diff --git a/src/client/src/tscAsync.c b/src/client/src/tscAsync.c
index d7224871dae51beefabfca6d8fba38ed547c97d2..96837e4dd47045617e50f0a0e9eeb6982f3453b5 100644
--- a/src/client/src/tscAsync.c
+++ b/src/client/src/tscAsync.c
@@ -57,6 +57,7 @@ void doAsyncQuery(STscObj* pObj, SSqlObj* pSql, void (*fp)(), void* param, const
   }
   
   pSql->sqlstr = realloc(pSql->sqlstr, sqlLen + 1);
+  
   if (pSql->sqlstr == NULL) {
     tscError("%p failed to malloc sql string buffer", pSql);
     tscQueueAsyncError(fp, param, TSDB_CODE_CLI_OUT_OF_MEMORY);
diff --git a/src/client/src/tscFunctionImpl.c b/src/client/src/tscFunctionImpl.c
index 81602d17f4560949d3cc7a9cce2e43eb6875302b..f56babca03685987cf64ca49426eb0c02b2ae646 100644
--- a/src/client/src/tscFunctionImpl.c
+++ b/src/client/src/tscFunctionImpl.c
@@ -3003,6 +3003,7 @@ static void tag_project_function_f(SQLFunctionCtx *pCtx, int32_t index) {
     output += VARSTR_HEADER_SIZE;
   }
   
+  // todo : handle the binary/nchar data
   tVariantDump(&pCtx->tag, output, pCtx->tag.nType);
   pCtx->aOutputBuf += pCtx->outputBytes;
 }
@@ -3857,10 +3858,14 @@ void twa_function_finalizer(SQLFunctionCtx *pCtx) {
  * param[2]: next value of specified timestamp
  * param[3]: denotes if the result is a precious result or interpolation results
  *
+ * param[1]: denote the specified timestamp to generated the interp result
+ * param[2]: fill policy
+ *
  * @param pCtx
  */
 static void interp_function(SQLFunctionCtx *pCtx) {
   // at this point, the value is existed, return directly
+#if 0
   if (pCtx->param[3].i64Key == 1) {
     char *pData = GET_INPUT_CHAR(pCtx);
     assignVal(pCtx->aOutputBuf, pData, pCtx->inputBytes, pCtx->inputType);
@@ -3955,6 +3960,88 @@ static void interp_function(SQLFunctionCtx *pCtx) {
   tVariantDestroy(&pCtx->param[2]);
   
   // data in the check operation are all null, not output
+  SET_VAL(pCtx, pCtx->size, 1);
+#endif
+  
+  SResultInfo *pResInfo = GET_RES_INFO(pCtx);
+  SInterpInfoDetail* pInfo = pResInfo->interResultBuf;
+
+  if (pCtx->size == 1) {
+    char *pData = GET_INPUT_CHAR(pCtx);
+    assignVal(pCtx->aOutputBuf, pData, pCtx->inputBytes, pCtx->inputType);
+  } else {
+    /*
+     * use interpolation to generate the result.
+     * Note: the result of primary timestamp column uses the timestamp specified by user in the query sql
+     */
+    assert(pCtx->size == 2);
+    if (pInfo->type == TSDB_FILL_NONE) {  // set no output result
+      return;
+    }
+    
+    if (pInfo->primaryCol == 1) {
+      *(TSKEY *) pCtx->aOutputBuf = pInfo->ts;
+    } else {
+      if (pInfo->type == TSDB_FILL_NULL) {
+        if (pCtx->outputType == TSDB_DATA_TYPE_BINARY || pCtx->outputType == TSDB_DATA_TYPE_NCHAR) {
+          setVardataNull(pCtx->aOutputBuf, pCtx->outputType);
+        } else {
+          setNull(pCtx->aOutputBuf, pCtx->outputType, pCtx->outputBytes);
+        }
+  
+        SET_VAL(pCtx, pCtx->size, 1);
+      } else if (pInfo->type == TSDB_FILL_SET_VALUE) {
+        tVariantDump(&pCtx->param[1], pCtx->aOutputBuf, pCtx->inputType);
+      } else if (pInfo->type == TSDB_FILL_PREV) {
+        char *data = GET_INPUT_CHAR_INDEX(pCtx, 0);
+        assignVal(pCtx->aOutputBuf, data, pCtx->outputBytes, pCtx->outputType);
+  
+        SET_VAL(pCtx, pCtx->size, 1);
+      } else if (pInfo->type == TSDB_FILL_LINEAR) {
+        char *data1 = GET_INPUT_CHAR_INDEX(pCtx, 0);
+        char *data2 = GET_INPUT_CHAR_INDEX(pCtx, 1);
+      
+        TSKEY key1 = pCtx->ptsList[0];
+        TSKEY key2 = pCtx->ptsList[1];
+      
+        SPoint point1 = {.key = key1, .val = data1};
+        SPoint point2 = {.key = key2, .val = data2};
+      
+        SPoint point = {.key = pInfo->ts, .val = pCtx->aOutputBuf};
+      
+        int32_t srcType = pCtx->inputType;
+        if ((srcType >= TSDB_DATA_TYPE_TINYINT && srcType <= TSDB_DATA_TYPE_BIGINT) ||
+            srcType == TSDB_DATA_TYPE_TIMESTAMP || srcType == TSDB_DATA_TYPE_DOUBLE) {
+          point1.val = data1;
+          point2.val = data2;
+        
+          if (isNull(data1, srcType) || isNull(data2, srcType)) {
+            setNull(pCtx->aOutputBuf, srcType, pCtx->inputBytes);
+          } else {
+            taosDoLinearInterpolation(pCtx->outputType, &point1, &point2, &point);
+          }
+        } else if (srcType == TSDB_DATA_TYPE_FLOAT) {
+          point1.val = data1;
+          point2.val = data2;
+        
+          if (isNull(data1, srcType) || isNull(data2, srcType)) {
+            setNull(pCtx->aOutputBuf, srcType, pCtx->inputBytes);
+          } else {
+            taosDoLinearInterpolation(pCtx->outputType, &point1, &point2, &point);
+          }
+        
+        } else {
+          if (srcType == TSDB_DATA_TYPE_BINARY || srcType == TSDB_DATA_TYPE_NCHAR) {
+            setVardataNull(pCtx->aOutputBuf, pCtx->inputType);
+          } else {
+            setNull(pCtx->aOutputBuf, srcType, pCtx->inputBytes);
+          }
+        }
+      }
+    }
+    
+  }
+  
   SET_VAL(pCtx, pCtx->size, 1);
 }
 
