Expr *) lfirst(lst);
@ -193,7 +212,7 @@ ExecSubPlan(SubPlan *node, List *pvar, ExprContext *econtext, bool *isNull)
}
else
{
/* must be EXPR_SUBLINK */
/* must be MULTIEXPR_SUBLINK */
result = rowresult;
*isNull = rownull;
}
@ -202,9 +221,10 @@ ExecSubPlan(SubPlan *node, List *pvar, ExprContext *econtext, bool *isNull)
if (!found)
{
/* deal with empty subplan result. result/isNull were previously
* initialized correctly for all sublink types except EXPR.
* initialized correctly for all sublink types except EXPR and
* MULTIEXPR; for those, return NULL.
*/
if (subLinkType == EXPR_SUBLINK)
if (subLinkType == EXPR_SUBLINK || subLinkType == MULTIEXPR_SUBLINK)
{
result = (Datum) false;
*isNull = true;
@ -242,7 +262,7 @@ ExecInitSubPlan(SubPlan *node, EState *estate, Plan *parent)
* If this plan is un-correlated or undirect correlated one and want
* to set params for parent plan then prepare parameters.
*/
if (node->setParam != NULL)
if (node->setParam != NIL)
{
List *lst;
@ -293,14 +313,6 @@ ExecSetParamPlan(SubPlan *node)
TupleDesc tdesc = slot->ttc_tupleDescriptor;
int i = 1;
if (sublink->subLinkType == EXPR_SUBLINK && found)
{
elog(ERROR, "ExecSetParamPlan: more than one tuple returned by expression subselect");
return;
}
found = true;
if (sublink->subLinkType == EXISTS_SUBLINK)
{
ParamExecData *prm = &(plan->state->es_param_exec_vals[lfirsti(node->setParam)]);
@ -308,9 +320,17 @@ ExecSetParamPlan(SubPlan *node)
prm->execPlan = NULL;
prm->value = (Datum) true;
prm->isnull = false;
found = true;
break;
}
if (found &&
(sublink->subLinkType == EXPR_SUBLINK ||
sublink->subLinkType == MULTIEXPR_SUBLINK))
elog(ERROR, "ExecSetParamPlan: more than one tuple returned by expression subselect");
found = true;
/*
* If this is uncorrelated subquery then its plan will be closed
* (see below) and this tuple will be free-ed - bad for not byval

14
src/backend/nodes/copyfuncs.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.94 1999/11/01 05:15:13 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.95 1999/11/15 02:00:01 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -86,10 +86,11 @@ CopyPlanFields(Plan *from, Plan *newnode)
newnode->locParam = listCopy(from->locParam);
newnode->chgParam = listCopy(from->chgParam);
Node_Copy(from, newnode, initPlan);
if (from->subPlan != NULL)
newnode->subPlan = SS_pull_subplan((Node *) newnode->qual);
if (from->subPlan != NIL)
newnode->subPlan = nconc(SS_pull_subplan((Node *) newnode->targetlist),
SS_pull_subplan((Node *) newnode->qual));
else
newnode->subPlan = NULL;
newnode->subPlan = NIL;
newnode->nParamExec = from->nParamExec;
}
@ -137,8 +138,9 @@ _copyResult(Result *from)
* We must add subplans in resconstantqual to the new plan's subPlan
* list
*/
newnode->plan.subPlan = nconc(newnode->plan.subPlan,
SS_pull_subplan(newnode->resconstantqual));
if (from->plan.subPlan != NIL)
newnode->plan.subPlan = nconc(newnode->plan.subPlan,
SS_pull_subplan(newnode->resconstantqual));
return newnode;
}

18
src/backend/optimizer/plan/planmain.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planmain.c,v 1.46 1999/10/07 04:23:06 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planmain.c,v 1.47 1999/11/15 02:00:07 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -87,9 +87,25 @@ query_planner(Query *root,
tlist = (List *) SS_replace_correlation_vars((Node *) tlist);
qual = (List *) SS_replace_correlation_vars((Node *) qual);
}
/* Expand SubLinks to SubPlans */
if (root->hasSubLinks)
{
tlist = (List *) SS_process_sublinks((Node *) tlist);
qual = (List *) SS_process_sublinks((Node *) qual);
if (root->groupClause != NIL)
{
/*
* Check for ungrouped variables passed to subplans.
* Note we do NOT do this for subplans in WHERE; it's legal
* there because WHERE is evaluated pre-GROUP.
*/
if (check_subplans_for_ungrouped_vars((Node *) tlist,
root->groupClause,
tlist))
elog(ERROR, "Sub-SELECT must use only GROUPed attributes from outer SELECT");
}
}
/*
* If the query contains no relation references at all, it must be

12
src/backend/optimizer/plan/planner.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.70 1999/10/07 04:23:06 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.71 1999/11/15 02:00:08 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -343,17 +343,11 @@ union_planner(Query *parse)
{
/* Expand SubLinks to SubPlans */
parse->havingQual = SS_process_sublinks(parse->havingQual);
/*
* Check for ungrouped variables passed to subplans. (Probably
* this should be done for the targetlist as well??? But we
* should NOT do it for the WHERE qual, since WHERE is
* evaluated pre-GROUP.)
*/
/* Check for ungrouped variables passed to subplans */
if (check_subplans_for_ungrouped_vars(parse->havingQual,
parse->groupClause,
parse->targetList))
elog(ERROR, "Sub-SELECT in HAVING clause must use only GROUPed attributes from outer SELECT");
elog(ERROR, "Sub-SELECT must use only GROUPed attributes from outer SELECT");
}
}

