diff --git a/src/backend/executor/nodeAgg.c b/src/backend/executor/nodeAgg.c
old mode 100644
new mode 100755
index 9ff0eff..fe3920e
--- a/src/backend/executor/nodeAgg.c
+++ b/src/backend/executor/nodeAgg.c
@@ -2053,10 +2053,10 @@ void
 ExecReScanAgg(AggState *node)
 {
 	ExprContext *econtext = node->ss.ps.ps_ExprContext;
+	PlanState	*outerPlan = outerPlanState(node);
 	int			aggno;
 
 	node->agg_done = false;
-
 	node->ss.ps.ps_TupFromTlist = false;
 
 	if (((Agg *) node->ss.ps.plan)->aggstrategy == AGG_HASHED)
@@ -2075,7 +2075,7 @@ ExecReScanAgg(AggState *node)
 		 * parameter changes, then we can just rescan the existing hash table;
 		 * no need to build it again.
 		 */
-		if (node->ss.ps.lefttree->chgParam == NULL)
+		if (outerPlan->chgParam == NULL)
 		{
 			ResetTupleHashIterator(node->hashtable, &node->hashiter);
 			return;
@@ -2133,8 +2133,8 @@ ExecReScanAgg(AggState *node)
 	 * if chgParam of subnode is not null then plan will be re-scanned by
 	 * first ExecProcNode.
 	 */
-	if (node->ss.ps.lefttree->chgParam == NULL)
-		ExecReScan(node->ss.ps.lefttree);
+	if (outerPlan->chgParam == NULL)
+		ExecReScan(outerPlan);
 }
 
 
diff --git a/src/backend/executor/nodeBitmapHeapscan.c b/src/backend/executor/nodeBitmapHeapscan.c
old mode 100644
new mode 100755
index 8ea8b9f..6502841
--- a/src/backend/executor/nodeBitmapHeapscan.c
+++ b/src/backend/executor/nodeBitmapHeapscan.c
@@ -449,6 +449,8 @@ ExecBitmapHeapScan(BitmapHeapScanState *node)
 void
 ExecReScanBitmapHeapScan(BitmapHeapScanState *node)
 {
+	PlanState	*outerPlan;
+
 	/* rescan to release any page pin */
 	heap_rescan(node->ss.ss_currentScanDesc, NULL);
 
@@ -469,8 +471,9 @@ ExecReScanBitmapHeapScan(BitmapHeapScanState *node)
 	 * if chgParam of subnode is not null then plan will be re-scanned by
 	 * first ExecProcNode.
 	 */
-	if (node->ss.ps.lefttree->chgParam == NULL)
-		ExecReScan(node->ss.ps.lefttree);
+	outerPlan = outerPlanState(node);
+	if (outerPlan->chgParam == NULL)
+		ExecReScan(outerPlan);
 }
 
 /* ----------------------------------------------------------------
diff --git a/src/backend/executor/nodeGroup.c b/src/backend/executor/nodeGroup.c
old mode 100644
new mode 100755
index 83d562e..b0d5442
--- a/src/backend/executor/nodeGroup.c
+++ b/src/backend/executor/nodeGroup.c
@@ -280,6 +280,8 @@ ExecEndGroup(GroupState *node)
 void
 ExecReScanGroup(GroupState *node)
 {
+	PlanState	*outerPlan;
+	
 	node->grp_done = FALSE;
 	node->ss.ps.ps_TupFromTlist = false;
 	/* must clear first tuple */
@@ -289,7 +291,7 @@ ExecReScanGroup(GroupState *node)
 	 * if chgParam of subnode is not null then plan will be re-scanned by
 	 * first ExecProcNode.
 	 */
-	if (node->ss.ps.lefttree &&
-		node->ss.ps.lefttree->chgParam == NULL)
-		ExecReScan(node->ss.ps.lefttree);
+	outerPlan = outerPlanState(node);
+	if (outerPlan->chgParam == NULL)
+		ExecReScan(outerPlan);
 }
diff --git a/src/backend/executor/nodeMaterial.c b/src/backend/executor/nodeMaterial.c
old mode 100644
new mode 100755
index 1158825..8ff4352
--- a/src/backend/executor/nodeMaterial.c
+++ b/src/backend/executor/nodeMaterial.c
@@ -317,6 +317,8 @@ ExecMaterialRestrPos(MaterialState *node)
 void
 ExecReScanMaterial(MaterialState *node)
 {
+	PlanState	*outerPlan = outerPlanState(node);
+
 	ExecClearTuple(node->ss.ps.ps_ResultTupleSlot);
 
