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-rw-r--r--src/backend/optimizer/plan/setrefs.c74
1 files changed, 52 insertions, 22 deletions
diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c
index 167901acdf0..2f48821ece6 100644
--- a/src/backend/optimizer/plan/setrefs.c
+++ b/src/backend/optimizer/plan/setrefs.c
@@ -9,25 +9,29 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/setrefs.c,v 1.73 2001/11/05 17:46:26 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/setrefs.c,v 1.74 2002/03/12 00:51:48 tgl Exp $
*
*-------------------------------------------------------------------------
*/
-#include <sys/types.h>
-
#include "postgres.h"
+#include <sys/types.h>
+
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/clauses.h"
#include "optimizer/planmain.h"
#include "optimizer/tlist.h"
+#include "optimizer/var.h"
+
typedef struct
{
+ Query *root;
List *outer_tlist;
List *inner_tlist;
Index acceptable_rel;
+ Index join_rti;
} join_references_context;
typedef struct
@@ -38,7 +42,7 @@ typedef struct
} replace_vars_with_subplan_refs_context;
static void fix_expr_references(Plan *plan, Node *node);
-static void set_join_references(Join *join);
+static void set_join_references(Query *root, Join *join);
static void set_uppernode_references(Plan *plan, Index subvarno);
static Node *join_references_mutator(Node *node,
join_references_context *context);
@@ -71,7 +75,7 @@ static bool fix_opids_walker(Node *node, void *context);
* Returns nothing of interest, but modifies internal fields of nodes.
*/
void
-set_plan_references(Plan *plan)
+set_plan_references(Query *root, Plan *plan)
{
List *pl;
@@ -115,16 +119,16 @@ set_plan_references(Plan *plan)
fix_expr_references(plan, (Node *) plan->targetlist);
fix_expr_references(plan, (Node *) plan->qual);
/* Recurse into subplan too */
- set_plan_references(((SubqueryScan *) plan)->subplan);
+ set_plan_references(root, ((SubqueryScan *) plan)->subplan);
break;
case T_NestLoop:
- set_join_references((Join *) plan);
+ set_join_references(root, (Join *) plan);
fix_expr_references(plan, (Node *) plan->targetlist);
fix_expr_references(plan, (Node *) plan->qual);
fix_expr_references(plan, (Node *) ((Join *) plan)->joinqual);
break;
case T_MergeJoin:
- set_join_references((Join *) plan);
+ set_join_references(root, (Join *) plan);
fix_expr_references(plan, (Node *) plan->targetlist);
fix_expr_references(plan, (Node *) plan->qual);
fix_expr_references(plan, (Node *) ((Join *) plan)->joinqual);
@@ -132,7 +136,7 @@ set_plan_references(Plan *plan)
(Node *) ((MergeJoin *) plan)->mergeclauses);
break;
case T_HashJoin:
- set_join_references((Join *) plan);
+ set_join_references(root, (Join *) plan);
fix_expr_references(plan, (Node *) plan->targetlist);
fix_expr_references(plan, (Node *) plan->qual);
fix_expr_references(plan, (Node *) ((Join *) plan)->joinqual);
@@ -186,7 +190,7 @@ set_plan_references(Plan *plan)
* recurse into subplans.
*/
foreach(pl, ((Append *) plan)->appendplans)
- set_plan_references((Plan *) lfirst(pl));
+ set_plan_references(root, (Plan *) lfirst(pl));
break;
default:
elog(ERROR, "set_plan_references: unknown plan type %d",
@@ -203,21 +207,21 @@ set_plan_references(Plan *plan)
* plan's var nodes against the already-modified nodes of the
* subplans.