134
src/backend/optimizer/plan/subselect.c
View File

@ -6,7 +6,7 @@
* Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/subselect.c,v 1.24 1999/08/25 23:21:39 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/plan/subselect.c,v 1.25 1999/11/15 02:00:08 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -173,10 +173,43 @@ make_subplan(SubLink *slink)
}
/*
* Un-correlated or undirect correlated plans of EXISTS or EXPR types
* can be used as initPlans...
* Un-correlated or undirect correlated plans of EXISTS, EXPR, or
* MULTIEXPR types can be used as initPlans. For EXISTS or EXPR,
* we just produce a Param referring to the result of evaluating the
* initPlan. For MULTIEXPR, we must build an AND or OR-clause of the
* individual comparison operators, using the appropriate lefthand
* side expressions and Params for the initPlan's target items.
*/
if (node->parParam == NULL && slink->subLinkType == EXPR_SUBLINK)
if (node->parParam == NIL && slink->subLinkType == EXISTS_SUBLINK)
{
Var *var = makeVar(0, 0, BOOLOID, -1, 0);
Param *prm = makeNode(Param);
prm->paramkind = PARAM_EXEC;
prm->paramid = (AttrNumber) new_param(var, PlannerQueryLevel);
prm->paramtype = var->vartype;
pfree(var); /* var is only needed for new_param */
node->setParam = lappendi(node->setParam, prm->paramid);
PlannerInitPlan = lappend(PlannerInitPlan, node);
result = (Node *) prm;
}
else if (node->parParam == NIL && slink->subLinkType == EXPR_SUBLINK)
{
TargetEntry *te = lfirst(plan->targetlist);
/* need a var node just to pass to new_param()... */
Var *var = makeVar(0, 0, te->resdom->restype,
te->resdom->restypmod, 0);
Param *prm = makeNode(Param);
prm->paramkind = PARAM_EXEC;
prm->paramid = (AttrNumber) new_param(var, PlannerQueryLevel);
prm->paramtype = var->vartype;
pfree(var); /* var is only needed for new_param */
node->setParam = lappendi(node->setParam, prm->paramid);
PlannerInitPlan = lappend(PlannerInitPlan, node);
result = (Node *) prm;
}
else if (node->parParam == NIL && slink->subLinkType == MULTIEXPR_SUBLINK)
{
List *newoper = NIL;
int i = 0;
@ -202,6 +235,7 @@ make_subplan(SubLink *slink)
prm->paramkind = PARAM_EXEC;
prm->paramid = (AttrNumber) new_param(var, PlannerQueryLevel);
prm->paramtype = var->vartype;
pfree(var); /* var is only needed for new_param */
Assert(IsA(oper, Oper));
tup = get_operator_tuple(oper->opno);
@ -219,7 +253,6 @@ make_subplan(SubLink *slink)
(Var *) left,
(Var *) right));
node->setParam = lappendi(node->setParam, prm->paramid);
pfree(var);
i++;
}
slink->oper = newoper;
@ -231,19 +264,6 @@ make_subplan(SubLink *slink)
else
result = (Node *) lfirst(newoper);
}
else if (node->parParam == NULL && slink->subLinkType == EXISTS_SUBLINK)
{
Var *var = makeVar(0, 0, BOOLOID, -1, 0);
Param *prm = makeNode(Param);
prm->paramkind = PARAM_EXEC;
prm->paramid = (AttrNumber) new_param(var, PlannerQueryLevel);
prm->paramtype = var->vartype;
node->setParam = lappendi(node->setParam, prm->paramid);
pfree(var);
PlannerInitPlan = lappend(PlannerInitPlan, node);
result = (Node *) prm;
}
else
{
/* make expression of SUBPLAN type */
@ -333,7 +353,8 @@ set_unioni(List *l1, List *l2)
/*
* finalize_primnode: build lists of subplans and params appearing
* in the given expression tree.
* in the given expression tree. NOTE: items are added to lists passed in,
* so caller must initialize lists to NIL before first call!
*/
typedef struct finalize_primnode_results {
@ -341,20 +362,8 @@ typedef struct finalize_primnode_results {
List *paramids; /* List of PARAM_EXEC paramids found */
} finalize_primnode_results;
static bool finalize_primnode_walker(Node *node,
finalize_primnode_results *results);
static void
finalize_primnode(Node *expr, finalize_primnode_results *results)
{
results->subplans = NIL; /* initialize */
results->paramids = NIL;
(void) finalize_primnode_walker(expr, results);
}
static bool
finalize_primnode_walker(Node *node,
finalize_primnode_results *results)
finalize_primnode(Node *node, finalize_primnode_results *results)
{
if (node == NULL)
return false;
@ -389,7 +398,7 @@ finalize_primnode_walker(Node *node,
}
/* fall through to recurse into subplan args */
}
return expression_tree_walker(node, finalize_primnode_walker,
return expression_tree_walker(node, finalize_primnode,
(void *) results);
}
@ -443,7 +452,7 @@ process_sublinks_mutator(Node *node, void *context)
{
SubLink *sublink = (SubLink *) node;
/* First, scan the lefthand-side expressions.
/* First, scan the lefthand-side expressions, if any.
* This is a tad klugy since we modify the input SubLink node,
* but that should be OK (make_subplan does it too!)
*/
@ -475,23 +484,28 @@ SS_finalize_plan(Plan *plan)
List *lst;
if (plan == NULL)
return NULL;
return NIL;
/* Find params in targetlist, make sure there are no subplans there */
finalize_primnode((Node *) plan->targetlist, &results);
Assert(results.subplans == NIL);
/* From here on, we invoke finalize_primnode_walker not finalize_primnode,
* so that results.paramids lists are automatically merged together and
* we don't have to do it the hard way. But when recursing to self,
* we do have to merge the lists. Oh well.
results.subplans = NIL; /* initialize lists to NIL */
results.paramids = NIL;
/*
* When we call finalize_primnode, results.paramids lists are
* automatically merged together. But when recursing to self,
* we have to do it the hard way. We want the paramids list
* to include params in subplans as well as at this level.
* (We don't care about finding subplans of subplans, though.)
*/
/* Find params and subplans in targetlist and qual */
finalize_primnode((Node *) plan->targetlist, &results);
finalize_primnode((Node *) plan->qual, &results);
/* Check additional node-type-specific fields */
switch (nodeTag(plan))
{
case T_Result:
finalize_primnode_walker(((Result *) plan)->resconstantqual,
&results);
/* results.subplans is NOT necessarily empty here ... */
finalize_primnode(((Result *) plan)->resconstantqual,
&results);
break;
case T_Append:
@ -501,33 +515,26 @@ SS_finalize_plan(Plan *plan)
break;
case T_IndexScan:
finalize_primnode_walker((Node *) ((IndexScan *) plan)->indxqual,
&results);
Assert(results.subplans == NIL);
finalize_primnode((Node *) ((IndexScan *) plan)->indxqual,
&results);
break;
case T_MergeJoin:
finalize_primnode_walker((Node *) ((MergeJoin *) plan)->mergeclauses,
&results);
Assert(results.subplans == NIL);
finalize_primnode((Node *) ((MergeJoin *) plan)->mergeclauses,
&results);
break;
case T_HashJoin:
finalize_primnode_walker((Node *) ((HashJoin *) plan)->hashclauses,
&results);
Assert(results.subplans == NIL);
finalize_primnode((Node *) ((HashJoin *) plan)->hashclauses,
&results);
break;
case T_Hash:
finalize_primnode_walker((Node *) ((Hash *) plan)->hashkey,
&results);
Assert(results.subplans == NIL);
finalize_primnode((Node *) ((Hash *) plan)->hashkey,
&results);
break;
case T_Agg:
/* XXX Code used to reject subplans in Aggref args; needed?? */
break;
case T_SeqScan:
case T_NestLoop:
case T_Material:
@ -539,12 +546,9 @@ SS_finalize_plan(Plan *plan)
default:
elog(ERROR, "SS_finalize_plan: node %d unsupported",
nodeTag(plan));
return NULL;
}
finalize_primnode_walker((Node *) plan->qual, &results);
/* subplans are OK in the qual... */
/* Process left and right subplans, if any */
results.paramids = set_unioni(results.paramids,
SS_finalize_plan(plan->lefttree));
results.paramids = set_unioni(results.paramids,