@@ -4910,7 +4997,7 @@ SQLAggFuncElem aAggs[] = {{
                               "interp",
                               TSDB_FUNC_INTERP,
                               TSDB_FUNC_INTERP,
-                              TSDB_FUNCSTATE_SO | TSDB_FUNCSTATE_OF | TSDB_FUNCSTATE_STABLE | TSDB_FUNCSTATE_NEED_TS,
+                              TSDB_FUNCSTATE_SO | TSDB_FUNCSTATE_OF | TSDB_FUNCSTATE_STABLE | TSDB_FUNCSTATE_NEED_TS ,
                               function_setup,
                               interp_function,
                               do_sum_f,  // todo filter handle
@@ -4918,7 +5005,7 @@ SQLAggFuncElem aAggs[] = {{
                               doFinalizer,
                               noop1,
                               copy_function,
-                              no_data_info,
+                              data_req_load_info,
                           },
                           {
                               // 28
diff --git a/src/client/src/tscServer.c b/src/client/src/tscServer.c
index 7d0ac09e66c14160f4dd715f0c44cec40674549c..38e7065a9a9c8484c25a403d83fb84fed623270f 100644
--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@@ -220,7 +220,9 @@ void tscProcessMsgFromServer(SRpcMsg *rpcMsg, SRpcIpSet *pIpSet) {
   if (pSql->freed || pObj->signature != pObj) {
     tscTrace("%p sql is already released or DB connection is closed, freed:%d pObj:%p signature:%p", pSql, pSql->freed,
              pObj, pObj->signature);
-    tscFreeSqlObj(pSql);
+    if (pObj->pSql != pSql) { // it is not a main SqlObj, should be freed
+      tscFreeSqlObj(pSql);
+    }
     rpcFreeCont(rpcMsg->pCont);
     return;
   }
@@ -1867,8 +1869,8 @@ int tscProcessTableMetaRsp(SSqlObj *pSql) {
     return TSDB_CODE_CLI_OUT_OF_MEMORY;
   }
 
-  free(pTableMeta);
   tscTrace("%p recv table meta: %"PRId64 ", tid:%d, name:%s", pSql, pTableMeta->uid, pTableMeta->sid, pTableMetaInfo->name);
+  free(pTableMeta);
   
   return TSDB_CODE_SUCCESS;
 }
diff --git a/src/client/src/tscSql.c b/src/client/src/tscSql.c
index 14605a571deefbf5543de7ebc57287f6a2eedaac..66ab4aa7dd39aaa2c4151c731990c6305b45da7f 100644
--- a/src/client/src/tscSql.c
+++ b/src/client/src/tscSql.c
@@ -530,7 +530,6 @@ void taos_free_result_imp(TAOS_RES *res, int keepCmd) {
 
   SSqlObj *pSql = (SSqlObj *)res;
   SSqlRes *pRes = &pSql->res;
-  SSqlCmd *pCmd = &pSql->cmd;
 
   tscTrace("%p start to free result", pSql);
 
@@ -562,10 +561,6 @@ void taos_free_result_imp(TAOS_RES *res, int keepCmd) {
     return;
   }
 
-  pQueryInfo->type = TSDB_QUERY_TYPE_FREE_RESOURCE;
-
-  STableMetaInfo *pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
-
   /*
    * case 1. Partial data have been retrieved from vnodes, but not all data has been retrieved yet.
    *         We need to recycle the connection by noticing the vnode return 0 results.
@@ -576,27 +571,27 @@ void taos_free_result_imp(TAOS_RES *res, int keepCmd) {
    *         for each subquery. Because the failure of execution tsProcessSql may trigger the callback function
    *         be executed, and the retry efforts may result in double free the resources, e.g.,SRetrieveSupport
    */
-  if ((pCmd->command == TSDB_SQL_SELECT || pCmd->command == TSDB_SQL_SHOW || pCmd->command == TSDB_SQL_RETRIEVE ||
-      pCmd->command == TSDB_SQL_FETCH) &&
-      (pRes->code != TSDB_CODE_QUERY_CANCELLED && ((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;
-
-    tscTrace("%p code:%d, numOfRows:%d, command:%d", pSql, pRes->code, pRes->numOfRows, pCmd->command);
-
-    pSql->freed = 1;
-    tscProcessSql(pSql);
+//  if ((pCmd->command == TSDB_SQL_SELECT || pCmd->command == TSDB_SQL_SHOW || pCmd->command == TSDB_SQL_RETRIEVE ||
+//      pCmd->command == TSDB_SQL_FETCH) &&
+//      (pRes->code != TSDB_CODE_QUERY_CANCELLED && ((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;
+//
+//    tscTrace("%p code:%d, numOfRows:%d, command:%d", pSql, pRes->code, pRes->numOfRows, pCmd->command);
+//
+//    pSql->freed = 1;
+//    tscProcessSql(pSql);
 
