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Micro-optimization of markpos() and restrpos() in btree and hash indexes.

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Rather than using ReadBuffer() to increment the reference count on an
already-pinned buffer, we should use IncrBufferRefCount() as it is
faster and does not require acquiring the BufMgrLock.
This commit is contained in:
Neil Conway 2004-11-17 03:13:38 +00:00
parent a51e54cf5b
commit 5d1dd2bc55
2 changed files with 10 additions and 12 deletions
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12
src/backend/access/hash/hash.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/access/hash/hash.c,v 1.74 2004/11/11 00:32:40 neilc Exp $
* $PostgreSQL: pgsql/src/backend/access/hash/hash.c,v 1.75 2004/11/17 03:13:37 neilc Exp $
*
* NOTES
* This file contains only the public interface routines.
@ -397,9 +397,8 @@ hashmarkpos(PG_FUNCTION_ARGS)
/* bump pin count on currentItemData and copy to currentMarkData */
if (ItemPointerIsValid(&(scan->currentItemData)))
{
so->hashso_mrkbuf = _hash_getbuf(rel,
BufferGetBlockNumber(so->hashso_curbuf),
HASH_NOLOCK);
IncrBufferRefCount(so->hashso_curbuf);
so->hashso_mrkbuf = so->hashso_curbuf;
scan->currentMarkData = scan->currentItemData;
}
@ -425,9 +424,8 @@ hashrestrpos(PG_FUNCTION_ARGS)
/* bump pin count on currentMarkData and copy to currentItemData */
if (ItemPointerIsValid(&(scan->currentMarkData)))
{
so->hashso_curbuf = _hash_getbuf(rel,
BufferGetBlockNumber(so->hashso_mrkbuf),
HASH_NOLOCK);
IncrBufferRefCount(so->hashso_mrkbuf);
so->hashso_curbuf = so->hashso_mrkbuf;
scan->currentItemData = scan->currentMarkData;
}

10
src/backend/access/nbtree/nbtree.c
View File

@ -12,7 +12,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/access/nbtree/nbtree.c,v 1.121 2004/11/11 00:32:50 neilc Exp $
* $PostgreSQL: pgsql/src/backend/access/nbtree/nbtree.c,v 1.122 2004/11/17 03:13:38 neilc Exp $
*
*-------------------------------------------------------------------------
*/
@ -477,8 +477,8 @@ btmarkpos(PG_FUNCTION_ARGS)
/* bump pin on current buffer for assignment to mark buffer */
if (ItemPointerIsValid(&(scan->currentItemData)))
{
so->btso_mrkbuf = ReadBuffer(scan->indexRelation,
BufferGetBlockNumber(so->btso_curbuf));
IncrBufferRefCount(so->btso_curbuf);
so->btso_mrkbuf = so->btso_curbuf;
scan->currentMarkData = scan->currentItemData;
so->mrkHeapIptr = so->curHeapIptr;
}
@ -509,8 +509,8 @@ btrestrpos(PG_FUNCTION_ARGS)
/* bump pin on marked buffer */
if (ItemPointerIsValid(&(scan->currentMarkData)))
{
so->btso_curbuf = ReadBuffer(scan->indexRelation,
BufferGetBlockNumber(so->btso_mrkbuf));
IncrBufferRefCount(so->btso_mrkbuf);
so->btso_curbuf = so->btso_mrkbuf;
scan->currentItemData = scan->currentMarkData;
so->curHeapIptr = so->mrkHeapIptr;
}