diff --git a/src/query/src/qExecutor.c b/src/query/src/qExecutor.c
index 9b356d57b81d56ad1db2df3a7806c0e7ccbbac59..97a6cf807cce0c6b57fc6e8598331769ae22f896 100644
--- a/src/query/src/qExecutor.c
+++ b/src/query/src/qExecutor.c
@@ -1306,7 +1306,8 @@ static void doHashGroupbyAgg(SOperatorInfo* pOperator, SGroupbyOperatorInfo *pIn
     }
 
     if (IS_VAR_DATA_TYPE(type)) {
-      if(varDataLen(val) == varDataLen(pInfo->prevData) && memcmp(varDataVal(pInfo->prevData), varDataVal(val), varDataLen(val)) == 0) {
+      int32_t len = varDataLen(val);
+      if(len == varDataLen(pInfo->prevData) && memcmp(varDataVal(pInfo->prevData), varDataVal(val), len) == 0) {
         num++;
         continue;
       }