     /*
      *  If release connection msg is sent to vnode, the corresponding SqlObj for async query can not be freed instantly,
      *  since its free operation is delegated to callback function, which is tscProcessMsgFromServer.
      */
-    STscObj* pObj = pSql->pTscObj;
-    if (pObj->pSql == pSql) {
-      pObj->pSql = NULL;
-    }
-  } else { // if no free resource msg is sent to vnode, we free this object immediately.
+//    STscObj* pObj = pSql->pTscObj;
+//    if (pObj->pSql == pSql) {
+//      pObj->pSql = NULL;
+//    }
+//  } else { // if no free resource msg is sent to vnode, we free this object immediately.
     STscObj* pTscObj = pSql->pTscObj;
     
     if (pTscObj->pSql != pSql) {
@@ -611,7 +606,7 @@ void taos_free_result_imp(TAOS_RES *res, int keepCmd) {
         tscTrace("%p sql result is freed by app", pSql);
       }
     }
-  }
+//  }
 }
 
 void taos_free_result(TAOS_RES *res) { taos_free_result_imp(res, 0); }
diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index d66203ecbee0359f8a3fb054690b59cdfebdecbc..97ce0fbe23a92df94cf78c4a67d2b463a08b5899 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -421,8 +421,9 @@ void tscFreeSqlObj(SSqlObj* pSql) {
 
   memset(pCmd->payload, 0, (size_t)pCmd->allocSize);
   tfree(pCmd->payload);
-
   pCmd->allocSize = 0;
+  
+  tfree(pSql->sqlstr);
   free(pSql);
 }
 
diff --git a/src/inc/tsdb.h b/src/inc/tsdb.h
index bee68b81f567bf0259edea33e944a4aa074ccdaa..da806061ddd43b277baa32322e6cc3259c82805f 100644
--- a/src/inc/tsdb.h
+++ b/src/inc/tsdb.h
@@ -196,6 +196,8 @@ TsdbQueryHandleT *tsdbQueryTables(TsdbRepoT *tsdb, STsdbQueryCond *pCond, STable
  */
 TsdbQueryHandleT tsdbQueryLastRow(TsdbRepoT *tsdb, STsdbQueryCond *pCond, STableGroupInfo *groupInfo);
 
+TsdbQueryHandleT tsdbQueryRowsInExternalWindow(TsdbRepoT *tsdb, STsdbQueryCond* pCond, STableGroupInfo *groupList);
+
 /**
  * move to next block if exists
  *
diff --git a/src/query/inc/tsqlfunction.h b/src/query/inc/tsqlfunction.h
index 6e591b28d2e607ec7fa9eec81e9e0eef2757491b..62b551f2f54830637f0056efd1d6b3ceabcfbb49 100644
--- a/src/query/inc/tsqlfunction.h
+++ b/src/query/inc/tsqlfunction.h
@@ -269,9 +269,6 @@ extern struct SQLAggFuncElem aAggs[];
 /* compatible check array list */
 extern int32_t funcCompatDefList[];
 
-void getStatistics(char *priData, char *data, int32_t size, int32_t numOfRow, int32_t type, int64_t *min, int64_t *max,
-                   int64_t *sum, int16_t *minIndex, int16_t *maxIndex, int32_t *numOfNull);
-
 bool top_bot_datablock_filter(SQLFunctionCtx *pCtx, int32_t functionId, char *minval, char *maxval);
 
 bool stableQueryFunctChanged(int32_t funcId);
diff --git a/src/query/src/qExecutor.c b/src/query/src/qExecutor.c
index 4b0ff36d360d15ebb6ecb567b7dacee09702815c..44788b6b9b9e7f1ea31991a9fa4e3183c3b01d2b 100644
--- a/src/query/src/qExecutor.c
+++ b/src/query/src/qExecutor.c
@@ -110,8 +110,9 @@ static void resetMergeResultBuf(SQuery *pQuery, SQLFunctionCtx *pCtx, SResultInf
 static bool functionNeedToExecute(SQueryRuntimeEnv *pRuntimeEnv, SQLFunctionCtx *pCtx, int32_t functionId);
 static void getNextTimeWindow(SQuery *pQuery, STimeWindow *pTimeWindow);
 
-static void setExecParams(SQuery *pQuery, SQLFunctionCtx *pCtx, void* pData, TSKEY *tsCol, SDataBlockInfo* pBlockInfo,
-                          int32_t functionId, SDataStatis *pStatis, bool hasNull, void *param, int32_t scanFlag);
+static void setExecParams(SQuery *pQuery, SQLFunctionCtx *pCtx, void* inputData, TSKEY *tsCol, SDataBlockInfo* pBlockInfo,
+                          SDataStatis *pStatis, void *param, int32_t colIndex);
+
 static void initCtxOutputBuf(SQueryRuntimeEnv *pRuntimeEnv);
 static void destroyTableQueryInfo(STableQueryInfo *pTableQueryInfo, int32_t numOfCols);
 static void resetCtxOutputBuf(SQueryRuntimeEnv *pRuntimeEnv);
@@ -954,16 +955,8 @@ static void blockwiseApplyFunctions(SQueryRuntimeEnv *pRuntimeEnv, SDataStatis *
   SArithmeticSupport *sasArray = calloc((size_t)pQuery->numOfOutput, sizeof(SArithmeticSupport));
   
