diff --git a/internal/proto/query_coord.proto b/internal/proto/query_coord.proto
index b584bcf600..b7b337a5a9 100644
--- a/internal/proto/query_coord.proto
+++ b/internal/proto/query_coord.proto
@@ -52,6 +52,7 @@ service QueryNode {
 //--------------------query coordinator proto------------------
 message ShowCollectionsRequest {
   common.MsgBase base = 1;
+  // Not useful for now
   int64 dbID = 2;
   repeated int64 collectionIDs = 3;
 }