diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index bb103f23c6718c40ab9933c7ed84a73f3edb70fa..ffb2927cbdbd15023572912551dfcf3646b1e60e 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -6101,8 +6101,10 @@ void tscPrintSelectClause(SSqlObj* pSql, int32_t subClauseIndex) {
     int32_t tmpLen = 0;
     tmpLen =
         sprintf(tmpBuf, "%s(uid:%" PRId64 ", %d)", aAggs[pExpr->functionId].aName, pExpr->uid, pExpr->colInfo.colId);
+
     if (tmpLen + offset >= totalBufSize - 1) break;
 
+
     offset += sprintf(str + offset, "%s", tmpBuf);
 
     if (i < size - 1) {
@@ -6112,6 +6114,7 @@ void tscPrintSelectClause(SSqlObj* pSql, int32_t subClauseIndex) {
 
   assert(offset < totalBufSize);
   str[offset] = ']';
+  assert(offset < totalBufSize);
   tscDebug("%p select clause:%s", pSql, str);
 }
 
diff --git a/src/common/src/tvariant.c b/src/common/src/tvariant.c
index fdfa933cdeb2be89c20a5e617c082ff28378701f..09c5c761637ee40ea22fc899d517389594c2c98d 100644
--- a/src/common/src/tvariant.c
+++ b/src/common/src/tvariant.c
@@ -399,6 +399,7 @@ static int32_t toNchar(tVariant *pVariant, char **pDest, int32_t *pDestSize) {
     pVariant->wpz = (wchar_t *)tmp;
   } else {
     int32_t output = 0;
+
     bool ret = taosMbsToUcs4(pDst, nLen, *pDest, (nLen + 1) * TSDB_NCHAR_SIZE, &output);
     if (!ret) {
       return -1;
diff --git a/src/query/src/qExecutor.c b/src/query/src/qExecutor.c
index 261ba86bdae44eaf4c6ecb2e678ca1b6af99d33c..4978a27d4f415a95f70b60aa2fd1b419a786c2b8 100644
--- a/src/query/src/qExecutor.c
+++ b/src/query/src/qExecutor.c
@@ -3168,6 +3168,10 @@ void copyResToQueryResultBuf(SQInfo *pQInfo, SQuery *pQuery) {
   // all results in current group have been returned to client, try next group
   if (pGroupResInfo->index >= taosArrayGetSize(pGroupResInfo->pRows)) {
     // current results of group has been sent to client, try next group
+    pGroupResInfo->index = 0;
+    pGroupResInfo->rowId = 0;
+    taosArrayClear(pGroupResInfo->pRows);
+
     if (mergeGroupResult(pQInfo) != TSDB_CODE_SUCCESS) {
       return;  // failed to save data in the disk
     }