   for (int32_t k = 0; k < pQuery->numOfOutput; ++k) {
-    int32_t functionId = pQuery->pSelectExpr[k].base.functionId;
-    int32_t colId = pQuery->pSelectExpr[k].base.colInfo.colId;
-
-    SDataStatis *tpField = NULL;
-
-    bool  hasNull = hasNullValue(pQuery, k, pDataBlockInfo->numOfCols, pStatis, &tpField);
     char *dataBlock = getDataBlock(pRuntimeEnv, &sasArray[k], k, pDataBlockInfo->rows, pDataBlock);
-
-    setExecParams(pQuery, &pCtx[k], dataBlock, primaryKeyCol, pDataBlockInfo, functionId, tpField, hasNull,
-                  &sasArray[k], colId);
+    setExecParams(pQuery, &pCtx[k], dataBlock, primaryKeyCol, pDataBlockInfo, pStatis, &sasArray[k], k);
   }
 
   int32_t step = GET_FORWARD_DIRECTION_FACTOR(pQuery->order.order);
@@ -1176,16 +1169,8 @@ static void rowwiseApplyFunctions(SQueryRuntimeEnv *pRuntimeEnv, SDataStatis *pS
   }
 
   for (int32_t k = 0; k < pQuery->numOfOutput; ++k) {
-    int32_t functionId = pQuery->pSelectExpr[k].base.functionId;
-    int32_t colId = pQuery->pSelectExpr[k].base.colInfo.colId;
-    
-    SDataStatis *pColStatis = NULL;
-
-    bool  hasNull = hasNullValue(pQuery, k, pDataBlockInfo->numOfCols, pStatis, &pColStatis);
     char *dataBlock = getDataBlock(pRuntimeEnv, &sasArray[k], k, pDataBlockInfo->rows, pDataBlock);
-
-    setExecParams(pQuery, &pCtx[k], dataBlock, primaryKeyCol, pDataBlockInfo, functionId, pColStatis, hasNull,
-                  &sasArray[k], colId);
+    setExecParams(pQuery, &pCtx[k], dataBlock, primaryKeyCol, pDataBlockInfo, pStatis, &sasArray[k], k);
   }
 
   // set the input column data
@@ -1354,11 +1339,16 @@ static int32_t tableApplyFunctionsOnBlock(SQueryRuntimeEnv *pRuntimeEnv, SDataBl
 }
 
 void setExecParams(SQuery *pQuery, SQLFunctionCtx *pCtx, void* inputData, TSKEY *tsCol, SDataBlockInfo* pBlockInfo,
-                   int32_t functionId, SDataStatis *pStatis, bool hasNull, void *param, int32_t colId) {
-  pCtx->hasNull  = hasNull;
+                   SDataStatis *pStatis, void *param, int32_t colIndex) {
+  
+  int32_t functionId = pQuery->pSelectExpr[colIndex].base.functionId;
+  int32_t colId = pQuery->pSelectExpr[colIndex].base.colInfo.colId;
+  
+  SDataStatis *tpField = NULL;
+  pCtx->hasNull = hasNullValue(pQuery, colIndex, pBlockInfo->numOfCols, pStatis, &tpField);
   pCtx->aInputElemBuf = inputData;
 
-  if (pStatis != NULL) {
+  if (tpField != NULL) {
     pCtx->preAggVals.isSet  = true;
     pCtx->preAggVals.statis = *pStatis;
     if (pCtx->preAggVals.statis.numOfNull == -1) {
@@ -1404,6 +1394,19 @@ void setExecParams(SQuery *pQuery, SQLFunctionCtx *pCtx, void* inputData, TSKEY
       pCtx->preAggVals.statis.min = pBlockInfo->window.skey;
       pCtx->preAggVals.statis.max = pBlockInfo->window.ekey;
     }
+  } else if (functionId == TSDB_FUNC_INTERP) {
+    SInterpInfoDetail *pInterpInfo = GET_RES_INFO(pCtx)->interResultBuf;
+    pInterpInfo->type = pQuery->fillType;
+    pInterpInfo->ts = pQuery->window.skey;
+    pInterpInfo->primaryCol = (colId == PRIMARYKEY_TIMESTAMP_COL_INDEX);
+  
+    if (pQuery->fillVal != NULL) {
+      if (isNull((const char*) &pQuery->fillVal[colIndex], pCtx->inputType)) {
+        pCtx->param[1].nType = TSDB_DATA_TYPE_NULL;
+      } else { // todo refactor, tVariantCreateFromBinary should handle the NULL value
+        tVariantCreateFromBinary(&pCtx->param[1], (char*) &pQuery->fillVal[colIndex], pCtx->inputBytes, pCtx->inputType);
+      }
+    }
   }
 
 #if defined(_DEBUG_VIEW)
@@ -1635,10 +1638,11 @@ static bool isFixedOutputQuery(SQuery *pQuery) {
   return false;
 }
 
+// todo refactor with isLastRowQuery
 static bool isPointInterpoQuery(SQuery *pQuery) {
   for (int32_t i = 0; i < pQuery->numOfOutput; ++i) {
     int32_t functionID = pQuery->pSelectExpr[i].base.functionId;
-    if (functionID == TSDB_FUNC_INTERP || functionID == TSDB_FUNC_LAST_ROW) {
+    if (functionID == TSDB_FUNC_INTERP/* || functionID == TSDB_FUNC_LAST_ROW*/) {
       return true;
     }
   }
@@ -1817,7 +1821,7 @@ static void setScanLimitationByResultBuffer(SQuery *pQuery) {
 /*
  * todo add more parameters to check soon..
  */
-bool vnodeParametersSafetyCheck(SQuery *pQuery) {
+bool colIdCheck(SQuery *pQuery) {
   // load data column information is incorrect
   for (int32_t i = 0; i < pQuery->numOfCols - 1; ++i) {
     if (pQuery->colList[i].colId == pQuery->colList[i + 1].colId) {
@@ -1825,6 +1829,7 @@ bool vnodeParametersSafetyCheck(SQuery *pQuery) {
       return false;
     }
   }
+  
   return true;
 }
 
