Clean up handling of FOR UPDATE inside views and subselects ... make it

work where we can (given that the executor only handles it at top level)
and generate an error where we can't.  Note that while the parser has
been allowing views to say SELECT FOR UPDATE for a few weeks now, that
hasn't actually worked until just now.

src/backend/optimizer/plan/planner.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.96 2000/11/12 00:36:58 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.97 2000/12/06 23:55:17 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -25,6 +25,7 @@
 #include "optimizer/subselect.h"
 #include "optimizer/tlist.h"
 #include "optimizer/var.h"
+#include "parser/analyze.h"
 #include "parser/parsetree.h"
 #include "parser/parse_expr.h"
 #include "rewrite/rewriteManip.h"
@@ -255,6 +256,7 @@ pull_up_subqueries(Query *parse, Node *jtnode)
 			int		rtoffset;
 			Node   *subjointree;
 			List   *subtlist;
+			List   *l;
 
 			/*
 			 * First, recursively pull up the subquery's subqueries,
@@ -289,10 +291,22 @@ pull_up_subqueries(Query *parse, Node *jtnode)
 			parse->havingQual =
 				ResolveNew(parse->havingQual,
 						   varno, 0, subtlist, CMD_SELECT, 0);
+			/*
+			 * Pull up any FOR UPDATE markers, too.
+			 */
+			foreach(l, subquery->rowMarks)
+			{
+				int		submark = lfirsti(l);
+
+				parse->rowMarks = lappendi(parse->rowMarks,
+										   submark + rtoffset);
+			}
 			/*
 			 * Miscellaneous housekeeping.
 			 */
 			parse->hasSubLinks |= subquery->hasSubLinks;
+			/* subquery won't be pulled up if it hasAggs, so no work there */
+
 			/*
 			 * Return the adjusted subquery jointree to replace the
 			 * RangeTblRef entry in my jointree.
@@ -340,11 +354,6 @@ is_simple_subquery(Query *subquery)
 		subquery->into != NULL ||
 		subquery->isPortal)
 		elog(ERROR, "is_simple_subquery: subquery is bogus");
-	/*
-	 * Also check for currently-unsupported features.
-	 */
-	if (subquery->rowMarks)
-		elog(ERROR, "FOR UPDATE is not supported in subselects");
 	/*
 	 * Can't currently pull up a query with setops.
 	 * Maybe after querytree redesign...
@@ -707,6 +716,13 @@ grouping_planner(Query *parse, double tuple_fraction)
 
 		tlist = postprocess_setop_tlist(result_plan->targetlist, tlist);
 
+		/*
+		 * Can't handle FOR UPDATE here (parser should have checked already,
+		 * but let's make sure).
+		 */
+		if (parse->rowMarks)
+			elog(ERROR, "SELECT FOR UPDATE is not allowed with UNION/INTERSECT/EXCEPT");
+
 		/*
 		 * We set current_pathkeys NIL indicating we do not know sort
 		 * order.  This is correct when the top set operation is UNION ALL,
@@ -744,6 +760,18 @@ grouping_planner(Query *parse, double tuple_fraction)
 		{
 			List	   *l;
 
+			/*
+			 * We've got trouble if the FOR UPDATE appears inside grouping,
+			 * since grouping renders a reference to individual tuple CTIDs
+			 * invalid.  This is also checked at parse time, but that's
+			 * insufficient because of rule substitution, query pullup, etc.
+			 */
+			CheckSelectForUpdate(parse);
+
+			/* Currently the executor only supports FOR UPDATE at top level */
+			if (PlannerQueryLevel > 1)
+				elog(ERROR, "SELECT FOR UPDATE is not allowed in subselects");
+
 			foreach(l, parse->rowMarks)
 			{
 				Index		rti = lfirsti(l);

src/backend/parser/analyze.c

@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- *	$Id: analyze.c,v 1.170 2000/12/05 19:57:55 tgl Exp $
+ *	$Id: analyze.c,v 1.171 2000/12/06 23:55:19 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -37,8 +37,6 @@
 #include "mb/pg_wchar.h"
 #endif
 
-void		CheckSelectForUpdate(Query *qry);	/* no points for style... */
-
 static Query *transformStmt(ParseState *pstate, Node *stmt);
 static Query *transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt);
 static Query *transformInsertStmt(ParseState *pstate, InsertStmt *stmt);

src/backend/rewrite/rewriteHandler.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.84 2000/12/05 19:15:09 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteHandler.c,v 1.85 2000/12/06 23:55:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -31,9 +31,6 @@
 #include "utils/lsyscache.h"
 
