diff --git a/source/libs/executor/src/scanoperator.c b/source/libs/executor/src/scanoperator.c
index 29990f2d069a4ff6999d54c6d0b466991dc1660b..ea834e90caeb931119f38f36b5629aa0d1fa4fba 100644
--- a/source/libs/executor/src/scanoperator.c
+++ b/source/libs/executor/src/scanoperator.c
@@ -484,7 +484,7 @@ int32_t addTagPseudoColumnData(SReadHandle* pHandle, const SExprInfo* pExpr, int
   int32_t code = 0;
 
   // backup the rows
-  int32_t backupRows = pBlock->info.rows;
+  int32_t backupRows = (rows == 1) ? rows : pBlock->info.rows;
   pBlock->info.rows = rows;
 
   bool            freeReader = false;