Eliminate pg_rewrite.ev_attr column and related dead code.

Commit 95ef6a344821655ce4d0a74999ac49dd6af6d342 removed the
ability to create rules on an individual column as of 7.3, but
left some residual code which has since been useless.  This cleans
up that dead code without any change in behavior other than
dropping the useless column from the catalog.

doc/src/sgml/catalogs.sgml

@@ -5038,14 +5038,6 @@
       <entry>The table this rule is for</entry>
      </row>
 
-     <row>
-      <entry><structfield>ev_attr</structfield></entry>
-      <entry><type>int2</type></entry>
-      <entry></entry>
-      <entry>The column this rule is for (currently, always -1 to
-      indicate the whole table)</entry>
-     </row>
-
      <row>
       <entry><structfield>ev_type</structfield></entry>
       <entry><type>char</type></entry>

src/backend/rewrite/rewriteDefine.c

@@ -58,7 +58,6 @@ static Oid
 InsertRule(char *rulname,
 		   int evtype,
 		   Oid eventrel_oid,
-		   AttrNumber evslot_index,
 		   bool evinstead,
 		   Node *event_qual,
 		   List *action,
@@ -86,7 +85,6 @@ InsertRule(char *rulname,
 	namestrcpy(&rname, rulname);
 	values[Anum_pg_rewrite_rulename - 1] = NameGetDatum(&rname);
 	values[Anum_pg_rewrite_ev_class - 1] = ObjectIdGetDatum(eventrel_oid);
-	values[Anum_pg_rewrite_ev_attr - 1] = Int16GetDatum(evslot_index);
 	values[Anum_pg_rewrite_ev_type - 1] = CharGetDatum(evtype + '0');
 	values[Anum_pg_rewrite_ev_enabled - 1] = CharGetDatum(RULE_FIRES_ON_ORIGIN);
 	values[Anum_pg_rewrite_is_instead - 1] = BoolGetDatum(evinstead);
@@ -117,7 +115,6 @@ InsertRule(char *rulname,
 		 * When replacing, we don't need to replace every attribute
 		 */
 		MemSet(replaces, false, sizeof(replaces));
-		replaces[Anum_pg_rewrite_ev_attr - 1] = true;
 		replaces[Anum_pg_rewrite_ev_type - 1] = true;
 		replaces[Anum_pg_rewrite_is_instead - 1] = true;
 		replaces[Anum_pg_rewrite_ev_qual - 1] = true;
@@ -238,7 +235,6 @@ DefineQueryRewrite(char *rulename,
 				   List *action)
 {
 	Relation	event_relation;
-	int			event_attno;
 	ListCell   *l;
 	Query	   *query;
 	bool		RelisBecomingView = false;
@@ -495,7 +491,6 @@ DefineQueryRewrite(char *rulename,
 	/*
 	 * This rule is allowed - prepare to install it.
 	 */
-	event_attno = -1;
 
 	/* discard rule if it's null action and not INSTEAD; it's a no-op */
 	if (action != NIL || is_instead)
@@ -503,7 +498,6 @@ DefineQueryRewrite(char *rulename,
 		ruleId = InsertRule(rulename,
 							event_type,
 							event_relid,
-							event_attno,
 							is_instead,
 							event_qual,
 							action,

src/backend/rewrite/rewriteHandler.c

@@ -1276,10 +1276,7 @@ matchLocks(CmdType event,
 		if (oneLock->event == event)
 		{
 			if (parsetree->commandType != CMD_SELECT ||
-				(oneLock->attrno == -1 ?
-				 rangeTableEntry_used((Node *) parsetree, varno, 0) :
-				 attribute_used((Node *) parsetree,
-								varno, oneLock->attrno, 0)))
+				rangeTableEntry_used((Node *) parsetree, varno, 0))
 				matching_locks = lappend(matching_locks, oneLock);
 		}
 	}
@@ -1295,7 +1292,6 @@ static Query *
 ApplyRetrieveRule(Query *parsetree,
 				  RewriteRule *rule,
 				  int rt_index,
-				  bool relation_level,
 				  Relation relation,
 				  List *activeRIRs,
 				  bool forUpdatePushedDown)
@@ -1309,8 +1305,6 @@ ApplyRetrieveRule(Query *parsetree,
 		elog(ERROR, "expected just one rule action");
 	if (rule->qual != NULL)
 		elog(ERROR, "cannot handle qualified ON SELECT rule");
-	if (!relation_level)
-		elog(ERROR, "cannot handle per-attribute ON SELECT rule");
 
 	if (rt_index == parsetree->resultRelation)
 	{
@@ -1632,14 +1626,6 @@ fireRIRrules(Query *parsetree, List *activeRIRs, bool forUpdatePushedDown)
 			if (rule->event != CMD_SELECT)
 				continue;
 
