From 80dab5bd69cd5bcd064a7da9f3d1b22eb770925a Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Fri, 24 Nov 2000 04:16:12 +0000
Subject: [PATCH] A catalog cache that never caches isn't much of a cache :-(.
Mea culpa. Thanks to Brian Hirt for pointing out the performance lossage.
---
src/backend/utils/cache/catcache.c | 28 +++++++++++++++-------------
src/include/utils/catcache.h | 4 ++--
2 files changed, 17 insertions(+), 15 deletions(-)
diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c
index 3d8e7d80ba8..3e1c428a532 100644
--- a/src/backend/utils/cache/catcache.c
+++ b/src/backend/utils/cache/catcache.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/utils/cache/catcache.c,v 1.72 2000/11/16 22:30:33 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/cache/catcache.c,v 1.73 2000/11/24 04:16:12 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -258,8 +258,8 @@ CatalogCacheInitializeCache(CatCache *cache)
&cache->cc_skey[i].sk_func);
cache->cc_skey[i].sk_nargs = cache->cc_skey[i].sk_func.fn_nargs;
- /* Initialize sk_attno suitably for index scans */
- cache->cc_skey[i].sk_attno = i+1;
+ /* Initialize sk_attno suitably for HeapKeyTest() and heap scans */
+ cache->cc_skey[i].sk_attno = cache->cc_key[i];
CACHE4_elog(DEBUG, "CatalogCacheInit %s %d %p",
cache->cc_relname,
@@ -664,8 +664,8 @@ InitCatCache(int id,
/* ----------------
* initialize the cache's relation information for the relation
- * corresponding to this cache and initialize some of the the new
- * cache's other internal fields.
+ * corresponding to this cache, and initialize some of the new
+ * cache's other internal fields. But don't open the relation yet.
* ----------------
*/
cp->cc_relname = relname;
@@ -885,10 +885,20 @@ SearchCatCache(CatCache *cache,
RetrieveIndexResult indexRes;
HeapTupleData tuple;
Buffer buffer;
+ int i;
CACHE2_elog(DEBUG, "SearchCatCache(%s): performing index scan",
cache->cc_relname);
+ /*
+ * For an index scan, sk_attno has to be set to the index attribute
+ * number(s), not the heap attribute numbers. We assume that the
+ * index corresponds exactly to the cache keys (or its first N
+ * keys do, anyway).
+ */
+ for (i = 0; i < cache->cc_nkeys; ++i)
+ cur_skey[i].sk_attno = i+1;
+
idesc = index_openr(cache->cc_indname);
isd = index_beginscan(idesc, false, cache->cc_nkeys, cur_skey);
tuple.t_datamcxt = CurrentMemoryContext;
@@ -915,18 +925,10 @@ SearchCatCache(CatCache *cache,
else
{
HeapScanDesc sd;
- int i;
CACHE2_elog(DEBUG, "SearchCatCache(%s): performing heap scan",
cache->cc_relname);
- /*
- * For a heap scan, sk_attno has to be set to the heap attribute
- * number(s), not the index attribute numbers.
- */
- for (i = 0; i < cache->cc_nkeys; ++i)
- cur_skey[i].sk_attno = cache->cc_key[i];
-
sd = heap_beginscan(relation, 0, SnapshotNow,
cache->cc_nkeys, cur_skey);
diff --git a/src/include/utils/catcache.h b/src/include/utils/catcache.h
index ed78284a478..70c988ca185 100644
--- a/src/include/utils/catcache.h
+++ b/src/include/utils/catcache.h
@@ -13,7 +13,7 @@
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: catcache.h,v 1.28 2000/11/16 22:30:49 tgl Exp $
+ * $Id: catcache.h,v 1.29 2000/11/24 04:16:11 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -70,7 +70,7 @@ typedef struct catcache
short cc_nkeys; /* number of keys (1..4) */
short cc_key[4]; /* AttrNumber of each key */
PGFunction cc_hashfunc[4]; /* hash function to use for each key */
- ScanKeyData cc_skey[4]; /* precomputed key info for indexscans */
+ ScanKeyData cc_skey[4]; /* precomputed key info for heap scans */
Dllist cc_lrulist; /* overall LRU list, most recent first */
Dllist cc_cache[NCCBUCK]; /* hash buckets */
} CatCache;
--
GitLab