7
src/backend/parser/analyze.c
View File

@ -5,7 +5,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: analyze.c,v 1.123 1999/11/07 23:08:10 momjian Exp $
* $Id: analyze.c,v 1.124 1999/11/15 02:00:09 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -231,11 +231,11 @@ transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt)
/* fix where clause */
qry->qual = transformWhereClause(pstate, stmt->whereClause, NULL);
qry->hasSubLinks = pstate->p_hasSubLinks;
qry->rtable = pstate->p_rtable;
qry->resultRelation = refnameRangeTablePosn(pstate, stmt->relname, NULL);
qry->hasSubLinks = pstate->p_hasSubLinks;
qry->hasAggs = pstate->p_hasAggs;
if (pstate->p_hasAggs)
parseCheckAggregates(pstate, qry);
@ -423,6 +423,9 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
if (stmt->forUpdate != NULL)
transformForUpdate(qry, stmt->forUpdate);
/* in case of subselects in default clauses... */
qry->hasSubLinks = pstate->p_hasSubLinks;
return (Query *) qry;
}

405
src/backend/parser/gram.y
View File

@ -10,7 +10,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.113 1999/10/29 23:52:20 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.114 1999/11/15 02:00:10 tgl Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@ -53,11 +53,12 @@
#include "mb/pg_wchar.h"
#endif
extern List *parsetree; /* final parse result is delivered here */
static char saved_relname[NAMEDATALEN]; /* need this for complex attributes */
static bool QueryIsRule = FALSE;
static Oid *param_type_info;
static int pfunc_num_args;
extern List *parsetree;
/*
@ -75,8 +76,6 @@ static void mapTargetColumns(List *source, List *target);
static void param_type_init(Oid *typev, int nargs);
static Node *doNegate(Node *n);
Oid param_type(int t); /* used in parse_expr.c */
/* old versions of flex define this as a macro */
#if defined(yywrap)
#undef yywrap
@ -178,7 +177,7 @@ Oid param_type(int t); /* used in parse_expr.c */
%type <boolean> TriggerForOpt, TriggerForType, OptTemp, OptTempType, OptTempScope
%type <list> for_update_clause, update_list
%type <boolean> opt_union
%type <boolean> opt_all
%type <boolean> opt_table
%type <boolean> opt_trans
@ -1097,11 +1096,18 @@ OptInherit: INHERITS '(' relation_name_list ')' { $$ = $3; }
| /*EMPTY*/ { $$ = NIL; }
;
CreateAsStmt: CREATE OptTemp TABLE relation_name OptCreateAs AS SubSelect
/*
* Note: CREATE TABLE ... AS SELECT ... is just another spelling for
* SELECT ... INTO.
*/
CreateAsStmt: CREATE OptTemp TABLE relation_name OptCreateAs AS SelectStmt
{
SelectStmt *n = (SelectStmt *)$7;
if ($5 != NIL)
mapTargetColumns($5, n->targetList);
if (n->into != NULL)
elog(ERROR,"CREATE TABLE/AS SELECT may not specify INTO");
n->istemp = $2;
n->into = $4;
$$ = (Node *)n;
@ -2861,7 +2867,7 @@ select_clause: '(' select_clause ')'
$$ = (Node *)makeA_Expr(AND,NULL,$1,
makeA_Expr(NOT,NULL,NULL,$3));
}
| select_clause UNION opt_union select_clause
| select_clause UNION opt_all select_clause
{
if (IsA($4, SelectStmt))
{
@ -2919,7 +2925,7 @@ opt_table: TABLE { $$ = TRUE; }
| /*EMPTY*/ { $$ = FALSE; }
;
opt_union: ALL { $$ = TRUE; }
opt_all: ALL { $$ = TRUE; }
| /*EMPTY*/ { $$ = FALSE; }
;
@ -3590,16 +3596,13 @@ a_expr_or_null: a_expr
* Define row_descriptor to allow yacc to break the reduce/reduce conflict
* with singleton expressions.
* Eliminated lots of code by defining row_op and sub_type clauses.
* However, can not consolidate EXPR_LINK case with others subselects
* due to shift/reduce conflict with the non-subselect clause (the parser
* would have to look ahead more than one token to resolve the conflict).
* - thomas 1998-05-09
*/
row_expr: '(' row_descriptor ')' IN '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = $2;
n->oper = lcons("=",NIL);
n->oper = lcons("=", NIL);
n->useor = false;
n->subLinkType = ANY_SUBLINK;
n->subselect = $6;
@ -3609,7 +3612,7 @@ row_expr: '(' row_descriptor ')' IN '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = $2;
n->oper = lcons("<>",NIL);
n->oper = lcons("<>", NIL);
n->useor = true;
n->subLinkType = ALL_SUBLINK;
n->subselect = $7;
@ -3637,7 +3640,7 @@ row_expr: '(' row_descriptor ')' IN '(' SubSelect ')'
n->useor = true;
else
n->useor = false;
n->subLinkType = EXPR_SUBLINK;
n->subLinkType = MULTIEXPR_SUBLINK;
n->subselect = $6;
$$ = (Node *)n;
}
@ -3933,16 +3936,6 @@ a_expr: attr
n->args = NIL;
$$ = (Node *)n;
}
| EXISTS '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = NIL;
n->useor = false;
n->oper = NIL;
n->subLinkType = EXISTS_SUBLINK;
n->subselect = $3;
$$ = (Node *)n;
}
| EXTRACT '(' extract_list ')'
{
FuncCall *n = makeNode(FuncCall);
@ -4065,7 +4058,7 @@ a_expr: attr
{
SubLink *n = (SubLink *)$4;
n->lefthand = lcons($1, NIL);
n->oper = lcons("=",NIL);
n->oper = lcons("=", NIL);
n->useor = false;
n->subLinkType = ANY_SUBLINK;
$$ = (Node *)n;
@ -4092,7 +4085,7 @@ a_expr: attr
{
SubLink *n = (SubLink *)$5;
n->lefthand = lcons($1, NIL);
n->oper = lcons("<>",NIL);
n->oper = lcons("<>", NIL);
n->useor = false;
n->subLinkType = ALL_SUBLINK;
$$ = (Node *)n;
@ -4112,334 +4105,34 @@ a_expr: attr
$$ = n;
}
}
| a_expr Op '(' SubSelect ')'
| a_expr row_op sub_type '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons($2,NIL);
n->lefthand = lcons($1, NIL);
n->oper = lcons($2, NIL);
n->useor = false; /* doesn't matter since only one col */
n->subLinkType = $3;
n->subselect = $5;
$$ = (Node *)n;
}
| EXISTS '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = NIL;
n->oper = NIL;
n->useor = false;
n->subLinkType = EXISTS_SUBLINK;
n->subselect = $3;
$$ = (Node *)n;
}
| '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = NIL;
n->oper = NIL;
n->useor = false;
n->subLinkType = EXPR_SUBLINK;
n->subselect = $4;
$$ = (Node *)n;
}
| a_expr '+' '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons("+",NIL);
n->useor = false;
n->subLinkType = EXPR_SUBLINK;
n->subselect = $4;
$$ = (Node *)n;
}
| a_expr '-' '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons("-",NIL);
