Turn the rangetable used by the executor into a flat list, and avoid storing

useless substructure for its RangeTblEntry nodes.  (I chose to keep using the
same struct node type and just zero out the link fields for unneeded info,
rather than making a separate ExecRangeTblEntry type --- it seemed too
fragile to have two different rangetable representations.)

Along the way, put subplans into a list in the toplevel PlannedStmt node,
and have SubPlan nodes refer to them by list index instead of direct pointers.
Vadim wanted to do that years ago, but I never understood what he was on about
until now.  It makes things a *whole* lot more robust, because we can stop
worrying about duplicate processing of subplans during expression tree
traversals.  That's been a constant source of bugs, and it's finally gone.

There are some consequent simplifications yet to be made, like not using
a separate EState for subplans in the executor, but I'll tackle that later.

1 files changed, 2 insertions, 4 deletions

diff --git a/src/backend/executor/execUtils.c b/src/backend/executor/execUtils.c
index d9957573883..d188a38489d 100644
--- a/src/backend/executor/execUtils.c
+++ b/src/backend/executor/execUtils.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/execUtils.c,v 1.145 2007/02/20 17:32:14 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/execUtils.c,v 1.146 2007/02/22 22:00:22 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -847,7 +847,6 @@ ExecRelationIsTargetRelation(EState *estate, Index scanrelid)
 Relation
 ExecOpenScanRelation(EState *estate, Index scanrelid)
 {
-	RangeTblEntry *rtentry;
 	Oid			reloid;
 	LOCKMODE	lockmode;
 	ResultRelInfo *resultRelInfos;
@@ -885,8 +884,7 @@ ExecOpenScanRelation(EState *estate, Index scanrelid)
 	}
 
 	/* OK, open the relation and acquire lock as needed */
-	rtentry = rt_fetch(scanrelid, estate->es_range_table);
-	reloid = rtentry->relid;
+	reloid = getrelid(scanrelid, estate->es_range_table);
 
 	return heap_open(reloid, lockmode);
 }