From 57b82bf324285464783796e5614d5f9aadd0817f Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Mon, 30 Apr 2007 00:16:43 +0000
Subject: [PATCH] Marginal performance hack: use a dedicated routine instead of
copyObject to copy nodes that are known to be Vars during plan reference
adjustment. Saves useless memzero operation as well as the big switch in
copyObject.
---
src/backend/optimizer/plan/setrefs.c | 24 ++++++++++++++++++++----
1 file changed, 20 insertions(+), 4 deletions(-)
diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c
index 0739142403e..90a49983ac6 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 1.134 2007/04/06 22:57:20 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/optimizer/plan/setrefs.c,v 1.135 2007/04/30 00:16:43 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -565,6 +565,22 @@ trivial_subqueryscan(SubqueryScan *plan)
return true;
}
+/*
+ * copyVar
+ * Copy a Var node.
+ *
+ * fix_scan_expr and friends do this enough times that it's worth having
+ * a bespoke routine instead of using the generic copyObject() function.
+ */
+static inline Var *
+copyVar(Var *var)
+{
+ Var *newvar = (Var *) palloc(sizeof(Var));
+
+ *newvar = *var;
+ return newvar;
+}
+
/*
* fix_scan_expr
* Do set_plan_references processing on a scan-level expression
@@ -588,7 +604,7 @@ fix_scan_expr_mutator(Node *node, fix_scan_expr_context *context)
return NULL;
if (IsA(node, Var))
{
- Var *var = (Var *) copyObject(node);
+ Var *var = copyVar((Var *) node);
Assert(var->varlevelsup == 0);
/*
@@ -1091,7 +1107,7 @@ search_indexed_tlist_for_var(Var *var, indexed_tlist *itlist,
if (vinfo->varno == varno && vinfo->varattno == varattno)
{
/* Found a match */
- Var *newvar = (Var *) copyObject(var);
+ Var *newvar = copyVar(var);
newvar->varno = newvarno;
newvar->varattno = vinfo->resno;
@@ -1213,7 +1229,7 @@ fix_join_expr_mutator(Node *node, fix_join_expr_context *context)
/* If it's for acceptable_rel, adjust and return it */
if (var->varno == context->acceptable_rel)
{
- var = (Var *) copyObject(var);
+ var = copyVar(var);
var->varno += context->rtoffset;
var->varnoold += context->rtoffset;
return (Node *) var;
--
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