diff --git a/src/backend/columnar/cstore_tableam.c b/src/backend/columnar/cstore_tableam.c
index 7dd143277..1178b94b4 100644
--- a/src/backend/columnar/cstore_tableam.c
+++ b/src/backend/columnar/cstore_tableam.c
@@ -87,7 +87,7 @@ typedef struct ColumnarScanDescData
 	 * ANALYZE requires an item pointer for sorting. We keep track of row
 	 * number so we can construct an item pointer based on that.
 	 */
-	int rowNumber;
+	uint64 rowNumber;
 } ColumnarScanDescData;
 
 typedef struct ColumnarScanDescData *ColumnarScanDesc;
@@ -191,7 +191,7 @@ columnar_beginscan_extended(Relation relation, Snapshot snapshot,
 
 	MemoryContext oldContext = MemoryContextSwitchTo(scanContext);
 
-	ColumnarScanDesc scan = palloc(sizeof(ColumnarScanDescData));
+	ColumnarScanDesc scan = palloc0(sizeof(ColumnarScanDescData));
 	scan->cs_base.rs_rd = relation;
 	scan->cs_base.rs_snapshot = snapshot;
 	scan->cs_base.rs_nkeys = nkeys;