n->useor = false;
n->subLinkType = EXPR_SUBLINK;
n->subselect = $4;
$$ = (Node *)n;
}
| a_expr '*' '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons("*",NIL);
n->useor = false;
n->subLinkType = EXPR_SUBLINK;
n->subselect = $4;
$$ = (Node *)n;
}
| a_expr '/' '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons("/",NIL);
n->useor = false;
n->subLinkType = EXPR_SUBLINK;
n->subselect = $4;
$$ = (Node *)n;
}
| a_expr '%' '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons("%",NIL);
n->useor = false;
n->subLinkType = EXPR_SUBLINK;
n->subselect = $4;
$$ = (Node *)n;
}
| a_expr '^' '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons("^",NIL);
n->useor = false;
n->subLinkType = EXPR_SUBLINK;
n->subselect = $4;
$$ = (Node *)n;
}
| a_expr '|' '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons("|",NIL);
n->useor = false;
n->subLinkType = EXPR_SUBLINK;
n->subselect = $4;
$$ = (Node *)n;
}
| a_expr '<' '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons("<",NIL);
n->useor = false;
n->subLinkType = EXPR_SUBLINK;
n->subselect = $4;
$$ = (Node *)n;
}
| a_expr '>' '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons(">",NIL);
n->useor = false;
n->subLinkType = EXPR_SUBLINK;
n->subselect = $4;
$$ = (Node *)n;
}
| a_expr '=' '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons("=",NIL);
n->useor = false;
n->subLinkType = EXPR_SUBLINK;
n->subselect = $4;
$$ = (Node *)n;
}
| a_expr Op ANY '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1,NIL);
n->oper = lcons($2,NIL);
n->useor = false;
n->subLinkType = ANY_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr '+' ANY '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1,NIL);
n->oper = lcons("+",NIL);
n->useor = false;
n->subLinkType = ANY_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr '-' ANY '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1,NIL);
n->oper = lcons("-",NIL);
n->useor = false;
n->subLinkType = ANY_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr '*' ANY '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1,NIL);
n->oper = lcons("*",NIL);
n->useor = false;
n->subLinkType = ANY_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr '/' ANY '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1,NIL);
n->oper = lcons("/",NIL);
n->useor = false;
n->subLinkType = ANY_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr '%' ANY '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1,NIL);
n->oper = lcons("%",NIL);
n->useor = false;
n->subLinkType = ANY_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr '^' ANY '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1,NIL);
n->oper = lcons("^",NIL);
n->useor = false;
n->subLinkType = ANY_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr '|' ANY '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1,NIL);
n->oper = lcons("|",NIL);
n->useor = false;
n->subLinkType = ANY_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr '<' ANY '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1,NIL);
n->oper = lcons("<",NIL);
n->useor = false;
n->subLinkType = ANY_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr '>' ANY '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1,NIL);
n->oper = lcons(">",NIL);
n->useor = false;
n->subLinkType = ANY_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr '=' ANY '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1,NIL);
n->oper = lcons("=",NIL);
n->useor = false;
n->subLinkType = ANY_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr Op ALL '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons($2,NIL);
n->useor = false;
n->subLinkType = ALL_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr '+' ALL '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons("+",NIL);
n->useor = false;
n->subLinkType = ALL_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr '-' ALL '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons("-",NIL);
n->useor = false;
n->subLinkType = ALL_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr '*' ALL '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons("*",NIL);
n->useor = false;
n->subLinkType = ALL_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr '/' ALL '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons("/",NIL);
n->useor = false;
n->subLinkType = ALL_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr '%' ALL '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons("%",NIL);
n->useor = false;
n->subLinkType = ALL_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr '^' ALL '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons("^",NIL);
n->useor = false;
n->subLinkType = ALL_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr '|' ALL '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons("|",NIL);
n->useor = false;
n->subLinkType = ALL_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr '<' ALL '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons("<",NIL);
n->useor = false;
n->subLinkType = ALL_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr '>' ALL '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons(">",NIL);
n->useor = false;
n->subLinkType = ALL_SUBLINK;
n->subselect = $5;
$$ = (Node *)n;
}
| a_expr '=' ALL '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = lcons($1, NULL);
n->oper = lcons("=",NIL);
n->useor = false;
n->subLinkType = ALL_SUBLINK;
n->subselect = $5;
n->subselect = $2;
$$ = (Node *)n;
}
| a_expr AND a_expr
@ -4702,6 +4395,16 @@ b_expr: attr
n->args = $3;
$$ = (Node *)n;
}
| '(' SubSelect ')'
{
SubLink *n = makeNode(SubLink);
n->lefthand = NIL;
n->oper = NIL;
n->useor = false;
n->subLinkType = EXPR_SUBLINK;
n->subselect = $2;
$$ = (Node *)n;
}
;
opt_indirection: '[' a_expr ']' opt_indirection
@ -5345,8 +5048,6 @@ mapTargetColumns(List *src, List *dst)
src = lnext(src);
dst = lnext(dst);
}
return;
} /* mapTargetColumns() */

