database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-10-25 13:17:41 +03:00
Code Activity

Arrange to cache fmgr lookup information for an index's access method

Browse Source 
routines in the index's relcache entry, instead of doing a fresh fmgr_info
on every index access.  We were already doing this for the index's opclass
support functions; not sure why we didn't think to do it for the AM
functions too.  This supersedes the former method of caching (only)
amgettuple in indexscan scan descriptors; it's an improvement because the
function lookup can be amortized across multiple statements instead of
being repeated for each statement.  Even though lookup for builtin
functions is pretty cheap, this seems to drop a percent or two off some
simple benchmarks.
This commit is contained in:
Tom Lane
2005-05-27 23:31:21 +00:00
parent dd67cf365a
commit 32e8fc4a28
6 changed files with 118 additions and 96 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
src/include/access/genam.h
View File

@@ -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/access/genam.h,v 1.50 2005/04/14 20:03:27 tgl Exp $
* $PostgreSQL: pgsql/src/include/access/genam.h,v 1.51 2005/05/27 23:31:21 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -104,7 +104,7 @@ extern IndexBulkDeleteResult *index_vacuum_cleanup(Relation indexRelation,
extern RegProcedure index_cost_estimator(Relation indexRelation);
extern RegProcedure index_getprocid(Relation irel, AttrNumber attnum,
uint16 procnum);
extern struct FmgrInfo *index_getprocinfo(Relation irel, AttrNumber attnum,
extern FmgrInfo *index_getprocinfo(Relation irel, AttrNumber attnum,
uint16 procnum);
/*

11
src/include/access/relscan.h
View File

@@ -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/access/relscan.h,v 1.38 2005/03/27 23:53:04 tgl Exp $
* $PostgreSQL: pgsql/src/include/access/relscan.h,v 1.39 2005/05/27 23:31:21 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -40,9 +40,8 @@ typedef HeapScanDescData *HeapScanDesc;
/*
* We use the same IndexScanDescData structure for both amgettuple-based
* and amgetmulti-based index scans. Which one is being used can be told
* by looking at fn_getnext and fn_getmulti, only one of which will be
* initialized. Some fields are only relevant in amgettuple-based scans.
* and amgetmulti-based index scans. Some fields are only relevant in
* amgettuple-based scans.
*/
typedef struct IndexScanDescData
{
@@ -52,6 +51,7 @@ typedef struct IndexScanDescData
Snapshot xs_snapshot; /* snapshot to see */
int numberOfKeys; /* number of scan keys */
ScanKey keyData; /* array of scan key descriptors */
bool is_multiscan; /* TRUE = using amgetmulti */
/* signaling to index AM about killing index tuples */
bool kill_prior_tuple; /* last-returned tuple is dead */
@@ -75,9 +75,6 @@ typedef struct IndexScanDescData
Buffer xs_cbuf; /* current heap buffer in scan, if any */
/* NB: if xs_cbuf is not InvalidBuffer, we hold a pin on that buffer */
FmgrInfo fn_getnext; /* cached lookup info for AM's getnext fn */
FmgrInfo fn_getmulti; /* cached lookup info for AM's getmulti fn */
/*
* If keys_are_unique and got_tuple are both true, we stop calling the
* index AM; it is then necessary for index_getnext to keep track of