@@ -1851,7 +1856,7 @@ static bool onlyFirstQuery(SQuery *pQuery) { return onlyOneQueryType(pQuery, TSD
 
 static bool onlyLastQuery(SQuery *pQuery) { return onlyOneQueryType(pQuery, TSDB_FUNC_LAST, TSDB_FUNC_LAST_DST); }
 
-static void changeExecuteScanOrder(SQuery *pQuery, bool metricQuery) {
+static void changeExecuteScanOrder(SQuery *pQuery, bool stableQuery) {
   // in case of point-interpolation query, use asc order scan
   char msg[] = "QInfo:%p scan order changed for %s query, old:%d, new:%d, qrange exchanged, old qrange:%" PRId64
                "-%" PRId64 ", new qrange:%" PRId64 "-%" PRId64;
@@ -1906,7 +1911,7 @@ static void changeExecuteScanOrder(SQuery *pQuery, bool metricQuery) {
     }
 
   } else {  // interval query
-    if (metricQuery) {
+    if (stableQuery) {
       if (onlyFirstQuery(pQuery)) {
         if (!QUERY_IS_ASC_QUERY(pQuery)) {
           qTrace(msg, GET_QINFO_ADDR(pQuery), "only-first stable", pQuery->order.order, TSDB_ORDER_ASC,
@@ -3841,7 +3846,8 @@ bool queryHasRemainResults(SQueryRuntimeEnv* pRuntimeEnv) {
   SQuery *pQuery = pRuntimeEnv->pQuery;
   SFillInfo *pFillInfo = pRuntimeEnv->pFillInfo;
   
-  if (pQuery->fillType == TSDB_FILL_NONE) {
+  // todo refactor
+  if (pQuery->fillType == TSDB_FILL_NONE || (pQuery->fillType != TSDB_FILL_NONE && isPointInterpoQuery(pQuery))) {
     assert(pFillInfo == NULL);
     return false;
   }
@@ -4195,7 +4201,6 @@ static bool skipTimeInterval(SQueryRuntimeEnv *pRuntimeEnv, TSKEY* start) {
   return true;
 }
 
-
 static void setupQueryHandle(void* tsdb, SQInfo* pQInfo, bool isSTableQuery) {
   SQueryRuntimeEnv *pRuntimeEnv = &pQInfo->runtimeEnv;
   SQuery *pQuery = pQInfo->runtimeEnv.pQuery;
@@ -4229,6 +4234,8 @@ static void setupQueryHandle(void* tsdb, SQInfo* pQInfo, bool isSTableQuery) {
 
   if (isFirstLastRowQuery(pQuery)) {
     pRuntimeEnv->pQueryHandle = tsdbQueryLastRow(tsdb, &cond, &pQInfo->tableIdGroupInfo);
+  } else if (isPointInterpoQuery(pQuery)) {
+    pRuntimeEnv->pQueryHandle = tsdbQueryRowsInExternalWindow(tsdb, &cond, &pQInfo->tableIdGroupInfo);
   } else {
     pRuntimeEnv->pQueryHandle = tsdbQueryTables(tsdb, &cond, &pQInfo->tableIdGroupInfo);
   }
@@ -4346,7 +4353,7 @@ int32_t doInitQInfo(SQInfo *pQInfo, void *param, void *tsdb, int32_t vgId, bool
 //  pointInterpSupporterSetData(pQInfo, &interpInfo);
 //  pointInterpSupporterDestroy(&interpInfo);
 
-  if (pQuery->fillType != TSDB_FILL_NONE) {
+  if (pQuery->fillType != TSDB_FILL_NONE && !isPointInterpoQuery(pQuery)) {
     SFillColInfo* pColInfo = taosCreateFillColInfo(pQuery);
     pRuntimeEnv->pFillInfo = taosInitFillInfo(pQuery->order.order, 0, 0, pQuery->rec.capacity, pQuery->numOfOutput,
                                               pQuery->slidingTime, pQuery->fillType, pColInfo);
@@ -5809,7 +5816,7 @@ static SQInfo *createQInfoImpl(SQueryTableMsg *pQueryMsg, SArray* pTableIdList,
     goto _cleanup;
   }
 
-  vnodeParametersSafetyCheck(pQuery);
+  colIdCheck(pQuery);
 
   qTrace("qmsg:%p QInfo:%p created", pQueryMsg, pQInfo);
   return pQInfo;
diff --git a/src/query/src/tvariant.c b/src/query/src/tvariant.c
index c89e9dc5f25084c590452bdbfe1157c5cede2a4f..f21f5d76d9dd6e81c7dde078521b62de5247f769 100644
--- a/src/query/src/tvariant.c
+++ b/src/query/src/tvariant.c
@@ -766,7 +766,7 @@ int32_t tVariantDump(tVariant *pVariant, char *payload, char type) {
     
