Code review and documentation updates for indisclustered patch.

doc/src/sgml/catalogs.sgml

 <!--
  Documentation of the system catalogs, directed toward PostgreSQL developers
- $Header: /cvsroot/pgsql/doc/src/sgml/catalogs.sgml,v 2.58 2002/09/02 05:52:34 momjian Exp $
+ $Header: /cvsroot/pgsql/doc/src/sgml/catalogs.sgml,v 2.59 2002/09/03 01:04:40 tgl Exp $
  -->
 
 <chapter id="catalogs">
@@ -1865,7 +1865,7 @@
       <entry>indisclustered</entry>
       <entry><type>bool</type></entry>
       <entry></entry>
-      <entry>unused</entry>
+      <entry>If true, the table was last clustered on this index.</entry>
      </row>
 
      <row>

src/backend/catalog/index.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/catalog/index.c,v 1.193 2002/09/02 01:05:04 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/catalog/index.c,v 1.194 2002/09/03 01:04:41 tgl Exp $
  *
  *
  * INTERFACE ROUTINES
@@ -453,7 +453,7 @@ UpdateIndexRelation(Oid indexoid,
 	indexForm->indexrelid = indexoid;
 	indexForm->indrelid = heapoid;
 	indexForm->indproc = indexInfo->ii_FuncOid;
-	indexForm->indisclustered = false;	/* not used */
+	indexForm->indisclustered = false;	/* not clustered, yet */
 	indexForm->indisunique = indexInfo->ii_Unique;
 	indexForm->indisprimary = primary;
 	memcpy((char *) &indexForm->indpred, (char *) predText, predLen);

src/backend/commands/cluster.c

@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/cluster.c,v 1.88 2002/09/02 01:05:04 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/cluster.c,v 1.89 2002/09/03 01:04:41 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -304,12 +304,7 @@ get_indexattr_list(Relation OldHeap, Oid OldIndex)
 			palloc(sizeof(Oid) * attrs->indexInfo->ii_NumIndexAttrs);
 		memcpy(attrs->classOID, indexForm->indclass,
 			   sizeof(Oid) * attrs->indexInfo->ii_NumIndexAttrs);
-
-		/* We'll set indisclustered at index creation time on the
-		 * index we are currently clustering, and reset it on other
-		 * indexes.
-		 */
-		attrs->isclustered = (OldIndex == indexOID ? true : false);
+		attrs->isclustered = (OldIndex == indexOID);
 
 		/* Name and access method of each index come from pg_class */
 		classTuple = SearchSysCache(RELOID,
@@ -373,19 +368,25 @@ recreate_indexattr(Oid OIDOldHeap, List *indexes)
 
 		CommandCounterIncrement();
 
-		/* Set indisclustered to the correct value.  Only one index is
-		 * allowed to be clustered.
+		/*
+		 * Make sure that indisclustered is correct: it should be set
+		 * only for the index we just clustered on.
 		 */
 		pg_index = heap_openr(IndexRelationName, RowExclusiveLock);
 		tuple = SearchSysCacheCopy(INDEXRELID,
 								   ObjectIdGetDatum(attrs->indexOID),
 								   0, 0, 0);
+		if (!HeapTupleIsValid(tuple))
+			elog(ERROR, "cache lookup failed for index %u", attrs->indexOID);
 		index = (Form_pg_index) GETSTRUCT(tuple);
+		if (index->indisclustered != attrs->isclustered)
+		{
 			index->indisclustered = attrs->isclustered;
 			simple_heap_update(pg_index, &tuple->t_self, tuple);
 			CatalogUpdateIndexes(pg_index, tuple);
+		}
 		heap_freetuple(tuple);
-		heap_close(pg_index, NoLock);
+		heap_close(pg_index, RowExclusiveLock);
 
 		/* Destroy new index with old filenode */
 		object.classId = RelOid_pg_class;

src/include/catalog/pg_index.h

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: pg_index.h,v 1.28 2002/06/20 20:29:44 momjian Exp $
+ * $Id: pg_index.h,v 1.29 2002/09/03 01:04:41 tgl Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -38,7 +38,7 @@ CATALOG(pg_index) BKI_WITHOUT_OIDS
 	regproc		indproc;		/* OID of function for functional index */
 	int2vector	indkey;			/* column numbers of indexed attributes */
 	oidvector	indclass;		/* opclass identifiers */
-	bool		indisclustered; /* presently unused */
+	bool		indisclustered; /* is this the index last clustered by? */
 	bool		indisunique;	/* is this a unique index? */
 	bool		indisprimary;	/* is this index for primary key? */
 	Oid			indreference;	/* oid of index of referenced relation (ie