45
src/backend/parser/parse_expr.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/parse_expr.c,v 1.58 1999/09/13 04:14:56 thomas Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/parse_expr.c,v 1.59 1999/11/15 02:00:10 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -220,8 +220,30 @@ transformExpr(ParseState *pstate, Node *expr, int precedence)
sublink->lefthand = NIL;
sublink->oper = NIL;
}
else if (sublink->subLinkType == EXPR_SUBLINK)
{
List *tlist = qtree->targetList;
/* Make sure the subselect delivers a single column
* (ignoring resjunk targets).
*/
if (tlist == NIL ||
((TargetEntry *) lfirst(tlist))->resdom->resjunk)
elog(ERROR, "parser: subselect must have a field");
while ((tlist = lnext(tlist)) != NIL)
{
if (! ((TargetEntry *) lfirst(tlist))->resdom->resjunk)
elog(ERROR, "parser: subselect must have only one field");
}
/* EXPR needs no lefthand or combining operator.
* These fields should be NIL already, but make sure.
*/
sublink->lefthand = NIL;
sublink->oper = NIL;
}
else
{
/* ALL, ANY, or MULTIEXPR: generate operator list */
char *op = lfirst(sublink->oper);
List *left_list = sublink->lefthand;
List *right_list = qtree->targetList;
@ -231,9 +253,10 @@ transformExpr(ParseState *pstate, Node *expr, int precedence)
lfirst(elist) = transformExpr(pstate, lfirst(elist),
precedence);
if (length(left_list) > 1 &&
/* Combining operators other than =/<> is dubious... */
if (length(left_list) != 1 &&
strcmp(op, "=") != 0 && strcmp(op, "<>") != 0)
elog(ERROR, "parser: '%s' is not relational operator",
elog(ERROR, "parser: '%s' is not usable for row comparison",
op);
sublink->oper = NIL;
@ -266,8 +289,7 @@ transformExpr(ParseState *pstate, Node *expr, int precedence)
FALSE);
opform = (Form_pg_operator) GETSTRUCT(optup);
if (opform->oprresult != BOOLOID &&
sublink->subLinkType != EXPR_SUBLINK)
if (opform->oprresult != BOOLOID)
elog(ERROR, "parser: '%s' must return 'bool' to be used with quantified predicate subquery", op);
newop = makeOper(oprid(optup),/* opno */
@ -589,13 +611,14 @@ exprType(Node *expr)
if (sublink->subLinkType == EXPR_SUBLINK)
{
/* return the result type of the combining operator;
* should only be one...
*/
Oper *op = (Oper *) lfirst(sublink->oper);
/* get the type of the subselect's first target column */
Query *qtree = (Query *) sublink->subselect;
TargetEntry *tent;
Assert(IsA(op, Oper));
type = op->opresulttype;
if (! qtree || ! IsA(qtree, Query))
elog(ERROR, "exprType: can't get type for untransformed sublink");
tent = (TargetEntry *) lfirst(qtree->targetList);
type = tent->resdom->restype;
}
else
{

