diff --git a/src/query/src/qExecutor.c b/src/query/src/qExecutor.c
index d48d7d5ea1..6b67c7ceb9 100644
--- a/src/query/src/qExecutor.c
+++ b/src/query/src/qExecutor.c
@@ -1951,36 +1951,36 @@ static void changeExecuteScanOrder(SQInfo *pQInfo, SQueryTableMsg* pQueryMsg, bo
 
   // todo handle the case the the order irrelevant query type mixed up with order critical query type
   // descending order query for last_row query
-  if (isFirstLastRowQuery(pQuery) && !QUERY_IS_ASC_QUERY(pQuery)) {
+  if (isFirstLastRowQuery(pQuery)) {
     qDebug("QInfo:%p scan order changed for last_row query, old:%d, new:%d", GET_QINFO_ADDR(pQuery),
            pQuery->order.order, TSDB_ORDER_ASC);
 
-    SWAP(pQuery->window.skey, pQuery->window.ekey, TSKEY);
     pQuery->order.order = TSDB_ORDER_ASC;
-    assert (pQuery->window.skey <= pQuery->window.ekey);
+    if (pQuery->window.skey > pQuery->window.ekey) {
+      SWAP(pQuery->window.skey, pQuery->window.ekey, TSKEY);
+    }
+
+    return;
+  }
+
+  if (isGroupbyNormalCol(pQuery->pGroupbyExpr) && pQuery->order.order == TSDB_ORDER_DESC) {
+    pQuery->order.order = TSDB_ORDER_ASC;
+    if (pQuery->window.skey > pQuery->window.ekey) {
+      SWAP(pQuery->window.skey, pQuery->window.ekey, TSKEY);
+    }
 
     doExchangeTimeWindow(pQInfo, &pQuery->window);
     return;
   }
 
-  if (isGroupbyNormalCol(pQuery->pGroupbyExpr) && !QUERY_IS_ASC_QUERY(pQuery)) {
-    pQuery->order.order = TSDB_ORDER_ASC;
-    SWAP(pQuery->window.skey, pQuery->window.ekey, TSKEY);
-    assert (pQuery->window.skey <= pQuery->window.ekey);
-
-    doExchangeTimeWindow(pQInfo, &pQuery->window);
-    return;
-  }
-
-  if (isPointInterpoQuery(pQuery) && (pQuery->intervalTime == 0) && !QUERY_IS_ASC_QUERY(pQuery)) {
-    qDebug(msg, GET_QINFO_ADDR(pQuery), "interp", pQuery->order.order, TSDB_ORDER_ASC, pQuery->window.skey,
-           pQuery->window.ekey, pQuery->window.ekey, pQuery->window.skey);
-    SWAP(pQuery->window.skey, pQuery->window.ekey, TSKEY);
+  if (isPointInterpoQuery(pQuery) && pQuery->intervalTime == 0) {
+    if (!QUERY_IS_ASC_QUERY(pQuery)) {
+      qDebug(msg, GET_QINFO_ADDR(pQuery), "interp", pQuery->order.order, TSDB_ORDER_ASC, pQuery->window.skey,
+             pQuery->window.ekey, pQuery->window.ekey, pQuery->window.skey);
+      SWAP(pQuery->window.skey, pQuery->window.ekey, TSKEY);
+    }
 
     pQuery->order.order = TSDB_ORDER_ASC;
-
-    assert (pQuery->window.skey <= pQuery->window.ekey);
-    doExchangeTimeWindow(pQInfo, &pQuery->window);
     return;
   }
 
@@ -2365,16 +2365,16 @@ static void ensureOutputBuffer(SQueryRuntimeEnv* pRuntimeEnv, SDataBlockInfo* pB
           memset(tmp + sizeof(tFilePage) + bytes * pRec->rows, 0, (size_t)((newSize - pRec->rows) * bytes));
           pQuery->sdata[i] = (tFilePage *)tmp;
         }
-        
+
         // set the pCtx output buffer position
         pRuntimeEnv->pCtx[i].aOutputBuf = pQuery->sdata[i]->data + pRec->rows * bytes;
-        
+
         int32_t functionId = pQuery->pSelectExpr[i].base.functionId;
         if (functionId == TSDB_FUNC_TOP || functionId == TSDB_FUNC_BOTTOM || functionId == TSDB_FUNC_DIFF) {
           pRuntimeEnv->pCtx[i].ptsOutputBuf = pRuntimeEnv->pCtx[0].aOutputBuf;
         }
       }
-      
+
       qDebug("QInfo:%p realloc output buffer, new size: %d rows, old:%" PRId64 ", remain:%" PRId64, GET_QINFO_ADDR(pRuntimeEnv),
              newSize, pRec->capacity, newSize - pRec->rows);
 
