Cache eval cost of qualification expressions in RestrictInfo nodes to

avoid repeated evaluations in cost_qual_eval().  This turns out to save
a useful fraction of planning time.  No change to external representation
of RestrictInfo --- although that node type doesn't appear in stored
rules anyway.

3 files changed, 11 insertions, 3 deletions

diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 1e03e044182..3e4a6d91dd1 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.133 2000/11/24 20:16:39 petere Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.134 2000/12/12 23:33:32 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1418,6 +1418,7 @@ _copyRestrictInfo(RestrictInfo *from)
 	 * ----------------
 	 */
 	Node_Copy(from, newnode, clause);
+	newnode->eval_cost = from->eval_cost;
 	newnode->ispusheddown = from->ispusheddown;
 	Node_Copy(from, newnode, subclauseindices);
 	newnode->mergejoinoperator = from->mergejoinoperator;
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index 51dbd24976c..2f6a93b95ba 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -20,7 +20,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.83 2000/11/24 20:16:39 petere Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.84 2000/12/12 23:33:33 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -514,6 +514,10 @@ _equalRestrictInfo(RestrictInfo *a, RestrictInfo *b)
 {
 	if (!equal(a->clause, b->clause))
 		return false;
+	/*
+	 * ignore eval_cost, since it may not be set yet, and should be
+	 * derivable from the clause anyway
+	 */
 	if (a->ispusheddown != b->ispusheddown)
 		return false;
 	if (!equal(a->subclauseindices, b->subclauseindices))
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index 6a6dce48bfb..d8aa2a5d2dc 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.100 2000/11/12 00:36:57 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/readfuncs.c,v 1.101 2000/12/12 23:33:33 tgl Exp $
  *
  * NOTES
  *	  Most of the read functions for plan nodes are tested. (In fact, they
@@ -1846,6 +1846,9 @@ _readRestrictInfo(void)
 	token = lsptok(NULL, &length);		/* now read it */
 	local_node->hashjoinoperator = (Oid) atol(token);
 
+	/* eval_cost is not part of saved representation; compute on first use */
+	local_node->eval_cost = -1;
+
 	return local_node;
 }