-			if (rule->attrno > 0)
-			{
-				/* per-attr rule; do we need it? */
-				if (!attribute_used((Node *) parsetree, rt_index,
-									rule->attrno, 0))
-					continue;
-			}
-
 			locks = lappend(locks, rule);
 		}
 
@@ -1664,7 +1650,6 @@ fireRIRrules(Query *parsetree, List *activeRIRs, bool forUpdatePushedDown)
 				parsetree = ApplyRetrieveRule(parsetree,
 											  rule,
 											  rt_index,
-											  rule->attrno == -1,
 											  rel,
 											  activeRIRs,
 											  forUpdatePushedDown);

src/backend/rewrite/rewriteManip.c

@@ -857,70 +857,6 @@ rangeTableEntry_used(Node *node, int rt_index, int sublevels_up)
 }
 
 
-/*
- * attribute_used -
- *	Check if a specific attribute number of a RTE is used
- *	somewhere in the query or expression.
- */
-
-typedef struct
-{
-	int			rt_index;
-	int			attno;
-	int			sublevels_up;
-} attribute_used_context;
-
-static bool
-attribute_used_walker(Node *node,
-					  attribute_used_context *context)
-{
-	if (node == NULL)
-		return false;
-	if (IsA(node, Var))
-	{
-		Var		   *var = (Var *) node;
-
-		if (var->varlevelsup == context->sublevels_up &&
-			var->varno == context->rt_index &&
-			var->varattno == context->attno)
-			return true;
-		return false;
-	}
-	if (IsA(node, Query))
-	{
-		/* Recurse into subselects */
-		bool		result;
-
-		context->sublevels_up++;
-		result = query_tree_walker((Query *) node, attribute_used_walker,
-								   (void *) context, 0);
-		context->sublevels_up--;
-		return result;
-	}
-	return expression_tree_walker(node, attribute_used_walker,
-								  (void *) context);
-}
-
-bool
-attribute_used(Node *node, int rt_index, int attno, int sublevels_up)
-{
-	attribute_used_context context;
-
-	context.rt_index = rt_index;
-	context.attno = attno;
-	context.sublevels_up = sublevels_up;
-
-	/*
-	 * Must be prepared to start with a Query or a bare expression tree; if
-	 * it's a Query, we don't want to increment sublevels_up.
-	 */
-	return query_or_expression_tree_walker(node,
-										   attribute_used_walker,
-										   (void *) &context,
-										   0);
-}
-
-
 /*
  * If the given Query is an INSERT ... SELECT construct, extract and
  * return the sub-Query node that represents the SELECT part.  Otherwise

src/backend/utils/adt/ruleutils.c

@@ -3734,7 +3734,6 @@ make_ruledef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc,
 	char	   *rulename;
 	char		ev_type;
 	Oid			ev_class;
-	int16		ev_attr;
 	bool		is_instead;
 	char	   *ev_qual;
 	char	   *ev_action;
@@ -3761,11 +3760,6 @@ make_ruledef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc,
 	Assert(!isnull);
 	ev_class = DatumGetObjectId(dat);
 
-	fno = SPI_fnumber(rulettc, "ev_attr");
-	dat = SPI_getbinval(ruletup, rulettc, fno, &isnull);
-	Assert(!isnull);
-	ev_attr = DatumGetInt16(dat);
-
 	fno = SPI_fnumber(rulettc, "is_instead");
 	dat = SPI_getbinval(ruletup, rulettc, fno, &isnull);
 	Assert(!isnull);
@@ -3820,10 +3814,6 @@ make_ruledef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc,
 
 	/* The relation the rule is fired on */
 	appendStringInfo(buf, " TO %s", generate_relation_name(ev_class, NIL));
-	if (ev_attr > 0)
-		appendStringInfo(buf, ".%s",
-						 quote_identifier(get_relid_attribute_name(ev_class,
-																   ev_attr)));
 
