Modify RelationGetBufferForTuple() so that we only do lseek and lock

when we need to move to a new page; as long as we can insert the new
tuple on the same page as before, we only need LockBuffer and not the
expensive stuff.  Also, twiddle bufmgr interfaces to avoid redundant
lseeks in RelationGetBufferForTuple and BufferAlloc.  Successive inserts
now require one lseek per page added, rather than one per tuple with
several additional ones at each page boundary as happened before.
Lock contention when multiple backends are inserting in same table
is also greatly reduced.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/include/storage/bufmgr.h b/src/include/storage/bufmgr.h
index fc76f9fe4c5..d45c8888c1d 100644
--- a/src/include/storage/bufmgr.h
+++ b/src/include/storage/bufmgr.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: bufmgr.h,v 1.50 2001/03/22 04:01:05 momjian Exp $
+ * $Id: bufmgr.h,v 1.51 2001/05/12 19:58:28 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -164,7 +164,7 @@ extern Buffer ReadBuffer(Relation reln, BlockNumber blockNum);
 extern int	WriteBuffer(Buffer buffer);
 extern int	WriteNoReleaseBuffer(Buffer buffer);
 extern Buffer ReleaseAndReadBuffer(Buffer buffer, Relation relation,
-					 BlockNumber blockNum);
+								   BlockNumber blockNum, bool isExtend);
 extern int	FlushBuffer(Buffer buffer, bool sync, bool release);
 
 extern void InitBufferPool(void);