@@ -2920,11 +2920,11 @@ int32_t mergeIntoGroupResultImpl(SQInfo *pQInfo, SArray *pGroup) {
     STableQueryInfo *item = taosArrayGetP(pGroup, i);
 
     SIDList list = getDataBufPagesIdList(pRuntimeEnv->pResultBuf, TSDB_TABLEID(item->pTable)->tid);
+    pageList = list;
+    tid = TSDB_TABLEID(item->pTable)->tid;
 
     if (taosArrayGetSize(list) > 0 && item->windowResInfo.size > 0) {
       pTableList[numOfTables++] = item;
-      tid = TSDB_TABLEID(item->pTable)->tid;
-      pageList = list;
     }
   }
 
@@ -3357,7 +3357,7 @@ void skipResults(SQueryRuntimeEnv *pRuntimeEnv) {
     for (int32_t i = 0; i < pQuery->numOfOutput; ++i) {
       int32_t functionId = pQuery->pSelectExpr[i].base.functionId;
       int32_t bytes = pRuntimeEnv->pCtx[i].outputBytes;
-      
+
       memmove(pQuery->sdata[i]->data, (char*)pQuery->sdata[i]->data + bytes * numOfSkip, (size_t)(pQuery->rec.rows * bytes));
       pRuntimeEnv->pCtx[i].aOutputBuf = ((char*) pQuery->sdata[i]->data) + pQuery->rec.rows * bytes;
 
@@ -4354,32 +4354,6 @@ static bool skipTimeInterval(SQueryRuntimeEnv *pRuntimeEnv, TSKEY* start) {
   return true;
 }
 
-static void freeTableQueryInfo(STableGroupInfo* pTableGroupInfo) {
-  if (pTableGroupInfo->pGroupList == NULL) {
-    assert(pTableGroupInfo->numOfTables == 0);
-  } else {
-    size_t numOfGroups = taosArrayGetSize(pTableGroupInfo->pGroupList);
-    for (int32_t i = 0; i < numOfGroups; ++i) {
-      SArray *p = taosArrayGetP(pTableGroupInfo->pGroupList, i);
-
-      size_t num = taosArrayGetSize(p);
-      for(int32_t j = 0; j < num; ++j) {
-        STableQueryInfo* item = taosArrayGetP(p, j);
-        destroyTableQueryInfo(item);
-      }
-
-      taosArrayDestroy(p);
-    }
-
-    taosArrayDestroy(pTableGroupInfo->pGroupList);
-    pTableGroupInfo->pGroupList = NULL;
-    pTableGroupInfo->numOfTables = 0;
-  }
-
-  taosHashCleanup(pTableGroupInfo->map);
-  pTableGroupInfo->map = NULL;
-}
-
 static int32_t setupQueryHandle(void* tsdb, SQInfo* pQInfo, bool isSTableQuery) {
   SQueryRuntimeEnv *pRuntimeEnv = &pQInfo->runtimeEnv;
   SQuery *pQuery = pQInfo->runtimeEnv.pQuery;
@@ -4415,22 +4389,20 @@ static int32_t setupQueryHandle(void* tsdb, SQInfo* pQInfo, bool isSTableQuery)
   terrno = TSDB_CODE_SUCCESS;
   if (isFirstLastRowQuery(pQuery)) {
     pRuntimeEnv->pQueryHandle = tsdbQueryLastRow(tsdb, &cond, &pQInfo->tableGroupInfo, pQInfo);
-    if (pRuntimeEnv->pQueryHandle == NULL) {  // no data in current stable, clear all
-      freeTableQueryInfo(&pQInfo->tableqinfoGroupInfo);
-    } else { // update the query time window
-      pQuery->window = cond.twindow;
 
-      size_t numOfGroups = GET_NUM_OF_TABLEGROUP(pQInfo);
-      for (int32_t i = 0; i < numOfGroups; ++i) {
-        SArray *group = GET_TABLEGROUP(pQInfo, i);
+    // update the query time window
+    pQuery->window = cond.twindow;
 
