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Cache fmgr lookup data for index's getnext() function in IndexScanDesc,

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so that the fmgr lookup only has to happen once per index scan and not
once per tuple.  Seems to save 5% or so of CPU time for an indexscan.
This commit is contained in:
Tom Lane 2000-03-14 23:52:01 +00:00
parent 6456810078
commit 34235a295b
3 changed files with 21 additions and 6 deletions
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5
src/backend/access/index/genam.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/index/genam.c,v 1.23 2000/01/26 05:55:57 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/access/index/genam.c,v 1.24 2000/03/14 23:52:01 tgl Exp $
*
* NOTES
* many of the old access method routines have been turned into
@ -114,6 +114,9 @@ RelationGetIndexScan(Relation relation,
ItemPointerSetInvalid(&scan->currentMarkData);
ItemPointerSetInvalid(&scan->nextMarkData);
/* mark cached function lookup data invalid; it will be set on first use */
scan->fn_getnext.fn_oid = InvalidOid;
if (numberOfKeys > 0)
scan->keyData = (ScanKey) palloc(sizeof(ScanKeyData) * numberOfKeys);
else

19
src/backend/access/index/indexam.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/index/indexam.c,v 1.40 2000/01/26 05:55:57 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/access/index/indexam.c,v 1.41 2000/03/14 23:52:01 tgl Exp $
*
* INTERFACE ROUTINES
* index_open - open an index relation by relationId
@ -329,17 +329,28 @@ RetrieveIndexResult
index_getnext(IndexScanDesc scan,
ScanDirection direction)
{
RegProcedure procedure;
RetrieveIndexResult result;
SCAN_CHECKS;
GET_SCAN_PROCEDURE(getnext, amgettuple);
/* ----------------
* Look up the access procedure only once per scan.
* ----------------
*/
if (scan->fn_getnext.fn_oid == InvalidOid)
{
RegProcedure procedure;
GET_SCAN_PROCEDURE(getnext, amgettuple);
fmgr_info(procedure, &scan->fn_getnext);
}
/* ----------------
* have the am's gettuple proc do all the work.
* ----------------
*/
result = (RetrieveIndexResult) fmgr(procedure, scan, direction);
result = (RetrieveIndexResult)
(*fmgr_faddr(&scan->fn_getnext)) (scan, direction);
return result;
}

3
src/include/access/relscan.h
View File

@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: relscan.h,v 1.18 2000/01/26 05:57:51 momjian Exp $
* $Id: relscan.h,v 1.19 2000/03/14 23:52:00 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -54,6 +54,7 @@ typedef struct IndexScanDescData
bool scanFromEnd; /* restart scan at end? */
uint16 numberOfKeys; /* number of key attributes */
ScanKey keyData; /* key descriptor */
FmgrInfo fn_getnext; /* cached lookup info for am's getnext fn */
} IndexScanDescData;
typedef IndexScanDescData *IndexScanDesc;