154
src/backend/rewrite/rewriteHandler.c
View File

@ -6,7 +6,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.62 1999/11/01 05:18:31 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.63 1999/11/15 02:00:03 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -56,9 +56,9 @@ static bool attribute_used(Node *node, int rt_index, int attno,
int sublevels_up);
static bool modifyAggrefUplevel(Node *node, void *context);
static bool modifyAggrefChangeVarnodes(Node *node, int rt_index, int new_index,
int sublevels_up);
int sublevels_up, int new_sublevels_up);
static Node *modifyAggrefDropQual(Node *node, Node *targetNode);
static SubLink *modifyAggrefMakeSublink(Expr *origexp, Query *parsetree);
static SubLink *modifyAggrefMakeSublink(Aggref *aggref, Query *parsetree);
static Node *modifyAggrefQual(Node *node, Query *parsetree);
static bool checkQueryHasAggs(Node *node);
static bool checkQueryHasAggs_walker(Node *node, void *context);
@ -357,6 +357,7 @@ typedef struct {
int rt_index;
int new_index;
int sublevels_up;
int new_sublevels_up;
} modifyAggrefChangeVarnodes_context;
static bool
@ -374,7 +375,7 @@ modifyAggrefChangeVarnodes_walker(Node *node,
{
var->varno = context->new_index;
var->varnoold = context->new_index;
var->varlevelsup = 0;
var->varlevelsup = context->new_sublevels_up;
}
return false;
}
@ -392,7 +393,8 @@ modifyAggrefChangeVarnodes_walker(Node *node,
if (modifyAggrefChangeVarnodes((Node *) (sub->subselect),
context->rt_index,
context->new_index,
context->sublevels_up + 1))
context->sublevels_up + 1,
context->new_sublevels_up + 1))
return true;
return false;
}
@ -418,13 +420,14 @@ modifyAggrefChangeVarnodes_walker(Node *node,
static bool
modifyAggrefChangeVarnodes(Node *node, int rt_index, int new_index,
int sublevels_up)
int sublevels_up, int new_sublevels_up)
{
modifyAggrefChangeVarnodes_context context;
context.rt_index = rt_index;
context.new_index = new_index;
context.sublevels_up = sublevels_up;
context.new_sublevels_up = new_sublevels_up;
return modifyAggrefChangeVarnodes_walker(node, &context);
}
@ -433,8 +436,13 @@ modifyAggrefChangeVarnodes(Node *node, int rt_index, int new_index,
* modifyAggrefDropQual -
* remove the pure aggref clause from a qualification
*
* targetNode is a boolean expression node somewhere within the given
* expression tree. When we find it, replace it with a constant TRUE.
* targetNode is an Aggref node somewhere within the given expression tree.
* Find the boolean operator that's presumably somewhere above it, and replace
* that whole operator expression with a constant TRUE. (This is NOT really
* quite the right thing, but it handles simple cases. This whole set of
* Aggref-in-qual routines needs to be thrown away when we can do subselects
* in FROM.)
*
* The return tree is a modified copy of the given tree; the given tree
* is not altered.
*
@ -448,14 +456,28 @@ modifyAggrefDropQual(Node *node, Node *targetNode)
if (node == NULL)
return NULL;
if (node == targetNode)
{
/* Oops, it's not inside an Expr we can rearrange... */
elog(ERROR, "Cannot handle aggregate function inserted at this place in WHERE clause");
}
if (IsA(node, Expr))
{
Expr *expr = (Expr *) node;
List *i;
if (! IsA(expr, Expr) || expr->typeOid != BOOLOID)
elog(ERROR,
"aggregate expression in qualification isn't of type bool");
return (Node *) makeConst(BOOLOID, 1, (Datum) true,
false, true, false, false);
foreach(i, expr->args)
{
if (((Node *) lfirst(i)) == targetNode)
{
/* Found the parent expression containing the Aggref */
if (expr->typeOid != BOOLOID)
elog(ERROR,
"aggregate function in qual must be argument of boolean operator");
return (Node *) makeConst(BOOLOID, 1, (Datum) true,
false, true, false, false);
}
}
/* else this isn't the expr we want, keep going */
}
return expression_tree_mutator(node, modifyAggrefDropQual,
(void *) targetNode);
@ -467,27 +489,17 @@ modifyAggrefDropQual(Node *node, Node *targetNode)
* uses an aggregate column of a view
*/
static SubLink *
modifyAggrefMakeSublink(Expr *origexp, Query *parsetree)
modifyAggrefMakeSublink(Aggref *aggref, Query *parsetree)
{
SubLink *sublink;
Query *subquery;
RangeTblEntry *rte;
Aggref *aggref;
/* target and rte point to old structures: */
Var *target;
RangeTblEntry *rte;
/* these point to newly-created structures: */
Query *subquery;
SubLink *sublink;
TargetEntry *tle;
Resdom *resdom;
Expr *exp = copyObject(origexp);
if (IsA(nth(0, exp->args), Aggref))
{
if (IsA(nth(1, exp->args), Aggref))
elog(ERROR, "rewrite: comparison of 2 aggregate columns not supported");
else
elog(ERROR, "rewrite: aggregate column of view must be at right side in qual");
/* XXX could try to commute operator, instead of failing */
}
aggref = (Aggref *) nth(1, exp->args);
target = (Var *) (aggref->target);
if (! IsA(target, Var))
elog(ERROR, "rewrite: aggregates of views only allowed on simple variables for now");
@ -504,16 +516,15 @@ modifyAggrefMakeSublink(Expr *origexp, Query *parsetree)
