From 8db05ba411ecd3ce2cb0cb7c78fec87658e1a4ab Mon Sep 17 00:00:00 2001
From: Tom Lane
Date: Tue, 7 Mar 2006 19:06:50 +0000
Subject: Repair old performance bug in tuplesort.c/logtape.c.  In the case
 where we are doing the final merge pass on-the-fly, and not writing the data
 back onto a 'tape', the number of free blocks in the tape set will become
 large, leading to a lot of time wasted in ltsReleaseBlock().  There is really
 no need to track the free blocks anymore in this state, so add a simple
 shutoff switch.  Per report from Stefan Kaltenbrunner.

---
 src/include/utils/logtape.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 'src/include')

diff --git a/src/include/utils/logtape.h b/src/include/utils/logtape.h
index 3791f03e9e3..7cd3db37774 100644
--- a/src/include/utils/logtape.h
+++ b/src/include/utils/logtape.h
@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/utils/logtape.h,v 1.14 2006/03/05 15:59:07 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/utils/logtape.h,v 1.15 2006/03/07 19:06:50 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -26,6 +26,7 @@ typedef struct LogicalTapeSet LogicalTapeSet;
 
 extern LogicalTapeSet *LogicalTapeSetCreate(int ntapes);
 extern void LogicalTapeSetClose(LogicalTapeSet *lts);
+extern void LogicalTapeSetForgetFreeSpace(LogicalTapeSet *lts);
 extern size_t LogicalTapeRead(LogicalTapeSet *lts, int tapenum,
 				void *ptr, size_t size);
 extern void LogicalTapeWrite(LogicalTapeSet *lts, int tapenum,
-- 
cgit v1.2.3