diff --git a/src/backend/executor/nodeIncrementalSort.c b/src/backend/executor/nodeIncrementalSort.c
index 34257ce34b..655b1c30e1 100644
--- a/src/backend/executor/nodeIncrementalSort.c
+++ b/src/backend/executor/nodeIncrementalSort.c
@@ -166,6 +166,9 @@ preparePresortedCols(IncrementalSortState *node)
 {
 	IncrementalSort *plannode = castNode(IncrementalSort, node->ss.ps.plan);
 
+	if (node->presorted_keys)
+		return;
+
 	node->presorted_keys =
 		(PresortedKeyData *) palloc(plannode->nPresortedCols *
 									sizeof(PresortedKeyData));
@@ -1140,7 +1143,6 @@ ExecReScanIncrementalSort(IncrementalSortState *node)
 	node->outerNodeDone = false;
 	node->n_fullsort_remaining = 0;
 	node->bound_Done = 0;
-	node->presorted_keys = NULL;
 
 	node->execution_status = INCSORT_LOADFULLSORT;
 
@@ -1154,12 +1156,12 @@ ExecReScanIncrementalSort(IncrementalSortState *node)
 	 */
 	if (node->fullsort_state != NULL)
 	{
-		tuplesort_reset(node->fullsort_state);
+		tuplesort_end(node->fullsort_state);
 		node->fullsort_state = NULL;
 	}
 	if (node->prefixsort_state != NULL)
 	{
-		tuplesort_reset(node->prefixsort_state);
+		tuplesort_end(node->prefixsort_state);
 		node->prefixsort_state = NULL;
 	}