A bunch of changes aimed at reducing backend startup time...

Improve 'pg_internal.init' relcache entry preload mechanism so that it is
safe to use for all system catalogs, and arrange to preload a realistic
set of system-catalog entries instead of only the three nailed-in-cache
indexes that were formerly loaded this way.  Fix mechanism for deleting
out-of-date pg_internal.init files: this must be synchronized with transaction
commit, not just done at random times within transactions.  Drive it off
relcache invalidation mechanism so that no special-case tests are needed.

Cache additional information in relcache entries for indexes (their pg_index
tuples and index-operator OIDs) to eliminate repeated lookups.  Also cache
index opclass info at the per-opclass level to avoid repeated lookups during
relcache load.

Generalize 'systable scan' utilities originally developed by Hiroshi,
move them into genam.c, use in a number of places where there was formerly
ugly code for choosing either heap or index scan.  In particular this allows
simplification of the logic that prevents infinite recursion between syscache
and relcache during startup: we can easily switch to heapscans in relcache.c
when and where needed to avoid recursion, so IndexScanOK becomes simpler and
does not need any expensive initialization.

Eliminate useless opening of a heapscan data structure while doing an indexscan
(this saves an mdnblocks call and thus at least one kernel call).

1 files changed, 7 insertions, 34 deletions

diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c
index 663a2b22008..f3739487426 100644
--- a/src/backend/commands/cluster.c
+++ b/src/backend/commands/cluster.c
@@ -15,7 +15,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/cluster.c,v 1.71 2002/01/06 00:37:44 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/cluster.c,v 1.72 2002/02/19 20:11:12 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -61,7 +61,6 @@ cluster(char *oldrelname, char *oldindexname)
 				OIDNewHeap;
 	Relation	OldHeap,
 				OldIndex;
-	HeapTuple	tuple;
 	bool		istemp;
 	char		NewHeapName[NAMEDATALEN];
 	char		NewIndexName[NAMEDATALEN];
@@ -90,16 +89,9 @@ cluster(char *oldrelname, char *oldindexname)
 	/*
 	 * Check that index is in fact an index on the given relation
 	 */
-	tuple = SearchSysCache(INDEXRELID,
-						   ObjectIdGetDatum(OIDOldIndex),
-						   0, 0, 0);
-	if (!HeapTupleIsValid(tuple))
-		elog(ERROR, "CLUSTER: no pg_index entry for index %u",
-			 OIDOldIndex);
-	if (((Form_pg_index) GETSTRUCT(tuple))->indrelid != OIDOldHeap)
+	if (OldIndex->rd_index->indrelid != OIDOldHeap)
 		elog(ERROR, "CLUSTER: \"%s\" is not an index for table \"%s\"",
 			 saveoldindexname, saveoldrelname);
-	ReleaseSysCache(tuple);
 
 	/* Drop relcache refcnts, but do NOT give up the locks */
 	heap_close(OldHeap, NoLock);
@@ -188,10 +180,6 @@ copy_index(Oid OIDOldIndex, Oid OIDNewHeap, char *NewIndexName)
 {
 	Relation	OldIndex,
 				NewHeap;
-	HeapTuple	Old_pg_index_Tuple,
-				Old_pg_index_relation_Tuple;
-	Form_pg_index Old_pg_index_Form;
-	Form_pg_class Old_pg_index_relation_Form;
 	IndexInfo  *indexInfo;
 
 	NewHeap = heap_open(OIDNewHeap, AccessExclusiveLock);
@@ -206,33 +194,18 @@ copy_index(Oid OIDOldIndex, Oid OIDNewHeap, char *NewIndexName)
 	 * its parent table is, so we don't need to do anything special for
 	 * the temp-table case here.
 	 */
-	Old_pg_index_Tuple = SearchSysCache(INDEXRELID,
-										ObjectIdGetDatum(OIDOldIndex),
-										0, 0, 0);
-	Assert(Old_pg_index_Tuple);
-	Old_pg_index_Form = (Form_pg_index) GETSTRUCT(Old_pg_index_Tuple);
-
-	indexInfo = BuildIndexInfo(Old_pg_index_Tuple);
-
-	Old_pg_index_relation_Tuple = SearchSysCache(RELOID,
-										   ObjectIdGetDatum(OIDOldIndex),
-												 0, 0, 0);
-	Assert(Old_pg_index_relation_Tuple);
-	Old_pg_index_relation_Form = (Form_pg_class) GETSTRUCT(Old_pg_index_relation_Tuple);
+	indexInfo = BuildIndexInfo(OldIndex->rd_index);
 
 	index_create(RelationGetRelationName(NewHeap),
 				 NewIndexName,
 				 indexInfo,
-				 Old_pg_index_relation_Form->relam,
-				 Old_pg_index_Form->indclass,
-				 Old_pg_index_Form->indisprimary,
+				 OldIndex->rd_rel->relam,
+				 OldIndex->rd_index->indclass,
+				 OldIndex->rd_index->indisprimary,
 				 allowSystemTableMods);
 
 	setRelhasindex(OIDNewHeap, true,
-				   Old_pg_index_Form->indisprimary, InvalidOid);
-
-	ReleaseSysCache(Old_pg_index_Tuple);
-	ReleaseSysCache(Old_pg_index_relation_Tuple);
+				   OldIndex->rd_index->indisprimary, InvalidOid);
 
 	index_close(OldIndex);
 	heap_close(NewHeap, NoLock);