Improve the representation of FOR UPDATE/FOR SHARE so that we can

support both FOR UPDATE and FOR SHARE in one command, as well as both
NOWAIT and normal WAIT behavior.  The more general code is actually
simpler and cleaner.

3 files changed, 9 insertions, 29 deletions

diff --git a/src/backend/optimizer/prep/prepjointree.c b/src/backend/optimizer/prep/prepjointree.c
index ae538c9cc0..f3b6df46f2 100644
--- a/src/backend/optimizer/prep/prepjointree.c
+++ b/src/backend/optimizer/prep/prepjointree.c
@@ -15,7 +15,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/prep/prepjointree.c,v 1.37 2006/03/07 01:00:15 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/prep/prepjointree.c,v 1.38 2006/04/30 18:30:39 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -409,29 +409,9 @@ pull_up_simple_subquery(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte,
 
 	/*
 	 * Pull up any FOR UPDATE/SHARE markers, too.  (OffsetVarNodes
-	 * already adjusted the marker values, so just list_concat the
-	 * list.)
-	 *
-	 * Executor can't handle multiple FOR UPDATE/SHARE/NOWAIT flags,
-	 * so complain if they are valid but different
+	 * already adjusted the marker rtindexes, so just concat the lists.)
 	 */
-	if (parse->rowMarks && subquery->rowMarks)
-	{
-		if (parse->forUpdate != subquery->forUpdate)
-			ereport(ERROR,
-					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-					 errmsg("cannot use both FOR UPDATE and FOR SHARE in one query")));
-		if (parse->rowNoWait != subquery->rowNoWait)
-			ereport(ERROR,
-					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-					 errmsg("cannot use both wait and NOWAIT in one query")));
-	}
 	parse->rowMarks = list_concat(parse->rowMarks, subquery->rowMarks);
-	if (subquery->rowMarks)
-	{
-		parse->forUpdate = subquery->forUpdate;
-		parse->rowNoWait = subquery->rowNoWait;
-	}
 
 	/*
 	 * We also have to fix the relid sets of any parent InClauseInfo
diff --git a/src/backend/optimizer/prep/preptlist.c b/src/backend/optimizer/prep/preptlist.c
index 5a37b86eb5..0e06d0e888 100644
--- a/src/backend/optimizer/prep/preptlist.c
+++ b/src/backend/optimizer/prep/preptlist.c
@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/prep/preptlist.c,v 1.81 2006/04/05 22:11:55 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/prep/preptlist.c,v 1.82 2006/04/30 18:30:39 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -116,7 +116,7 @@ preprocess_targetlist(PlannerInfo *root, List *tlist)
 		 * invalid.  This is also checked at parse time, but that's
 		 * insufficient because of rule substitution, query pullup, etc.
 		 */
-		CheckSelectLocking(parse, parse->forUpdate);
+		CheckSelectLocking(parse);
 
 		/*
 		 * Currently the executor only supports FOR UPDATE/SHARE at top level
@@ -128,19 +128,19 @@ preprocess_targetlist(PlannerInfo *root, List *tlist)
 
 		foreach(l, parse->rowMarks)
 		{
-			Index		rti = lfirst_int(l);
+			RowMarkClause *rc = (RowMarkClause *) lfirst(l);
 			Var		   *var;
 			char	   *resname;
 			TargetEntry *tle;
 
-			var = makeVar(rti,
+			var = makeVar(rc->rti,
 						  SelfItemPointerAttributeNumber,
 						  TIDOID,
 						  -1,
 						  0);
 
 			resname = (char *) palloc(32);
-			snprintf(resname, 32, "ctid%u", rti);
+			snprintf(resname, 32, "ctid%u", rc->rti);
 
 			tle = makeTargetEntry((Expr *) var,
 								  list_length(tlist) + 1,
diff --git a/src/backend/optimizer/prep/prepunion.c b/src/backend/optimizer/prep/prepunion.c
index 8c0457295c..3b9e740cad 100644
--- a/src/backend/optimizer/prep/prepunion.c
+++ b/src/backend/optimizer/prep/prepunion.c
@@ -22,7 +22,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/prep/prepunion.c,v 1.131 2006/03/05 15:58:31 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/prep/prepunion.c,v 1.132 2006/04/30 18:30:39 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -816,7 +816,7 @@ expand_inherited_rtentry(PlannerInfo *root, RangeTblEntry *rte, Index rti)
 	 */
 	if (rti == parse->resultRelation)
 		lockmode = RowExclusiveLock;
-	else if (list_member_int(parse->rowMarks, rti))
+	else if (get_rowmark(parse, rti))
 		lockmode = RowShareLock;
 	else
 		lockmode = AccessShareLock;