tle = makeNode(TargetEntry);
tle->resdom = resdom;
tle->expr = (Node *) aggref; /* note this is from the copied expr */
tle->expr = copyObject(aggref); /* make a modifiable copy! */
subquery = makeNode(Query);
sublink = makeNode(SubLink);
sublink->subLinkType = EXPR_SUBLINK;
sublink->useor = false;
/* note lefthand and oper are made from the copied expr */
sublink->lefthand = lcons(lfirst(exp->args), NIL);
sublink->oper = lcons(exp->oper, NIL);
subquery = makeNode(Query);
sublink->lefthand = NIL;
sublink->oper = NIL;
sublink->subselect = (Node *) subquery;
subquery->commandType = CMD_SELECT;
@ -526,33 +537,31 @@ modifyAggrefMakeSublink(Expr *origexp, Query *parsetree)
subquery->unionall = FALSE;
subquery->uniqueFlag = NULL;
subquery->sortClause = NULL;
subquery->rtable = lcons(rte, NIL);
subquery->rtable = lcons(copyObject(rte), NIL);
subquery->targetList = lcons(tle, NIL);
subquery->qual = modifyAggrefDropQual((Node *) parsetree->qual,
(Node *) origexp);
(Node *) aggref);
/*
* If there are still aggs in the subselect's qual, give up.
* Recursing would be a bad idea --- we'd likely produce an
* infinite recursion. This whole technique is a crock, really...
*/
if (checkQueryHasAggs(subquery->qual))
elog(ERROR, "Cannot handle aggregate function inserted at this place in WHERE clause");
elog(ERROR, "Cannot handle multiple aggregate functions in WHERE clause");
subquery->groupClause = NIL;
subquery->havingQual = NULL;
subquery->hasAggs = TRUE;
subquery->hasSubLinks = FALSE;
subquery->hasSubLinks = checkQueryHasSubLink(subquery->qual);
subquery->unionClause = NULL;
/* Increment all varlevelsup fields in the new subquery */
modifyAggrefUplevel((Node *) subquery, NULL);
/*
* Note: it might appear that we should be passing target->varlevelsup+1
* here, since modifyAggrefUplevel has increased all the varlevelsup
* values in the subquery. However, target itself is a pointer to a
* Var node in the subquery, so it's been incremented too! What a kluge
* this all is ... we need to make subquery RTEs so it can go away...
/* Replace references to the target table with correct varno.
* Note +1 here to account for effects of previous line!
*/
modifyAggrefChangeVarnodes((Node *) subquery, target->varno,
1, target->varlevelsup);
1, target->varlevelsup+1, 0);
return sublink;
}
@ -572,30 +581,17 @@ modifyAggrefQual(Node *node, Query *parsetree)
{
if (node == NULL)
return NULL;
if (IsA(node, Expr))
{
Expr *expr = (Expr *) node;
if (length(expr->args) == 2 &&
(IsA(lfirst(expr->args), Aggref) ||
IsA(lsecond(expr->args), Aggref)))
{
SubLink *sub = modifyAggrefMakeSublink(expr,
parsetree);
parsetree->hasSubLinks = true;
/* check for aggs in resulting lefthand... */
sub->lefthand = (List *) modifyAggrefQual((Node *) sub->lefthand,
parsetree);
return (Node *) sub;
}
/* otherwise, fall through and copy the expr normally */
}
if (IsA(node, Aggref))
{
/* Oops, found one that's not inside an Expr we can rearrange... */
elog(ERROR, "Cannot handle aggregate function inserted at this place in WHERE clause");
SubLink *sub = modifyAggrefMakeSublink((Aggref *) node, parsetree);
parsetree->hasSubLinks = true;
return (Node *) sub;
}
/* We do NOT recurse into subselects in this routine. It's sufficient
/*
* Otherwise, fall through and copy the expr normally.
*
* We do NOT recurse into subselects in this routine. It's sufficient
* to get rid of aggregates that are in the qual expression proper.
*/
return expression_tree_mutator(node, modifyAggrefQual,
@ -1113,7 +1109,8 @@ fireRIRrules(Query *parsetree)
if (parsetree->hasSubLinks)
fireRIRonSubselect((Node *) parsetree, NULL);
parsetree->qual = modifyAggrefQual(parsetree->qual, parsetree);
if (parsetree->hasAggs)
parsetree->qual = modifyAggrefQual(parsetree->qual, parsetree);
return parsetree;
}
@ -1577,17 +1574,22 @@ BasicQueryRewrite(Query *parsetree)
/*
* If the query was marked having aggregates, check if this is
* still true after rewriting. Ditto for sublinks.
*
* This check must get expanded when someday aggregates can appear
* somewhere else than in the targetlist or the having qual.
* still true after rewriting. Ditto for sublinks. Note there
* should be no aggs in the qual at this point.
*/
if (query->hasAggs)
query->hasAggs = checkQueryHasAggs((Node *) (query->targetList))
|| checkQueryHasAggs((Node *) (query->havingQual));
{
query->hasAggs =
checkQueryHasAggs((Node *) (query->targetList)) ||
checkQueryHasAggs((Node *) (query->havingQual));
if (checkQueryHasAggs((Node *) (query->qual)))
elog(ERROR, "BasicQueryRewrite: failed to remove aggs from qual");
}
if (query->hasSubLinks)
query->hasSubLinks = checkQueryHasSubLink((Node *) (query->qual))
|| checkQueryHasSubLink((Node *) (query->havingQual));
query->hasSubLinks =
checkQueryHasSubLink((Node *) (query->targetList)) ||
checkQueryHasSubLink((Node *) (query->qual)) ||
checkQueryHasSubLink((Node *) (query->havingQual));
results = lappend(results, query);
}