     case TSDB_DATA_TYPE_BINARY: {
       if (pVariant->nType == TSDB_DATA_TYPE_NULL) {
-        *payload = TSDB_DATA_BINARY_NULL;
+        setVardataNull(payload,TSDB_DATA_TYPE_BINARY);
       } else {
         if (pVariant->nType != TSDB_DATA_TYPE_BINARY) {
           toBinary(pVariant, &payload, &pVariant->nLen);
@@ -786,7 +786,7 @@ int32_t tVariantDump(tVariant *pVariant, char *payload, char type) {
     }
     case TSDB_DATA_TYPE_NCHAR: {
       if (pVariant->nType == TSDB_DATA_TYPE_NULL) {
-        *(uint32_t *) payload = TSDB_DATA_NCHAR_NULL;
+        setVardataNull(payload,TSDB_DATA_TYPE_NCHAR);
       } else {
         if (pVariant->nType != TSDB_DATA_TYPE_NCHAR) {
           toNchar(pVariant, &payload, &pVariant->nLen);
diff --git a/src/tsdb/src/tsdbMeta.c b/src/tsdb/src/tsdbMeta.c
index 95680f95c4565a500a00b14e8dfec9de91d902fe..c09009b4683ae44a0d36ef34b00d8ce1559f51a3 100644
--- a/src/tsdb/src/tsdbMeta.c
+++ b/src/tsdb/src/tsdbMeta.c
@@ -101,6 +101,7 @@ STable *tsdbDecodeTable(void *cont, int contLen) {
     pTable->schema = tdDecodeSchema(&ptr);
   }
 
+  pTable->lastKey = TSKEY_INITIAL_VAL;
   return pTable;
 }
 
@@ -349,7 +350,7 @@ int tsdbCreateTable(TsdbRepoT *repo, STableCfg *pCfg) {
   table->name = calloc(1, size + VARSTR_HEADER_SIZE + 1);
   STR_WITH_SIZE_TO_VARSTR(table->name, pCfg->name, size);
   
-  table->lastKey = 0;
+  table->lastKey = TSKEY_INITIAL_VAL;
   if (IS_CREATE_STABLE(pCfg)) { // TSDB_CHILD_TABLE
     table->type = TSDB_CHILD_TABLE;
     table->superUid = pCfg->superUid;
diff --git a/src/tsdb/src/tsdbRead.c b/src/tsdb/src/tsdbRead.c
index 595217debb75b32ff150bec6a4231da3a0f0f683..32af840a28a2c956e2fe538cc93b0fa332cb9ddc 100644
--- a/src/tsdb/src/tsdbRead.c
+++ b/src/tsdb/src/tsdbRead.c
@@ -117,6 +117,7 @@ typedef struct STsdbQueryHandle {
 } STsdbQueryHandle;
 
 static void changeQueryHandleForLastrowQuery(TsdbQueryHandleT pqHandle);
+static void changeQueryHandleForInterpQuery(TsdbQueryHandleT pHandle);
 
 static void tsdbInitDataBlockLoadInfo(SDataBlockLoadInfo* pBlockLoadInfo) {
   pBlockLoadInfo->slot = -1;
@@ -188,9 +189,6 @@ TsdbQueryHandleT* tsdbQueryTables(TsdbRepoT* tsdb, STsdbQueryCond* pCond, STable
     }
   }
   
-  for(int32_t i = 0; i < numOfCols; ++i) {
-  }
-  
   uTrace("%p total numOfTable:%d in query", pQueryHandle, taosArrayGetSize(pQueryHandle->pTableCheckInfo));
 
   tsdbInitDataBlockLoadInfo(&pQueryHandle->dataBlockLoadInfo);
@@ -213,9 +211,9 @@ TsdbQueryHandleT tsdbQueryRowsInExternalWindow(TsdbRepoT *tsdb, STsdbQueryCond*
   STsdbQueryHandle *pQueryHandle = (STsdbQueryHandle*) tsdbQueryTables(tsdb, pCond, groupList);
   
   pQueryHandle->type = TSDB_QUERY_TYPE_EXTERNAL;
-  pQueryHandle->order = TSDB_ORDER_ASC;
+//  pQueryHandle->outputCapacity = 2;  // only allowed two rows to be loaded
   
-//  changeQueryHandleForLastrowQuery(pQueryHandle);
+  changeQueryHandleForInterpQuery(pQueryHandle);
   return pQueryHandle;
 }
 
@@ -581,18 +579,33 @@ static void handleDataMergeIfNeeded(STsdbQueryHandle* pQueryHandle, SCompBlock*
     }
   
     SArray* sa = getDefaultLoadColumns(pQueryHandle, true);
+  
     doLoadFileDataBlock(pQueryHandle, pBlock, pCheckInfo);
     doMergeTwoLevelData(pQueryHandle, pCheckInfo, pBlock, sa);
     taosArrayDestroy(sa);
     
   } else {
-    pQueryHandle->realNumOfRows = binfo.rows;
-    
-    cur->rows = binfo.rows;
-    cur->win  = binfo.window;
-    cur->mixBlock = false;
-    cur->blockCompleted = true;
-    cur->lastKey = binfo.window.ekey + (ASCENDING_TRAVERSE(pQueryHandle->order)? 1:-1);
+    /*
+     * no data in cache, only load data from file
+     * during the query processing, data in cache will not be checked anymore.
+     *
+     * Here the buffer is not enough, so only part of file block can be loaded into memory buffer
+     */
+//    if (pQueryHandle->outputCapacity < binfo.rows) {
+//      SArray* sa = getDefaultLoadColumns(pQueryHandle, true);
+//      doLoadFileDataBlock(pQueryHandle, pBlock, pCheckInfo);
+//
+//      doMergeTwoLevelData(pQueryHandle, pCheckInfo, pBlock, sa);
+//      taosArrayDestroy(sa);
+//    } else {
+      pQueryHandle->realNumOfRows = binfo.rows;
+  
+      cur->rows = binfo.rows;
+      cur->win  = binfo.window;
+      cur->mixBlock = false;
+      cur->blockCompleted = true;
+      cur->lastKey = binfo.window.ekey + (ASCENDING_TRAVERSE(pQueryHandle->order)? 1:-1);
+//    }
   }
 }
 
