diff --git a/src/common/backend/catalog/index.cpp b/src/common/backend/catalog/index.cpp
index 7e99bbf96..415c9a0ee 100644
--- a/src/common/backend/catalog/index.cpp
+++ b/src/common/backend/catalog/index.cpp
@@ -6590,10 +6590,8 @@ void ScanPartitionInsertIndex(Relation partTableRel, Relation partRel, const Lis
     ListCell* cell = NULL;
     ListCell* cell1 = NULL;
     EState* estate = NULL;
-    TupleDesc tupleDesc = NULL;
     TupleTableSlot* slot = NULL;
 
-    tupleDesc = partRel->rd_att;
 
     if (PointerIsValid(indexRelList)) {
         estate = CreateExecutorState();
@@ -6614,8 +6612,9 @@ void ScanPartitionInsertIndex(Relation partTableRel, Relation partRel, const Lis
             Relation indexRel = (Relation)lfirst(cell);
             IndexInfo* indexInfo = static_cast<IndexInfo*>(lfirst(cell1));
 
-            Datum values[tupleDesc->natts];
-            bool isNull[tupleDesc->natts];
+            Datum values[INDEX_MAX_KEYS];
+            bool isNull[INDEX_MAX_KEYS];
+
             bool estateIsNotNull = false;
             ItemPointer t_ctid = tableam_tops_get_t_self(partTableRel, tuple);