1 files changed, 30 insertions, 17 deletions

diff --git a/src/backend/executor/nodeSubplan.c b/src/backend/executor/nodeSubplan.c
index 3ebb045f922..338d94e7608 100644
--- a/src/backend/executor/nodeSubplan.c
+++ b/src/backend/executor/nodeSubplan.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/nodeSubplan.c,v 1.94 2008/08/22 00:16:03 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/nodeSubplan.c,v 1.95 2008/10/04 21:56:53 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -66,9 +66,13 @@ ExecSubPlan(SubPlanState *node,
 	if (isDone)
 		*isDone = ExprSingleResult;
 
+	/* Sanity checks */
+	if (subplan->subLinkType == CTE_SUBLINK)
+		elog(ERROR, "CTE subplans should not be executed via ExecSubPlan");
 	if (subplan->setParam != NIL)
 		elog(ERROR, "cannot set parent params from subquery");
 
+	/* Select appropriate evaluation strategy */
 	if (subplan->useHashTable)
 		return ExecHashSubPlan(node, econtext, isNull);
 	else
@@ -688,11 +692,14 @@ ExecInitSubPlan(SubPlan *subplan, PlanState *parent)
 	 * If this plan is un-correlated or undirect correlated one and want to
 	 * set params for parent plan then mark parameters as needing evaluation.
 	 *
+	 * A CTE subplan's output parameter is never to be evaluated in the normal
+	 * way, so skip this in that case.
+	 *
 	 * Note that in the case of un-correlated subqueries we don't care about
 	 * setting parent->chgParam here: indices take care about it, for others -
 	 * it doesn't matter...
 	 */
-	if (subplan->setParam != NIL)
+	if (subplan->setParam != NIL && subplan->subLinkType != CTE_SUBLINK)
 	{
 		ListCell   *lst;
 
@@ -907,22 +914,21 @@ ExecSetParamPlan(SubPlanState *node, ExprContext *econtext)
 	bool		found = false;
 	ArrayBuildState *astate = NULL;
 
-	/*
-	 * Must switch to per-query memory context.
-	 */
-	oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_query_memory);
-
 	if (subLinkType == ANY_SUBLINK ||
 		subLinkType == ALL_SUBLINK)
 		elog(ERROR, "ANY/ALL subselect unsupported as initplan");
+	if (subLinkType == CTE_SUBLINK)
+		elog(ERROR, "CTE subplans should not be executed via ExecSetParamPlan");
 
 	/*
-	 * By definition, an initplan has no parameters from our query level, but
-	 * it could have some from an outer level.	Rescan it if needed.
+	 * Must switch to per-query memory context.
 	 */
-	if (planstate->chgParam != NULL)
-		ExecReScan(planstate, NULL);
+	oldcontext = MemoryContextSwitchTo(econtext->ecxt_per_query_memory);
 
+	/*
+	 * Run the plan.  (If it needs to be rescanned, the first ExecProcNode
+	 * call will take care of that.)
+	 */
 	for (slot = ExecProcNode(planstate);
 		 !TupIsNull(slot);
 		 slot = ExecProcNode(planstate))
@@ -932,7 +938,7 @@ ExecSetParamPlan(SubPlanState *node, ExprContext *econtext)
 
 		if (subLinkType == EXISTS_SUBLINK)
 		{
-			/* There can be only one param... */
+			/* There can be only one setParam... */
 			int			paramid = linitial_int(subplan->setParam);
 			ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]);
 
@@ -994,7 +1000,7 @@ ExecSetParamPlan(SubPlanState *node, ExprContext *econtext)
 
 	if (subLinkType == ARRAY_SUBLINK)
 	{
-		/* There can be only one param... */
+		/* There can be only one setParam... */
 		int			paramid = linitial_int(subplan->setParam);
 		ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]);
 
@@ -1014,7 +1020,7 @@ ExecSetParamPlan(SubPlanState *node, ExprContext *econtext)
 	{
 		if (subLinkType == EXISTS_SUBLINK)
 		{
-			/* There can be only one param... */
+			/* There can be only one setParam... */
 			int			paramid = linitial_int(subplan->setParam);
 			ParamExecData *prm = &(econtext->ecxt_param_exec_vals[paramid]);
 
@@ -1059,18 +1065,25 @@ ExecReScanSetParamPlan(SubPlanState *node, PlanState *parent)
 		elog(ERROR, "extParam set of initplan is empty");
 
 	/*
-	 * Don't actually re-scan: ExecSetParamPlan does it if needed.
+	 * Don't actually re-scan: it'll happen inside ExecSetParamPlan if needed.
 	 */
 
 	/*
-	 * Mark this subplan's output parameters as needing recalculation
+	 * Mark this subplan's output parameters as needing recalculation.
+	 *
+	 * CTE subplans are never executed via parameter recalculation; instead
+	 * they get run when called by nodeCtescan.c.  So don't mark the output
+	 * parameter of a CTE subplan as dirty, but do set the chgParam bit
+	 * for it so that dependent plan nodes will get told to rescan.
 	 */
 	foreach(l, subplan->setParam)
 	{
 		int			paramid = lfirst_int(l);
 		ParamExecData *prm = &(estate->es_param_exec_vals[paramid]);
 
-		prm->execPlan = node;
+		if (subplan->subLinkType != CTE_SUBLINK)
+			prm->execPlan = node;
+
 		parent->chgParam = bms_add_member(parent->chgParam, paramid);
 	}
 }