 	/* If the rule has an event qualification, add it */
 	if (ev_qual == NULL)
@@ -3925,7 +3915,6 @@ make_viewdef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc,
 	Query	   *query;
 	char		ev_type;
 	Oid			ev_class;
-	int16		ev_attr;
 	bool		is_instead;
 	char	   *ev_qual;
 	char	   *ev_action;
@@ -3943,9 +3932,6 @@ make_viewdef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc,
 	fno = SPI_fnumber(rulettc, "ev_class");
 	ev_class = (Oid) SPI_getbinval(ruletup, rulettc, fno, &isnull);
 
-	fno = SPI_fnumber(rulettc, "ev_attr");
-	ev_attr = (int16) SPI_getbinval(ruletup, rulettc, fno, &isnull);
-
 	fno = SPI_fnumber(rulettc, "is_instead");
 	is_instead = (bool) SPI_getbinval(ruletup, rulettc, fno, &isnull);
 
@@ -3965,7 +3951,7 @@ make_viewdef(StringInfo buf, HeapTuple ruletup, TupleDesc rulettc,
 
 	query = (Query *) linitial(actions);
 
-	if (ev_type != '1' || ev_attr >= 0 || !is_instead ||
+	if (ev_type != '1' || !is_instead ||
 		strcmp(ev_qual, "<>") != 0 || query->commandType != CMD_SELECT)
 	{
 		appendStringInfo(buf, "Not a view");

src/backend/utils/cache/relcache.c

@@ -682,7 +682,6 @@ RelationBuildRuleLock(Relation relation)
 		rule->ruleId = HeapTupleGetOid(rewrite_tuple);
 
 		rule->event = rewrite_form->ev_type - '0';
-		rule->attrno = rewrite_form->ev_attr;
 		rule->enabled = rewrite_form->ev_enabled;
 		rule->isInstead = rewrite_form->is_instead;
 
@@ -798,8 +797,6 @@ equalRuleLocks(RuleLock *rlock1, RuleLock *rlock2)
 				return false;
 			if (rule1->event != rule2->event)
 				return false;
-			if (rule1->attrno != rule2->attrno)
-				return false;
 			if (rule1->enabled != rule2->enabled)
 				return false;
 			if (rule1->isInstead != rule2->isInstead)

src/include/catalog/catversion.h

@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201309031
+#define CATALOG_VERSION_NO	201309051
 
 #endif

src/include/catalog/pg_rewrite.h

@@ -35,7 +35,6 @@ CATALOG(pg_rewrite,2618)
 {
 	NameData	rulename;
 	Oid			ev_class;
-	int16		ev_attr;
 	char		ev_type;
 	char		ev_enabled;
 	bool		is_instead;
@@ -57,14 +56,13 @@ typedef FormData_pg_rewrite *Form_pg_rewrite;
  *		compiler constants for pg_rewrite
  * ----------------
  */
-#define Natts_pg_rewrite				8
+#define Natts_pg_rewrite				7
 #define Anum_pg_rewrite_rulename		1
 #define Anum_pg_rewrite_ev_class		2
-#define Anum_pg_rewrite_ev_attr			3
-#define Anum_pg_rewrite_ev_type			4
-#define Anum_pg_rewrite_ev_enabled		5
-#define Anum_pg_rewrite_is_instead		6
-#define Anum_pg_rewrite_ev_qual			7
-#define Anum_pg_rewrite_ev_action		8
+#define Anum_pg_rewrite_ev_type			3
+#define Anum_pg_rewrite_ev_enabled		4
+#define Anum_pg_rewrite_is_instead		5
+#define Anum_pg_rewrite_ev_qual			6
+#define Anum_pg_rewrite_ev_action		7
 
 #endif   /* PG_REWRITE_H */

src/include/rewrite/prs2lock.h

@@ -25,7 +25,6 @@ typedef struct RewriteRule
 {
 	Oid			ruleId;
 	CmdType		event;
-	AttrNumber	attrno;
 	Node	   *qual;
 	List	   *actions;
 	char		enabled;

src/include/rewrite/rewriteManip.h

@@ -49,8 +49,6 @@ extern void IncrementVarSublevelsUp_rtable(List *rtable,
 
 extern bool rangeTableEntry_used(Node *node, int rt_index,
 					 int sublevels_up);
-extern bool attribute_used(Node *node, int rt_index, int attno,
-			   int sublevels_up);
 
 extern Query *getInsertSelectQuery(Query *parsetree, Query ***subquery_ptr);
 

src/tools/pgindent/typedefs.list

@@ -1955,7 +1955,6 @@ adjust_appendrel_attrs_context
 allocfunc
 array_unnest_fctx
 assign_collations_context
-attribute_used_context
 autovac_table
 av_relation
 avl_dbase