Adjust more backend functions to return OID rather than void.

This is again intended to support extensions to the event trigger
functionality.  This may go a bit further than we need for that
purpose, but there's some value in being consistent, and the OID
may be useful for other purposes also.

Dimitri Fontaine

src/backend/rewrite/rewriteDefine.c

@@ -191,7 +191,7 @@ InsertRule(char *rulname,
  * DefineRule
  *		Execute a CREATE RULE command.
  */
-void
+Oid
 DefineRule(RuleStmt *stmt, const char *queryString)
 {
 	List	   *actions;
@@ -208,13 +208,13 @@ DefineRule(RuleStmt *stmt, const char *queryString)
 	relId = RangeVarGetRelid(stmt->relation, AccessExclusiveLock, false);
 
 	/* ... and execute */
-	DefineQueryRewrite(stmt->rulename,
-					   relId,
-					   whereClause,
-					   stmt->event,
-					   stmt->instead,
-					   stmt->replace,
-					   actions);
+	return DefineQueryRewrite(stmt->rulename,
+							  relId,
+							  whereClause,
+							  stmt->event,
+							  stmt->instead,
+							  stmt->replace,
+							  actions);
 }
 
 
@@ -225,7 +225,7 @@ DefineRule(RuleStmt *stmt, const char *queryString)
  * This is essentially the same as DefineRule() except that the rule's
  * action and qual have already been passed through parse analysis.
  */
-void
+Oid
 DefineQueryRewrite(char *rulename,
 				   Oid event_relid,
 				   Node *event_qual,
@@ -239,6 +239,7 @@ DefineQueryRewrite(char *rulename,
 	ListCell   *l;
 	Query	   *query;
 	bool		RelisBecomingView = false;
+	Oid         ruleId = InvalidOid;
 
 	/*
 	 * If we are installing an ON SELECT rule, we had better grab
@@ -489,14 +490,14 @@ DefineQueryRewrite(char *rulename,
 	/* discard rule if it's null action and not INSTEAD; it's a no-op */
 	if (action != NIL || is_instead)
 	{
-		InsertRule(rulename,
-				   event_type,
-				   event_relid,
-				   event_attno,
-				   is_instead,
-				   event_qual,
-				   action,
-				   replace);
+		ruleId = InsertRule(rulename,
+							event_type,
+							event_relid,
+							event_attno,
+							is_instead,
+							event_qual,
+							action,
+							replace);
 
 		/*
 		 * Set pg_class 'relhasrules' field TRUE for event relation. If
@@ -527,6 +528,8 @@ DefineQueryRewrite(char *rulename,
 
 	/* Close rel, but keep lock till commit... */
 	heap_close(event_relation, NoLock);
+
+	return ruleId;
 }
 
 /*