summaryrefslogtreecommitdiff
path: root/src/backend/optimizer/plan/setrefs.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/backend/optimizer/plan/setrefs.c')
-rw-r--r--src/backend/optimizer/plan/setrefs.c82
1 files changed, 75 insertions, 7 deletions
diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c
index 6d7ec283b34..9bec109f6f5 100644
--- a/src/backend/optimizer/plan/setrefs.c
+++ b/src/backend/optimizer/plan/setrefs.c
@@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/optimizer/plan/setrefs.c,v 1.145 2008/10/04 21:56:53 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/optimizer/plan/setrefs.c,v 1.146 2008/10/21 20:42:53 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -38,7 +38,8 @@ typedef struct
{
List *tlist; /* underlying target list */
int num_vars; /* number of plain Var tlist entries */
- bool has_non_vars; /* are there non-plain-Var entries? */
+ bool has_ph_vars; /* are there PlaceHolderVar entries? */
+ bool has_non_vars; /* are there other entries? */
/* array of num_vars entries: */
tlist_vinfo vars[1]; /* VARIABLE LENGTH ARRAY */
} indexed_tlist; /* VARIABLE LENGTH STRUCT */
@@ -741,15 +742,16 @@ fix_scan_expr(PlannerGlobal *glob, Node *node, int rtoffset)
context.glob = glob;
context.rtoffset = rtoffset;
- if (rtoffset != 0)
+ if (rtoffset != 0 || glob->lastPHId != 0)
{
return fix_scan_expr_mutator(node, &context);
}
else
{
/*
- * If rtoffset == 0, we don't need to change any Vars, which makes
- * it OK to just scribble on the input node tree instead of copying
+ * If rtoffset == 0, we don't need to change any Vars, and if there
+ * are no placeholders anywhere we won't need to remove them. Then
+ * it's OK to just scribble on the input node tree instead of copying
* (since the only change, filling in any unset opfuncid fields,
* is harmless). This saves just enough cycles to be noticeable on
* trivial queries.
@@ -790,6 +792,13 @@ fix_scan_expr_mutator(Node *node, fix_scan_expr_context *context)
cexpr->cvarno += context->rtoffset;
return (Node *) cexpr;
}
+ if (IsA(node, PlaceHolderVar))
+ {
+ /* At scan level, we should always just evaluate the contained expr */
+ PlaceHolderVar *phv = (PlaceHolderVar *) node;
+
+ return fix_scan_expr_mutator((Node *) phv->phexpr, context);
+ }
fix_expr_common(context->glob, node);
return expression_tree_mutator(node, fix_scan_expr_mutator,
(void *) context);
@@ -800,6 +809,7 @@ fix_scan_expr_walker(Node *node, fix_scan_expr_context *context)
{
if (node == NULL)
return false;
+ Assert(!IsA(node, PlaceHolderVar));
fix_expr_common(context->glob, node);
return expression_tree_walker(node, fix_scan_expr_walker,
(void *) context);
@@ -1199,6 +1209,7 @@ build_tlist_index(List *tlist)
list_length(tlist) * sizeof(tlist_vinfo));
itlist->tlist = tlist;
+ itlist->has_ph_vars = false;
itlist->has_non_vars = false;
/* Find the Vars and fill in the index array */
@@ -1216,6 +1227,8 @@ build_tlist_index(List *tlist)
vinfo->resno = tle->resno;
vinfo++;
}
+ else if (tle->expr && IsA(tle->expr, PlaceHolderVar))
+ itlist->has_ph_vars = true;
else
itlist->has_non_vars = true;
}
@@ -1229,7 +1242,9 @@ build_tlist_index(List *tlist)
* build_tlist_index_other_vars --- build a restricted tlist index
*
* This is like build_tlist_index, but we only index tlist entries that
- * are Vars and belong to some rel other than the one specified.
+ * are Vars belonging to some rel other than the one specified. We will set
+ * has_ph_vars (allowing PlaceHolderVars to be matched), but not has_non_vars
+ * (so nothing other than Vars and PlaceHolderVars can be matched).