-        size_t t = taosArrayGetSize(group);
-        for (int32_t j = 0; j < t; ++j) {
-          STableQueryInfo *pCheckInfo = taosArrayGetP(group, j);
+    size_t numOfGroups = GET_NUM_OF_TABLEGROUP(pQInfo);
+    for(int32_t i = 0; i < numOfGroups; ++i) {
+      SArray *group = GET_TABLEGROUP(pQInfo, i);
 
-          pCheckInfo->win = pQuery->window;
-          pCheckInfo->lastKey = pCheckInfo->win.skey;
-        }
+      size_t t = taosArrayGetSize(group);
+      for (int32_t j = 0; j < t; ++j) {
+        STableQueryInfo *pCheckInfo = taosArrayGetP(group, j);
+
+        pCheckInfo->win = pQuery->window;
+        pCheckInfo->lastKey = pCheckInfo->win.skey;
       }
     }
   } else if (isPointInterpoQuery(pQuery)) {
@@ -4484,12 +4456,6 @@ int32_t doInitQInfo(SQInfo *pQInfo, STSBuf *pTsBuf, void *tsdb, int32_t vgId, bo
     return code;
   }
 
-  if (pQInfo->tableqinfoGroupInfo.numOfTables == 0) {
-    qDebug("QInfo:%p no table qualified for tag filter, abort query", pQInfo);
-    setQueryStatus(pQuery, QUERY_COMPLETED);
-    return TSDB_CODE_SUCCESS;
-  }
-
   pQInfo->tsdb = tsdb;
   pQInfo->vgId = vgId;
 
@@ -4612,7 +4578,7 @@ static int64_t scanMultiTableDataBlocks(SQInfo *pQInfo) {
   SQueryRuntimeEnv *pRuntimeEnv = &pQInfo->runtimeEnv;
   SQuery*           pQuery = pRuntimeEnv->pQuery;
   SQueryCostInfo*   summary  = &pRuntimeEnv->summary;
-  
+
   int64_t st = taosGetTimestampMs();
 
   TsdbQueryHandleT pQueryHandle = IS_MASTER_SCAN(pRuntimeEnv)? pRuntimeEnv->pQueryHandle : pRuntimeEnv->pSecQueryHandle;
@@ -4622,7 +4588,7 @@ static int64_t scanMultiTableDataBlocks(SQInfo *pQInfo) {
 
   while (tsdbNextDataBlock(pQueryHandle)) {
     summary->totalBlocks += 1;
-    
+
     if (IS_QUERY_KILLED(pQInfo)) {
       longjmp(pRuntimeEnv->env, TSDB_CODE_TSC_QUERY_CANCELLED);
     }
@@ -4659,7 +4625,7 @@ static int64_t scanMultiTableDataBlocks(SQInfo *pQInfo) {
 
     summary->totalRows += blockInfo.rows;
     stableApplyFunctionsOnBlock(pRuntimeEnv, &blockInfo, pStatis, pDataBlock, binarySearchForKey);
-  
+
     qDebug("QInfo:%p check data block completed, uid:%"PRId64", tid:%d, brange:%" PRId64 "-%" PRId64 ", numOfRows:%d, "
            "lastKey:%" PRId64,
            pQInfo, blockInfo.uid, blockInfo.tid, blockInfo.window.skey, blockInfo.window.ekey, blockInfo.rows,
@@ -6383,10 +6349,25 @@ static void freeQInfo(SQInfo *pQInfo) {
     taosTFree(pQuery);
   }
 
-  freeTableQueryInfo(&pQInfo->tableqinfoGroupInfo);
+  // todo refactor, extract method to destroytableDataInfo
+  if (pQInfo->tableqinfoGroupInfo.pGroupList != NULL) {
+    int32_t numOfGroups = (int32_t)(GET_NUM_OF_TABLEGROUP(pQInfo));
+    for (int32_t i = 0; i < numOfGroups; ++i) {
+      SArray *p = GET_TABLEGROUP(pQInfo, i);
+
+      size_t num = taosArrayGetSize(p);
+      for(int32_t j = 0; j < num; ++j) {
+        STableQueryInfo* item = taosArrayGetP(p, j);
+        destroyTableQueryInfo(item);
+      }
+
+      taosArrayDestroy(p);
+    }
+  }
 
   taosTFree(pQInfo->pBuf);
-
+  taosArrayDestroy(pQInfo->tableqinfoGroupInfo.pGroupList);
+  taosHashCleanup(pQInfo->tableqinfoGroupInfo.map);
   tsdbDestroyTableGroup(&pQInfo->tableGroupInfo);
   taosArrayDestroy(pQInfo->arrTableIdInfo);