diff options
Diffstat (limited to 'src/backend/utils/cache/catcache.c')
| -rw-r--r-- | src/backend/utils/cache/catcache.c | 119 |
1 files changed, 77 insertions, 42 deletions
diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c index e5a1684041c..96e8288916a 100644 --- a/src/backend/utils/cache/catcache.c +++ b/src/backend/utils/cache/catcache.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/utils/cache/catcache.c,v 1.53 1999/11/21 01:58:22 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/utils/cache/catcache.c,v 1.54 1999/11/22 17:56:31 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -15,6 +15,7 @@ #include "access/genam.h" #include "access/heapam.h" #include "access/valid.h" +#include "catalog/pg_operator.h" #include "catalog/pg_type.h" #include "catalog/catname.h" #include "catalog/indexing.h" @@ -711,7 +712,6 @@ InitSysCache(char *relname, * ---------------- */ { - /* * We can only do this optimization because the number of hash * buckets never changes. Without it, we call malloc() too much. @@ -811,9 +811,10 @@ InitSysCache(char *relname, /* -------------------------------- * SearchSelfReferences * - * This call searches a self referencing information, - * - * which causes a cycle in system catalog cache + * This call searches for self-referencing information, + * which causes infinite recursion in the system catalog cache. + * This code short-circuits the normal index lookup for cache loads + * in those cases and replaces it with a heap scan. * * cache should already be initailized * -------------------------------- @@ -823,45 +824,81 @@ SearchSelfReferences(struct catcache * cache) { HeapTuple ntp; Relation rel; - static Oid indexSelfOid = 0; - static HeapTuple indexSelfTuple = 0; - - if (cache->id != INDEXRELID) - return (HeapTuple)0; - if (!indexSelfOid) + if (cache->id == INDEXRELID) { - rel = heap_openr(RelationRelationName, AccessShareLock); - ntp = ClassNameIndexScan(rel, IndexRelidIndex); - if (!HeapTupleIsValid(ntp)) - elog(ERROR, "SearchSelfRefernces: %s not found in %s", - IndexRelidIndex, RelationRelationName); - indexSelfOid = ntp->t_data->t_oid; - pfree(ntp); - heap_close(rel, AccessShareLock); + static Oid indexSelfOid = InvalidOid; + static HeapTuple indexSelfTuple = NULL; + + if (!OidIsValid(indexSelfOid)) + { + /* Find oid of pg_index_indexrelid_index */ + rel = heap_openr(RelationRelationName, AccessShareLock); + ntp = ClassNameIndexScan(rel, IndexRelidIndex); + if (!HeapTupleIsValid(ntp)) + elog(ERROR, "SearchSelfReferences: %s not found in %s", + IndexRelidIndex, RelationRelationName); + indexSelfOid = ntp->t_data->t_oid; + pfree(ntp); + heap_close(rel, AccessShareLock); + } + /* Looking for something other than pg_index_indexrelid_index? */ + if ((Oid)cache->cc_skey[0].sk_argument != indexSelfOid) + return (HeapTuple)0; + + /* Do we need to load our private copy of the tuple? */ + if (!HeapTupleIsValid(indexSelfTuple)) + { + HeapScanDesc sd; + MemoryContext oldcxt; + + if (!CacheCxt) + CacheCxt = CreateGlobalMemory("Cache"); + rel = heap_open(cache->relationId, AccessShareLock); + sd = heap_beginscan(rel, false, SnapshotNow, 1, cache->cc_skey); + ntp = heap_getnext(sd, 0); + if (!HeapTupleIsValid(ntp)) + elog(ERROR, "SearchSelfReferences: tuple not found"); + oldcxt = MemoryContextSwitchTo((MemoryContext) CacheCxt); + indexSelfTuple = heap_copytuple(ntp); + MemoryContextSwitchTo(oldcxt); + heap_endscan(sd); + heap_close(rel, AccessShareLock); + } + return indexSelfTuple; } - if ((Oid)cache->cc_skey[0].sk_argument != indexSelfOid) - return (HeapTuple)0; - if (!indexSelfTuple) + else if (cache->id == OPEROID) { - HeapScanDesc sd; - MemoryContext oldcxt; - - if (!CacheCxt) - CacheCxt = CreateGlobalMemory("Cache"); - rel = heap_open(cache->relationId, AccessShareLock); - sd = heap_beginscan(rel, false, SnapshotNow, 1, cache->cc_skey); - ntp = heap_getnext(sd, 0); - if (!HeapTupleIsValid(ntp)) - elog(ERROR, "SearchSelfRefernces: tuple not found"); - oldcxt = MemoryContextSwitchTo((MemoryContext) CacheCxt); - indexSelfTuple = heap_copytuple(ntp); - MemoryContextSwitchTo(oldcxt); - heap_endscan(sd); - heap_close(rel, AccessShareLock); + /* bootstrapping this requires preloading a range of rows. bjm */ + static HeapTuple operatorSelfTuple[MAX_OIDCMP-MIN_OIDCMP+1]; + Oid lookup_oid = (Oid)cache->cc_skey[0].sk_argument; + + if (lookup_oid < MIN_OIDCMP || lookup_oid > MAX_OIDCMP) + return (HeapTuple)0; + + if (!HeapTupleIsValid(operatorSelfTuple[lookup_oid-MIN_OIDCMP])) + { + HeapScanDesc sd; + MemoryContext oldcxt; + + if (!CacheCxt) + CacheCxt = CreateGlobalMemory("Cache"); + rel = heap_open(cache->relationId, AccessShareLock); + sd = heap_beginscan(rel, false, SnapshotNow, 1, cache->cc_skey); + ntp = heap_getnext(sd, 0); + if (!HeapTupleIsValid(ntp)) + elog(ERROR, "SearchSelfReferences: tuple not found"); + oldcxt = MemoryContextSwitchTo((MemoryContext) CacheCxt); + operatorSelfTuple[lookup_oid-MIN_OIDCMP] = heap_copytuple(ntp); + MemoryContextSwitchTo(oldcxt); + heap_endscan(sd); + heap_close(rel, AccessShareLock); + } + return operatorSelfTuple[lookup_oid-MIN_OIDCMP]; } + else + return (HeapTuple)0; - return indexSelfTuple; } /* -------------------------------- @@ -907,10 +944,8 @@ SearchSysCache(struct catcache * cache, /* * resolve self referencing informtion */ - if (ntp = SearchSelfReferences(cache), ntp) - { - return heap_copytuple(ntp); - } + if ((ntp = SearchSelfReferences(cache))) + return heap_copytuple(ntp); /* ---------------- * find the hash bucket in which to look for the tuple |