Some further performance tweaks for planning large inheritance trees that

are mostly excluded by constraints: do the CE test a bit earlier to save
some adjust_appendrel_attrs() work on excluded children, and arrange to
use array indexing rather than rt_fetch() to fetch RTEs in the main body
of the planner.  The latter is something I'd wanted to do for awhile anyway,
but seeing list_nth_cell() as 35% of the runtime gets one's attention.

1 files changed, 6 insertions, 6 deletions

diff --git a/src/backend/optimizer/util/relnode.c b/src/backend/optimizer/util/relnode.c
index 6dfd2f61149..56f8f3493c2 100644
--- a/src/backend/optimizer/util/relnode.c
+++ b/src/backend/optimizer/util/relnode.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/util/relnode.c,v 1.86 2007/02/22 22:00:25 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/util/relnode.c,v 1.87 2007/04/21 21:01:45 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -56,15 +56,15 @@ build_simple_rel(PlannerInfo *root, int relid, RelOptKind reloptkind)
 	RelOptInfo *rel;
 	RangeTblEntry *rte;
 
-	/* Fetch RTE for relation */
-	Assert(relid > 0 && relid <= list_length(root->parse->rtable));
-	rte = rt_fetch(relid, root->parse->rtable);
-
 	/* Rel should not exist already */
-	Assert(relid < root->simple_rel_array_size);
+	Assert(relid > 0 && relid < root->simple_rel_array_size);
 	if (root->simple_rel_array[relid] != NULL)
 		elog(ERROR, "rel %d already exists", relid);
 
+	/* Fetch RTE for relation */
+	rte = root->simple_rte_array[relid];
+	Assert(rte != NULL);
+
 	rel = makeNode(RelOptInfo);
 	rel->reloptkind = reloptkind;
 	rel->relids = bms_make_singleton(relid);