*/
static indexed_tlist *
build_tlist_index_other_vars(List *tlist, Index ignore_rel)
@@ -1244,6 +1259,7 @@ build_tlist_index_other_vars(List *tlist, Index ignore_rel)
list_length(tlist) * sizeof(tlist_vinfo));
itlist->tlist = tlist;
+ itlist->has_ph_vars = false;
itlist->has_non_vars = false;
/* Find the desired Vars and fill in the index array */
@@ -1264,6 +1280,8 @@ build_tlist_index_other_vars(List *tlist, Index ignore_rel)
vinfo++;
}
}
+ else if (tle->expr && IsA(tle->expr, PlaceHolderVar))
+ itlist->has_ph_vars = true;
}
itlist->num_vars = (vinfo - itlist->vars);
@@ -1314,7 +1332,8 @@ search_indexed_tlist_for_var(Var *var, indexed_tlist *itlist,
* If a match is found, return a Var constructed to reference the tlist item.
* If no match, return NULL.
*
- * NOTE: it is a waste of time to call this if !itlist->has_non_vars
+ * NOTE: it is a waste of time to call this unless itlist->has_ph_vars or
+ * itlist->has_non_vars
*/
static Var *
search_indexed_tlist_for_non_var(Node *node,
@@ -1429,6 +1448,31 @@ fix_join_expr_mutator(Node *node, fix_join_expr_context *context)
/* No referent found for Var */
elog(ERROR, "variable not found in subplan target lists");
}
+ if (IsA(node, PlaceHolderVar))
+ {
+ PlaceHolderVar *phv = (PlaceHolderVar *) node;
+
+ /* See if the PlaceHolderVar has bubbled up from a lower plan node */
+ if (context->outer_itlist->has_ph_vars)
+ {
+ newvar = search_indexed_tlist_for_non_var((Node *) phv,
+ context->outer_itlist,
+ OUTER);
+ if (newvar)
+ return (Node *) newvar;
+ }
+ if (context->inner_itlist && context->inner_itlist->has_ph_vars)
+ {
+ newvar = search_indexed_tlist_for_non_var((Node *) phv,
+ context->inner_itlist,
+ INNER);
+ if (newvar)
+ return (Node *) newvar;
+ }
+
+ /* If not supplied by input plans, evaluate the contained expr */
+ return fix_join_expr_mutator((Node *) phv->phexpr, context);
+ }
/* Try matching more complex expressions too, if tlists have any */
if (context->outer_itlist->has_non_vars)
{
@@ -1512,6 +1556,22 @@ fix_upper_expr_mutator(Node *node, fix_upper_expr_context *context)
elog(ERROR, "variable not found in subplan target list");
return (Node *) newvar;
}
+ if (IsA(node, PlaceHolderVar))
+ {
+ PlaceHolderVar *phv = (PlaceHolderVar *) node;
+
+ /* See if the PlaceHolderVar has bubbled up from a lower plan node */
+ if (context->subplan_itlist->has_ph_vars)
+ {
+ newvar = search_indexed_tlist_for_non_var((Node *) phv,
+ context->subplan_itlist,
+ OUTER);
+ if (newvar)
+ return (Node *) newvar;
+ }
+ /* If not supplied by input plan, evaluate the contained expr */
+ return fix_upper_expr_mutator((Node *) phv->phexpr, context);
+ }
/* Try matching more complex expressions too, if tlist has any */
if (context->subplan_itlist->has_non_vars)
{
@@ -1564,6 +1624,13 @@ set_returning_clause_references(PlannerGlobal *glob,
* top plan's targetlist for Vars of non-result relations, and use
* fix_join_expr to convert RETURNING Vars into references to those tlist
* entries, while leaving result-rel Vars as-is.
+ *
+ * PlaceHolderVars will also be sought in the targetlist, but no
+ * more-complex expressions will be. Note that it is not possible for
+ * a PlaceHolderVar to refer to the result relation, since the result
+ * is never below an outer join. If that case could happen, we'd have
+ * to be prepared to pick apart the PlaceHolderVar and evaluate its
+ * contained expression instead.
*/
itlist = build_tlist_index_other_vars(topplan->targetlist, resultRelation);
@@ -1721,6 +1788,7 @@ extract_query_dependencies_walker(Node *node, PlannerGlobal *context)
{
if (node == NULL)
return false;
+ Assert(!IsA(node, PlaceHolderVar));
/* Extract function dependencies and check for regclass Consts */
fix_expr_common(context, node);
if (IsA(node, Query))
generated by cgit v1.2.3 (git 2.46.0) at 2025-08-28 09:21:14 +0000