diff --git a/src/client/src/tscSql.c b/src/client/src/tscSql.c
index 1150bd479e3b104c359c31aa63c70f3e433cd2d2..f33e589c82164ca2b09a63b478d83c66bc58e37d 100644
--- a/src/client/src/tscSql.c
+++ b/src/client/src/tscSql.c
@@ -793,7 +793,7 @@ void taos_free_result_imp(TAOS_RES *res, int keepCmd) {
    *         be executed, and the retry efforts may result in double free the resources, e.g.,SRetrieveSupport
    */
   if (pRes->code != TSDB_CODE_QUERY_CANCELLED &&
-      ((pRes->numOfRows > 0 && pCmd->command < TSDB_SQL_LOCAL) ||
+      ((pRes->numOfRows > 0 && pCmd->command < TSDB_SQL_LOCAL && pRes->completed == false) ||
        (pRes->code == TSDB_CODE_SUCCESS && pRes->numOfRows == 0 && pCmd->command == TSDB_SQL_SELECT &&
         pSql->pStream == NULL && pTableMetaInfo->pTableMeta != NULL))) {
     pCmd->command = (pCmd->command > TSDB_SQL_MGMT) ? TSDB_SQL_RETRIEVE : TSDB_SQL_FETCH;
diff --git a/src/query/src/queryExecutor.c b/src/query/src/queryExecutor.c
index 75823c4e2e95f5cfc1d458ceece7d2b4acb2d193..932c04337745fb4e36cc2b04a4b6829703f4e6ed 100644
--- a/src/query/src/queryExecutor.c
+++ b/src/query/src/queryExecutor.c
@@ -5148,7 +5148,7 @@ static void singleTableQueryImpl(SQInfo* pQInfo) {
   int64_t st = taosGetTimestampUs();
   
   // group by normal column, sliding window query, interval query are handled by interval query processor
-  if (pQuery->intervalTime != 0 || isGroupbyNormalCol(pQuery->pGroupbyExpr)) {  // interval (down sampling operation)
+  if (isIntervalQuery(pQuery) || isGroupbyNormalCol(pQuery->pGroupbyExpr)) {  // interval (down sampling operation)
     tableIntervalProcessor(pQInfo);
   } else {
     if (isFixedOutputQuery(pQuery)) {
diff --git a/src/vnode/tsdb/src/tsdbFile.c b/src/vnode/tsdb/src/tsdbFile.c
index ff8da1cdadd130dc28b6544f58620a50429c5643..bd6699eb8484b3ee9b1bbb9cb2415f10f1d7b8f3 100644
--- a/src/vnode/tsdb/src/tsdbFile.c
+++ b/src/vnode/tsdb/src/tsdbFile.c
@@ -147,6 +147,11 @@ void tsdbInitFileGroupIter(STsdbFileH *pFileH, SFileGroupIter *pIter, int direct
 }
 
 void tsdbSeekFileGroupIter(SFileGroupIter *pIter, int fid) {
+  if (pIter->numOfFGroups == 0) {
+    assert(pIter->pFileGroup == NULL);
+    return;
+  }
+  
   int flags = (pIter->direction == TSDB_FGROUP_ITER_FORWARD) ? TD_GE : TD_LE;
   void *ptr = taosbsearch(&fid, pIter->base, sizeof(SFileGroup), pIter->numOfFGroups, compFGroupKey, flags);
   if (ptr == NULL) {
diff --git a/src/vnode/tsdb/src/tsdbRead.c b/src/vnode/tsdb/src/tsdbRead.c
index c134ba257a7b252d56995d6ef5be44dc01120b87..599d8bd34738d047f2e3331d3a242f08976bf7b9 100644
--- a/src/vnode/tsdb/src/tsdbRead.c
+++ b/src/vnode/tsdb/src/tsdbRead.c
@@ -745,12 +745,23 @@ static bool getQualifiedDataBlock(STsdbQueryHandle *pQueryHandle, STableCheckInf
   int32_t index = -1;
 
   int32_t tid = pCheckInfo->tableId.tid;
-  SFile* pFile = &pCheckInfo->pFileGroup->files[TSDB_FILE_TYPE_DATA];
   
-  while (1) {
+  while (pCheckInfo->pFileGroup != NULL) {
     if ((fid = getFileCompInfo(pCheckInfo, pCheckInfo->pFileGroup)) < 0) {
       break;
     }
+  
+    SFile* pFile = &pCheckInfo->pFileGroup->files[TSDB_FILE_TYPE_DATA];
+  
+    // no data block in current file, try next
+    if (pCheckInfo->compIndex[tid].numOfSuperBlocks == 0) {
+      dTrace("QInfo:%p no data block in file, fid:%d, tid:%d, try next", pQueryHandle->qinfo,
+          pCheckInfo->pFileGroup->fileId, tid);
+      
+      pCheckInfo->pFileGroup = tsdbGetFileGroupNext(&pCheckInfo->fileIter);
+  
+      continue;
+    }
     
     index = binarySearchForBlockImpl(pCheckInfo->pCompInfo->blocks, pCheckInfo->compIndex[tid].numOfSuperBlocks, pQueryHandle->order, key);
     
@@ -792,6 +803,7 @@ static bool getQualifiedDataBlock(STsdbQueryHandle *pQueryHandle, STableCheckInf
   pCheckInfo->pDataCols = tdNewDataCols(1000, 2, 4096);
   tdInitDataCols(pCheckInfo->pDataCols, pCheckInfo->pTableObj->schema);
   
+  SFile* pFile = &pCheckInfo->pFileGroup->files[TSDB_FILE_TYPE_DATA];
   if (pFile->fd == FD_INITIALIZER) {
     pFile->fd = open(pFile->fname, O_RDONLY);
   }