@@ -622,15 +635,14 @@ static bool loadFileDataBlock(STsdbQueryHandle* pQueryHandle, SCompBlock* pBlock
       handleDataMergeIfNeeded(pQueryHandle, pBlock, pCheckInfo);
     }
   } else {  //desc order, query ended in current block
-    if (pQueryHandle->window.ekey > pBlock->keyFirst) {
+    if (pQueryHandle->window.ekey > pBlock->keyFirst || pCheckInfo->lastKey < pBlock->keyLast) {
       if (!doLoadFileDataBlock(pQueryHandle, pBlock, pCheckInfo)) {
         return false;
       }
-      
-      SDataCols* pDataCols = pCheckInfo->pDataCols;
+  
+      SDataCols* pTSCol = pQueryHandle->rhelper.pDataCols[0];
       if (pCheckInfo->lastKey < pBlock->keyLast) {
-        cur->pos =
-            binarySearchForKey(pDataCols->cols[0].pData, pBlock->numOfRows, pCheckInfo->lastKey, pQueryHandle->order);
+        cur->pos = binarySearchForKey(pTSCol->cols[0].pData, pBlock->numOfRows, pCheckInfo->lastKey, pQueryHandle->order);
       } else {
         cur->pos = pBlock->numOfRows - 1;
       }
@@ -1011,7 +1023,7 @@ int32_t binarySearchForKey(char* pValue, int num, TSKEY key, int order) {
   firstPos = 0;
   lastPos = num - 1;
 
-  if (order == 0) {
+  if (order == TSDB_ORDER_DESC) {
     // find the first position which is smaller than the key
     while (1) {
       if (key >= keyList[lastPos]) return lastPos;
@@ -1307,12 +1319,116 @@ static bool doHasDataInBuffer(STsdbQueryHandle* pQueryHandle) {
 }
 
 // handle data in cache situation
-bool tsdbNextDataBlock(TsdbQueryHandleT* pqHandle) {
-  STsdbQueryHandle* pQueryHandle = (STsdbQueryHandle*) pqHandle;
+bool tsdbNextDataBlock(TsdbQueryHandleT* pHandle) {
+  STsdbQueryHandle* pQueryHandle = (STsdbQueryHandle*) pHandle;
   
   size_t numOfTables = taosArrayGetSize(pQueryHandle->pTableCheckInfo);
   assert(numOfTables > 0);
   