30
src/backend/utils/adt/ruleutils.c
View File

@ -3,7 +3,7 @@
* out of it's tuple
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/adt/ruleutils.c,v 1.30 1999/11/07 23:08:24 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/utils/adt/ruleutils.c,v 1.31 1999/11/15 02:00:05 tgl Exp $
*
* This software is copyrighted by Jan Wieck - Hamburg.
*
@ -1681,15 +1681,17 @@ get_sublink_expr(Node *node, deparse_context *context)
StringInfo buf = context->buf;
SubLink *sublink = (SubLink *) node;
Query *query = (Query *) (sublink->subselect);
Oper *oper;
List *l;
char *sep;
Oper *oper;
bool need_paren;
appendStringInfo(buf, "(");
if (sublink->lefthand != NULL)
if (sublink->lefthand != NIL)
{
if (length(sublink->lefthand) > 1)
need_paren = (length(sublink->lefthand) > 1);
if (need_paren)
appendStringInfo(buf, "(");
sep = "";
@ -1700,12 +1702,14 @@ get_sublink_expr(Node *node, deparse_context *context)
get_rule_expr((Node *) lfirst(l), context);
}
if (length(sublink->lefthand) > 1)
if (need_paren)
appendStringInfo(buf, ") ");
else
appendStringInfo(buf, " ");
}
need_paren = true;
switch (sublink->subLinkType)
{
case EXISTS_SUBLINK:
@ -1722,20 +1726,30 @@ get_sublink_expr(Node *node, deparse_context *context)
appendStringInfo(buf, "%s ALL ", get_opname(oper->opno));
break;
case EXPR_SUBLINK:
case MULTIEXPR_SUBLINK:
oper = (Oper *) lfirst(sublink->oper);
appendStringInfo(buf, "%s ", get_opname(oper->opno));
break;
case EXPR_SUBLINK:
need_paren = false;
break;
default:
elog(ERROR, "get_sublink_expr: unsupported sublink type %d",
sublink->subLinkType);
break;
}
appendStringInfo(buf, "(");
if (need_paren)
appendStringInfo(buf, "(");
get_query_def(query, buf, context->rangetables);
appendStringInfo(buf, "))");
if (need_paren)
appendStringInfo(buf, "))");
else
appendStringInfo(buf, ")");
}
/* ----------

6
src/include/nodes/plannodes.h
View File

@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: plannodes.h,v 1.31 1999/10/17 22:15:07 tgl Exp $
* $Id: plannodes.h,v 1.32 1999/11/15 02:00:13 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -356,8 +356,8 @@ typedef struct SubPlan
List *setParam; /* non-correlated EXPR & EXISTS subqueries
* have to set some Params for paren Plan */
List *parParam; /* indices of corr. Vars from parent plan */
SubLink *sublink; /* SubLink node for subselects in WHERE
* and HAVING */
SubLink *sublink; /* SubLink node from parser; holds info about
* what to do with subselect's results */
bool shutdown; /* shutdown plan if TRUE */
} SubPlan;

35
src/include/nodes/primnodes.h
View File

@ -6,7 +6,7 @@
*
* Copyright (c) 1994, Regents of the University of California
*
* $Id: primnodes.h,v 1.36 1999/08/25 23:21:36 tgl Exp $
* $Id: primnodes.h,v 1.37 1999/11/15 02:00:15 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -98,8 +98,7 @@ typedef struct Fjoin
* Expr
* typeOid - oid of the type of this expression
* opType - type of this expression
* oper - the Oper node if it is an OPER_EXPR or the
* Func node if it is a FUNC_EXPR
* oper - operator node if needed (Oper, Func, or SubPlan)
* args - arguments to this expression
* ----------------
*/
@ -318,12 +317,31 @@ typedef struct Aggref
/* ----------------
* SubLink
* subLinkType - EXISTS, ALL, ANY, EXPR
* useor - TRUE for <> (combine op results with "or" not "and")
* subLinkType - EXISTS, ALL, ANY, MULTIEXPR, EXPR
* useor - TRUE to combine column results with "OR" not "AND"
* lefthand - list of outer-query expressions on the left
* oper - list of Oper nodes
* oper - list of Oper nodes for combining operators
* subselect - subselect as Query* or parsetree
*
* A SubLink represents a subselect appearing in an expression, and in some
* cases also the combining operator(s) just above it. The subLinkType
* indicates the form of the expression represented:
* EXISTS_SUBLINK EXISTS(SELECT ...)
* ALL_SUBLINK (lefthand) op ALL (SELECT ...)
* ANY_SUBLINK (lefthand) op ANY (SELECT ...)
* MULTIEXPR_SUBLINK (lefthand) op (SELECT ...)
* EXPR_SUBLINK (SELECT with single targetlist item ...)
* For ALL, ANY, and MULTIEXPR, the lefthand is a list of expressions of the
* same length as the subselect's targetlist. MULTIEXPR will *always* have
* a list with more than one entry; if the subselect has just one target
* then the parser will create an EXPR_SUBLINK instead (and any operator
* above the subselect will be represented separately). Note that both
* MULTIEXPR and EXPR require the subselect to deliver only one row.
* ALL, ANY, and MULTIEXPR require the combining operators to deliver boolean
* results. These are reduced to one result per row using OR or AND semantics
* depending on the "useor" flag. ALL and ANY combine the per-row results
* using AND and OR semantics respectively.
*
* NOTE: lefthand and oper have varying meanings depending on where you look
* in the parse/plan pipeline:
* 1. gram.y delivers a list of the (untransformed) lefthand expressions in
@ -348,12 +366,13 @@ typedef struct Aggref
* representation 2 appears in a "bare" SubLink, while representation 3 is
* found in SubLinks that are children of SubPlan nodes.
*
* In an EXISTS SubLink, both lefthand and oper are unused and are always NIL.
* In EXISTS and EXPR SubLinks, both lefthand and oper are unused and are
* always NIL. useor is not significant either for these sublink types.
* ----------------
*/
typedef enum SubLinkType
{
EXISTS_SUBLINK, ALL_SUBLINK, ANY_SUBLINK, EXPR_SUBLINK
EXISTS_SUBLINK, ALL_SUBLINK, ANY_SUBLINK, MULTIEXPR_SUBLINK, EXPR_SUBLINK
} SubLinkType;