Second phase of committing Rod Taylor's pg_depend/pg_constraint patch.

pg_relcheck is gone; CHECK, UNIQUE, PRIMARY KEY, and FOREIGN KEY
constraints all have real live entries in pg_constraint.  pg_depend
exists, and RESTRICT/CASCADE options work on most kinds of DROP;
however, pg_depend is not yet very well populated with dependencies.
(Most of the ones that are present at this point just replace formerly
hardwired associations, such as the implicit drop of a relation's pg_type
entry when the relation is dropped.)  Need to add more logic to create
dependency entries, improve pg_dump to dump constraints in place of
indexes and triggers, and add some regression tests.

1 files changed, 24 insertions, 13 deletions

diff --git a/src/backend/rewrite/rewriteSupport.c b/src/backend/rewrite/rewriteSupport.c
index ba590b8cc66..3f4c7f23871 100644
--- a/src/backend/rewrite/rewriteSupport.c
+++ b/src/backend/rewrite/rewriteSupport.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteSupport.c,v 1.52 2002/06/20 20:29:34 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteSupport.c,v 1.53 2002/07/12 18:43:17 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -18,6 +18,7 @@
 #include "catalog/catname.h"
 #include "catalog/indexing.h"
 #include "rewrite/rewriteSupport.h"
+#include "utils/inval.h"
 #include "utils/syscache.h"
 
 
@@ -44,9 +45,8 @@ IsDefinedRewriteRule(Oid owningRel, const char *ruleName)
  * NOTE: an important side-effect of this operation is that an SI invalidation
  * message is sent out to all backends --- including me --- causing relcache
  * entries to be flushed or updated with the new set of rules for the table.
- * Therefore, we execute the update even if relhasrules has the right value
- * already.  Possible future improvement: skip the disk update and just send
- * an SI message in that case.
+ * This must happen even if we find that no change is needed in the pg_class
+ * row.
  */
 void
 SetRelationRuleStatus(Oid relationId, bool relHasRules,
@@ -54,6 +54,7 @@ SetRelationRuleStatus(Oid relationId, bool relHasRules,
 {
 	Relation	relationRelation;
 	HeapTuple	tuple;
+	Form_pg_class classForm;
 	Relation	idescs[Num_pg_class_indices];
 
 	/*
@@ -66,18 +67,28 @@ SetRelationRuleStatus(Oid relationId, bool relHasRules,
 							   0, 0, 0);
 	if (!HeapTupleIsValid(tuple))
 		elog(ERROR, "SetRelationRuleStatus: cache lookup failed for relation %u", relationId);
+	classForm = (Form_pg_class) GETSTRUCT(tuple);
 
-	/* Do the update */
-	((Form_pg_class) GETSTRUCT(tuple))->relhasrules = relHasRules;
-	if (relIsBecomingView)
-		((Form_pg_class) GETSTRUCT(tuple))->relkind = RELKIND_VIEW;
+	if (classForm->relhasrules != relHasRules ||
+		(relIsBecomingView && classForm->relkind != RELKIND_VIEW))
+	{
+		/* Do the update */
+		classForm->relhasrules = relHasRules;
+		if (relIsBecomingView)
+			classForm->relkind = RELKIND_VIEW;
 
-	simple_heap_update(relationRelation, &tuple->t_self, tuple);
+		simple_heap_update(relationRelation, &tuple->t_self, tuple);
 
-	/* Keep the catalog indices up to date */
-	CatalogOpenIndices(Num_pg_class_indices, Name_pg_class_indices, idescs);
-	CatalogIndexInsert(idescs, Num_pg_class_indices, relationRelation, tuple);
-	CatalogCloseIndices(Num_pg_class_indices, idescs);
+		/* Keep the catalog indices up to date */
+		CatalogOpenIndices(Num_pg_class_indices, Name_pg_class_indices, idescs);
+		CatalogIndexInsert(idescs, Num_pg_class_indices, relationRelation, tuple);
+		CatalogCloseIndices(Num_pg_class_indices, idescs);
+	}
+	else
+	{
+		/* no need to change tuple, but force relcache rebuild anyway */
+		CacheInvalidateRelcache(relationId);
+	}
 
 	heap_freetuple(tuple);
 	heap_close(relationRelation, RowExclusiveLock);