Adjust nodeBitmapIndexscan to keep the target index opened from plan

startup to end, rather than re-opening it in each MultiExecBitmapIndexScan
call.  I had foolishly thought that opening/closing wouldn't be much
more expensive than a rescan call, but that was sheer brain fade.

This seems to fix about half of the performance lossage reported by
Sergey Koposov.  I'm still not sure where the other half went.

1 files changed, 5 insertions, 1 deletions

diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 1280aff0ca0..2d74d25a361 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/execnodes.h,v 1.130 2005/04/28 21:47:17 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/execnodes.h,v 1.131 2005/05/05 03:37:23 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -897,6 +897,8 @@ typedef struct IndexScanState
  *						   that will be evaluated at runtime
  *		RuntimeContext	   expr context for evaling runtime Skeys
  *		RuntimeKeysReady   true if runtime Skeys have been computed
+ *		RelationDesc	   index relation descriptor
+ *		ScanDesc		   index scan descriptor
  * ----------------
  */
 typedef struct BitmapIndexScanState
@@ -908,6 +910,8 @@ typedef struct BitmapIndexScanState
 	ExprState **biss_RuntimeKeyInfo;
 	ExprContext *biss_RuntimeContext;
 	bool		biss_RuntimeKeysReady;
+	Relation	biss_RelationDesc;
+	IndexScanDesc biss_ScanDesc;
 } BitmapIndexScanState;
 
 /* ----------------