*/
- set_plan_references(plan->lefttree);
- set_plan_references(plan->righttree);
+ set_plan_references(root, plan->lefttree);
+ set_plan_references(root, plan->righttree);
foreach(pl, plan->initPlan)
{
SubPlan *sp = (SubPlan *) lfirst(pl);
Assert(IsA(sp, SubPlan));
- set_plan_references(sp->plan);
+ set_plan_references(root, sp->plan);
}
foreach(pl, plan->subPlan)
{
SubPlan *sp = (SubPlan *) lfirst(pl);
Assert(IsA(sp, SubPlan));
- set_plan_references(sp->plan);
+ set_plan_references(root, sp->plan);
}
}
@@ -256,7 +260,7 @@ fix_expr_references(Plan *plan, Node *node)
* 'join' is a join plan node
*/
static void
-set_join_references(Join *join)
+set_join_references(Query *root, Join *join)
{
Plan *outer = join->plan.lefttree;
Plan *inner = join->plan.righttree;
@@ -264,9 +268,11 @@ set_join_references(Join *join)
List *inner_tlist = ((inner == NULL) ? NIL : inner->targetlist);
join->plan.targetlist = join_references(join->plan.targetlist,
+ root,
outer_tlist,
inner_tlist,
- (Index) 0);
+ (Index) 0,
+ join->joinrti);
}
/*
@@ -343,7 +349,8 @@ set_uppernode_references(Plan *plan, Index subvarno)
* Creates a new set of targetlist entries or join qual clauses by
* changing the varno/varattno values of variables in the clauses
* to reference target list values from the outer and inner join
- * relation target lists.
+ * relation target lists. Also, any join alias variables in the
+ * clauses are expanded into references to their component variables.
*
* This is used in two different scenarios: a normal join clause, where
* all the Vars in the clause *must* be replaced by OUTER or INNER references;
@@ -360,21 +367,27 @@ set_uppernode_references(Plan *plan, Index subvarno)
* 'inner_tlist' is the target list of the inner join relation, or NIL
* 'acceptable_rel' is either zero or the rangetable index of a relation
* whose Vars may appear in the clause without provoking an error.
+ * 'join_rti' is either zero or the join RTE index of join alias variables
+ * that should be expanded.
*
* Returns the new expression tree. The original clause structure is
* not modified.
*/
List *
join_references(List *clauses,
+ Query *root,
List *outer_tlist,
List *inner_tlist,
- Index acceptable_rel)
+ Index acceptable_rel,
+ Index join_rti)
{
join_references_context context;
+ context.root = root;
context.outer_tlist = outer_tlist;
context.inner_tlist = inner_tlist;
context.acceptable_rel = acceptable_rel;
+ context.join_rti = join_rti;
return (List *) join_references_mutator((Node *) clauses, &context);
}
@@ -387,12 +400,14 @@ join_references_mutator(Node *node,
if (IsA(node, Var))
{
Var *var = (Var *) node;
- Var *newvar = (Var *) copyObject(var);
Resdom *resdom;
+ /* First look for the var in the input tlists */
resdom = tlist_member((Node *) var, context->outer_tlist);
if (resdom)
{
+ Var *newvar = (Var *) copyObject(var);
+
newvar->varno = OUTER;
newvar->varattno = resdom->resno;
return (Node *) newvar;
@@ -400,18 +415,33 @@ join_references_mutator(Node *node,
resdom = tlist_member((Node *) var, context->inner_tlist);
if (resdom)
{
+ Var *newvar = (Var *) copyObject(var);
+
newvar->varno = INNER;
newvar->varattno = resdom->resno;
return (Node *) newvar;
}
+ /* Perhaps it's a join alias that can be resolved to input vars? */
+ if (var->varno == context->join_rti)
+ {
+ Node *newnode;
+
+ newnode = flatten_join_alias_vars((Node *) var,
+ context->root,
+ context->join_rti);
+ /* Must now resolve the input vars... */
+ newnode = join_references_mutator(newnode, context);
+ return newnode;
+ }
+
/*
- * Var not in either tlist --- either raise an error, or return
- * the Var unmodified.
+ * No referent found for Var --- either raise an error, or return
+ * the Var unmodified if it's for acceptable_rel.
*/
if (var->varno != context->acceptable_rel)
elog(ERROR, "join_references: variable not in subplan target lists");
- return (Node *) newvar;
+ return (Node *) copyObject(var);
}
return expression_tree_mutator(node,
join_references_mutator,
generated by cgit v1.2.3 (git 2.46.0) at 2025-08-10 13:30:44 +0000