 	if (node->eflags != 0)
@@ -339,13 +341,13 @@ ExecReScanMaterial(MaterialState *node)
 		 * Otherwise we can just rewind and rescan the stored output. The
 		 * state of the subnode does not change.
 		 */
-		if (node->ss.ps.lefttree->chgParam != NULL ||
+		if (outerPlan->chgParam != NULL ||
 			(node->eflags & EXEC_FLAG_REWIND) == 0)
 		{
 			tuplestore_end(node->tuplestorestate);
 			node->tuplestorestate = NULL;
-			if (node->ss.ps.lefttree->chgParam == NULL)
-				ExecReScan(node->ss.ps.lefttree);
+			if (outerPlan->chgParam == NULL)
+				ExecReScan(outerPlan);
 			node->eof_underlying = false;
 		}
 		else
@@ -359,8 +361,8 @@ ExecReScanMaterial(MaterialState *node)
 		 * if chgParam of subnode is not null then plan will be re-scanned by
 		 * first ExecProcNode.
 		 */
-		if (node->ss.ps.lefttree->chgParam == NULL)
-			ExecReScan(node->ss.ps.lefttree);
+		if (outerPlan->chgParam == NULL)
+			ExecReScan(outerPlan);
 		node->eof_underlying = false;
 	}
 }
diff --git a/src/backend/executor/nodeSort.c b/src/backend/executor/nodeSort.c
old mode 100644
new mode 100755
index a815cde..8bdffe7
--- a/src/backend/executor/nodeSort.c
+++ b/src/backend/executor/nodeSort.c
@@ -290,6 +290,8 @@ ExecSortRestrPos(SortState *node)
 void
 ExecReScanSort(SortState *node)
 {
+	PlanState	*outerPlan = outerPlanState(node);
+	
 	/*
 	 * If we haven't sorted yet, just return. If outerplan's chgParam is not
 	 * NULL then it will be re-scanned by ExecProcNode, else no reason to
@@ -308,7 +310,7 @@ ExecReScanSort(SortState *node)
 	 *
 	 * Otherwise we can just rewind and rescan the sorted output.
 	 */
-	if (node->ss.ps.lefttree->chgParam != NULL ||
+	if (outerPlan->chgParam != NULL ||
 		node->bounded != node->bounded_Done ||
 		node->bound != node->bound_Done ||
 		!node->randomAccess)
@@ -321,8 +323,8 @@ ExecReScanSort(SortState *node)
 		 * if chgParam of subnode is not null then plan will be re-scanned by
 		 * first ExecProcNode.
 		 */
-		if (node->ss.ps.lefttree->chgParam == NULL)
-			ExecReScan(node->ss.ps.lefttree);
+		if (outerPlan->chgParam == NULL)
+			ExecReScan(outerPlan);
 	}
 	else
 		tuplesort_rescan((Tuplesortstate *) node->tuplesortstate);
diff --git a/src/backend/executor/nodeWindowAgg.c b/src/backend/executor/nodeWindowAgg.c
index a06790d..520be66 100644
--- a/src/backend/executor/nodeWindowAgg.c
+++ b/src/backend/executor/nodeWindowAgg.c
@@ -2057,6 +2057,7 @@ ExecEndWindowAgg(WindowAggState *node)
 void
 ExecReScanWindowAgg(WindowAggState *node)
 {
+	PlanState	*outerPlan;
 	ExprContext *econtext = node->ss.ps.ps_ExprContext;
 
 	node->all_done = false;
@@ -2082,8 +2083,9 @@ ExecReScanWindowAgg(WindowAggState *node)
 	 * if chgParam of subnode is not null then plan will be re-scanned by
 	 * first ExecProcNode.
 	 */
-	if (node->ss.ps.lefttree->chgParam == NULL)
-		ExecReScan(node->ss.ps.lefttree);
+	outerPlan = outerPlanState(node);
+	if (outerPlan->chgParam == NULL)
+		ExecReScan(outerPlan);
 }
 
 /*