diff --git a/internal/querynode/flow_graph_insert_node.go b/internal/querynode/flow_graph_insert_node.go
index 8c108c3230..bb1f7bf4ae 100644
--- a/internal/querynode/flow_graph_insert_node.go
+++ b/internal/querynode/flow_graph_insert_node.go
@@ -51,6 +51,7 @@ type insertData struct {
 	insertPKs        map[UniqueID][]int64
 }
 
+// deleteData stores the valid delete data
 type deleteData struct {
 	deleteIDs        map[UniqueID][]int64
 	deleteTimestamps map[UniqueID][]Timestamp