 
-extern void CheckSelectForUpdate(Query *rule_action);	/* in analyze.c */
-
-
 static RewriteInfo *gatherRewriteMeta(Query *parsetree,
 				  Query *rule_action,
 				  Node *rule_qual,
@@ -100,29 +97,6 @@ gatherRewriteMeta(Query *parsetree,
 	ChangeVarNodes(info->rule_qual,
 				   PRS2_OLD_VARNO + rt_length, rt_index, 0);
 
-	/*
-	 * Update resultRelation too ... perhaps this should be done by
-	 * Offset/ChangeVarNodes?
-	 */
-	if (sub_action->resultRelation)
-	{
-		int			result_reln;
-		int			new_result_reln;
-
-		result_reln = sub_action->resultRelation;
-		switch (result_reln)
-		{
-			case PRS2_OLD_VARNO:
-				new_result_reln = rt_index;
-				break;
-			case PRS2_NEW_VARNO:
-			default:
-				new_result_reln = result_reln + rt_length;
-				break;
-		}
-		sub_action->resultRelation = new_result_reln;
-	}
-
 	/*
 	 * We want the main parsetree's rtable to end up as the concatenation
 	 * of its original contents plus those of all the relevant rule
@@ -336,8 +310,6 @@ ApplyRetrieveRule(Query *parsetree,
 	{
 		Index		innerrti = 1;
 
-		CheckSelectForUpdate(rule_action);
-
 		/*
 		 * Remove the view from the list of rels that will actually be
 		 * marked FOR UPDATE by the executor.  It will still be access-

src/backend/rewrite/rewriteManip.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteManip.c,v 1.52 2000/12/05 19:15:09 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteManip.c,v 1.53 2000/12/06 23:55:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -169,8 +169,29 @@ OffsetVarNodes(Node *node, int offset, int sublevels_up)
 	 * sublevels_up doesn't get incremented prematurely.
 	 */
 	if (node && IsA(node, Query))
-		query_tree_walker((Query *) node, OffsetVarNodes_walker,
+	{
+		Query  *qry = (Query *) node;
+		List   *l;
+
+		/*
+		 * If we are starting at a Query, and sublevels_up is zero, then we
+		 * must also fix rangetable indexes in the Query itself --- namely
+		 * resultRelation and rowMarks entries.  sublevels_up cannot be zero
+		 * when recursing into a subquery, so there's no need to have the
+		 * same logic inside OffsetVarNodes_walker.
+		 */
+		if (sublevels_up == 0)
+		{
+			if (qry->resultRelation)
+				qry->resultRelation += offset;
+			foreach(l, qry->rowMarks)
+			{
+				lfirsti(l) += offset;
+			}
+		}
+		query_tree_walker(qry, OffsetVarNodes_walker,
 						  (void *) &context, true);
+	}
 	else
 		OffsetVarNodes_walker(node, &context);
 }
@@ -252,8 +273,30 @@ ChangeVarNodes(Node *node, int rt_index, int new_index, int sublevels_up)
 	 * sublevels_up doesn't get incremented prematurely.
 	 */
 	if (node && IsA(node, Query))
-		query_tree_walker((Query *) node, ChangeVarNodes_walker,
+	{
+		Query  *qry = (Query *) node;
+		List   *l;
+
+		/*
+		 * If we are starting at a Query, and sublevels_up is zero, then we
+		 * must also fix rangetable indexes in the Query itself --- namely
+		 * resultRelation and rowMarks entries.  sublevels_up cannot be zero
+		 * when recursing into a subquery, so there's no need to have the
+		 * same logic inside ChangeVarNodes_walker.
+		 */
+		if (sublevels_up == 0)
+		{
+			if (qry->resultRelation == rt_index)
+				qry->resultRelation = new_index;
+			foreach(l, qry->rowMarks)
+			{
+				if (lfirsti(l) == rt_index)
+					lfirsti(l) = new_index;
+			}
+		}
+		query_tree_walker(qry, ChangeVarNodes_walker,
 						  (void *) &context, true);
+	}
 	else
 		ChangeVarNodes_walker(node, &context);
 }

src/include/parser/analyze.h

@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: analyze.h,v 1.12 2000/10/07 00:58:21 tgl Exp $
+ * $Id: analyze.h,v 1.13 2000/12/06 23:55:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -17,4 +17,6 @@
 
 extern List *parse_analyze(Node *parseTree, ParseState *parentParseState);
 
+extern void CheckSelectForUpdate(Query *qry);
+
 #endif	 /* ANALYZE_H */