diff --git a/src/client/src/tscServer.c b/src/client/src/tscServer.c
index 966eee6b01..257a5b2b54 100644
--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@@ -486,9 +486,11 @@ int tscBuildFetchMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
     assert(pVgroupInfo->vgroups[vgIndex].vgId > 0 && vgIndex < pTableMetaInfo->vgroupList->numOfVgroups);
 
     pRetrieveMsg->header.vgId = htonl(pVgroupInfo->vgroups[vgIndex].vgId);
+    tscDebug("%p build fetch msg from vgId:%d, vgIndex:%d", pSql, pVgroupInfo->vgroups[vgIndex].vgId, vgIndex);
   } else {
     STableMeta* pTableMeta = pTableMetaInfo->pTableMeta;
     pRetrieveMsg->header.vgId = htonl(pTableMeta->vgroupInfo.vgId);
+    tscDebug("%p build fetch msg from only one vgroup, vgId:%d", pSql, pTableMeta->vgroupInfo.vgId);
   }
 
   pSql->cmd.payloadLen = sizeof(SRetrieveTableMsg);
diff --git a/src/client/src/tscSubquery.c b/src/client/src/tscSubquery.c
index de63465e0c..4ba35a98f7 100644
--- a/src/client/src/tscSubquery.c
+++ b/src/client/src/tscSubquery.c
@@ -474,10 +474,11 @@ static void issueTSCompQuery(SSqlObj* pSql, SJoinSupporter* pSupporter, SSqlObj*
   SSqlCmd* pCmd = &pSql->cmd;
   tscClearSubqueryInfo(pCmd);
   tscFreeSqlResult(pSql);
-  
+
   SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, 0);
+  assert(pQueryInfo->numOfTables == 1);
+
   STableMetaInfo* pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
-  
   tscInitQueryInfo(pQueryInfo);
 
   TSDB_QUERY_CLEAR_TYPE(pQueryInfo->type, TSDB_QUERY_TYPE_TAG_FILTER_QUERY);