diff --git a/src/query/src/qFilter.c b/src/query/src/qFilter.c
index 94a2f6c3cf4d5640958e0b747f9edbe0b57e1e15..d3d96fae337c34a272447868f5d10cda5f19e888 100644
--- a/src/query/src/qFilter.c
+++ b/src/query/src/qFilter.c
@@ -2102,6 +2102,7 @@ void filterCheckColConflict(SFilterGroupCtx* gRes1, SFilterGroupCtx* gRes2, bool
         continue;
       }
 
+      // for long in operation
       if (gRes1->colInfo[idx1].optr == TSDB_RELATION_EQUAL && gRes2->colInfo[idx2].optr == TSDB_RELATION_EQUAL) {
         *conflict = true;
         return;