diff --git a/src/common/src/tdataformat.c b/src/common/src/tdataformat.c
index 0082c11e4b86066169041c7f14b55c76f75694d4..c3615e64fc249bbe0e51e54ed09c801d2a940874 100644
--- a/src/common/src/tdataformat.c
+++ b/src/common/src/tdataformat.c
@@ -248,10 +248,9 @@ void dataColAppendVal(SDataCol *pCol, const void *value, int numOfRows, int maxP
     if (numOfRows > 0) {
       // Find the first not null value, fill all previouse values as NULL
       dataColSetNEleNull(pCol, numOfRows, maxPoints);
-    } else {
-      tdAllocMemForCol(pCol, maxPoints);
     }
   }
+  tdAllocMemForCol(pCol, maxPoints);
 
   if (IS_VAR_DATA_TYPE(pCol->type)) {
     // set offset