+  if (pQueryHandle->type == TSDB_QUERY_TYPE_EXTERNAL) {
+    pQueryHandle->type = TSDB_QUERY_TYPE_ALL;
+    pQueryHandle->order = TSDB_ORDER_DESC;
+    
+    if (!tsdbNextDataBlock(pHandle)) {
+      return false;
+    }
+    
+    SArray* sa = getDefaultLoadColumns(pQueryHandle, true);
+    /*SDataBlockInfo* pBlockInfo =*/ tsdbRetrieveDataBlockInfo(pHandle);
+    /*SArray *pDataBlock = */tsdbRetrieveDataBlock(pHandle, sa);
+  
+    if (pQueryHandle->cur.win.ekey == pQueryHandle->window.skey) {
+      // data already retrieve, discard other data rows and return
+      int32_t numOfCols = QH_GET_NUM_OF_COLS(pQueryHandle);
+      for (int32_t i = 0; i < numOfCols; ++i) {
+        SColumnInfoData* pCol = taosArrayGet(pQueryHandle->pColumns, i);
+        memcpy(pCol->pData, pCol->pData + pCol->info.bytes * (pQueryHandle->cur.rows-1), pCol->info.bytes);
+      }
+  
+      pQueryHandle->cur.win  = (STimeWindow){pQueryHandle->window.skey, pQueryHandle->window.skey};
+      pQueryHandle->window   = pQueryHandle->cur.win;
+      pQueryHandle->cur.rows = 1;
+      pQueryHandle->type = TSDB_QUERY_TYPE_EXTERNAL;
+      return true;
+    } else {
+      STsdbQueryHandle* pSecQueryHandle = calloc(1, sizeof(STsdbQueryHandle));
+      pSecQueryHandle->order       = TSDB_ORDER_ASC;
+      pSecQueryHandle->window      = (STimeWindow) {pQueryHandle->window.skey, INT64_MAX};
+      pSecQueryHandle->pTsdb       = pQueryHandle->pTsdb;
+      pSecQueryHandle->type        = TSDB_QUERY_TYPE_ALL;
+      pSecQueryHandle->cur.fid     = -1;
+      pSecQueryHandle->cur.win     = TSWINDOW_INITIALIZER;
+      pSecQueryHandle->checkFiles  = true;
+      pSecQueryHandle->activeIndex = 0;
+      pSecQueryHandle->outputCapacity = ((STsdbRepo*)pSecQueryHandle->pTsdb)->config.maxRowsPerFileBlock;
+  
+      tsdbInitReadHelper(&pSecQueryHandle->rhelper, (STsdbRepo*) pSecQueryHandle->pTsdb);
+  
+      // allocate buffer in order to load data blocks from file
+      int32_t numOfCols = QH_GET_NUM_OF_COLS(pQueryHandle);
+  
+      pSecQueryHandle->statis = calloc(numOfCols, sizeof(SDataStatis));
+      pSecQueryHandle->pColumns = taosArrayInit(numOfCols, sizeof(SColumnInfoData));
+  
+      for (int32_t i = 0; i < numOfCols; ++i) {
+        SColumnInfoData colInfo = {{0}, 0};
+        SColumnInfoData* pCol = taosArrayGet(pQueryHandle->pColumns, i);
+        
+        colInfo.info = pCol->info;
+        colInfo.pData = calloc(1, EXTRA_BYTES + pQueryHandle->outputCapacity * pCol->info.bytes);
+        taosArrayPush(pSecQueryHandle->pColumns, &colInfo);
+        pSecQueryHandle->statis[i].colId = colInfo.info.colId;
+      }
+  
+      size_t si = taosArrayGetSize(pQueryHandle->pTableCheckInfo);
+      pSecQueryHandle->pTableCheckInfo = taosArrayInit(si, sizeof(STableCheckInfo));
+      STsdbMeta* pMeta = tsdbGetMeta(pQueryHandle->pTsdb);
+      assert(pMeta != NULL);
+  
+      for (int32_t j = 0; j < si; ++j) {
+        STableCheckInfo* pCheckInfo = (STableCheckInfo*) taosArrayGet(pQueryHandle->pTableCheckInfo, j);
+    
+        STableCheckInfo info = {
+            .lastKey = pSecQueryHandle->window.skey,
+            .tableId = pCheckInfo->tableId,
+            .pTableObj = pCheckInfo->pTableObj,
+        };
+        
+        taosArrayPush(pSecQueryHandle->pTableCheckInfo, &info);
+      }
+  
+      tsdbInitDataBlockLoadInfo(&pSecQueryHandle->dataBlockLoadInfo);
+      tsdbInitCompBlockLoadInfo(&pSecQueryHandle->compBlockLoadInfo);
+  
+      bool ret = tsdbNextDataBlock((void*) pSecQueryHandle);
+      assert(ret);
+
+      /*SDataBlockInfo* pBlockInfo =*/ tsdbRetrieveDataBlockInfo((void*) pSecQueryHandle);
+      /*SArray *pDataBlock = */tsdbRetrieveDataBlock((void*) pSecQueryHandle, sa);
+  
+      for (int32_t i = 0; i < numOfCols; ++i) {
+        SColumnInfoData* pCol = taosArrayGet(pQueryHandle->pColumns, i);
+        memcpy(pCol->pData, pCol->pData + pCol->info.bytes * (pQueryHandle->cur.rows-1), pCol->info.bytes);
+  
+        SColumnInfoData* pCol1 = taosArrayGet(pSecQueryHandle->pColumns, i);
+        assert(pCol->info.colId == pCol1->info.colId);
+        
+        memcpy(pCol->pData + pCol->info.bytes, pCol1->pData, pCol1->info.bytes);
+      }
+  
+      SColumnInfoData* pTSCol = taosArrayGet(pQueryHandle->pColumns, 0);
+      
+      pQueryHandle->cur.win  = (STimeWindow){((TSKEY*)pTSCol->pData)[0], ((TSKEY*)pTSCol->pData)[1]};
+      pQueryHandle->window   = pQueryHandle->cur.win;
+      pQueryHandle->cur.rows = 2;
+      
+      tsdbCleanupQueryHandle(pSecQueryHandle);
+    }
+    
+    pQueryHandle->type = TSDB_QUERY_TYPE_EXTERNAL;
+    return true;
+  }
+  
   if (pQueryHandle->checkFiles) {
     if (getDataBlocksInFiles(pQueryHandle)) {
       return true;
@@ -1322,7 +1438,6 @@ bool tsdbNextDataBlock(TsdbQueryHandleT* pqHandle) {
     pQueryHandle->checkFiles  = false;
   }
   
-  // TODO: opt by using lastKeyOnFile
   // TODO: opt by consider the scan order
   return doHasDataInBuffer(pQueryHandle);
 }
@@ -1336,23 +1451,22 @@ void changeQueryHandleForLastrowQuery(TsdbQueryHandleT pqHandle) {
   // todo consider the query time window, current last_row does not apply the query time window
   size_t numOfTables = taosArrayGetSize(pQueryHandle->pTableCheckInfo);
   
-  TSKEY key = 0;
+  TSKEY key = TSKEY_INITIAL_VAL;
   int32_t index = -1;
   
   for(int32_t i = 0; i < numOfTables; ++i) {
     STableCheckInfo* pCheckInfo = taosArrayGet(pQueryHandle->pTableCheckInfo, i);
-    if (pCheckInfo->pTableObj->lastKey > key) {  //todo lastKey should not be 0 by default
+    if (pCheckInfo->pTableObj->lastKey > key) {
       key = pCheckInfo->pTableObj->lastKey;
       index = i;
     }
   }
   
-  // todo, there are no data in all the tables. opt performance
   if (index == -1) {
     return;
   }
   
-  // erase all other elements in array list, todo refactor
+  // erase all other elements in array list
   size_t size = taosArrayGetSize(pQueryHandle->pTableCheckInfo);
   for (int32_t i = 0; i < size; ++i) {
     if (i == index) {
@@ -1371,9 +1485,7 @@ void changeQueryHandleForLastrowQuery(TsdbQueryHandleT pqHandle) {
   }
   
   STableCheckInfo info = *(STableCheckInfo*) taosArrayGet(pQueryHandle->pTableCheckInfo, index);
-  taosArrayDestroy(pQueryHandle->pTableCheckInfo);
-  
-  pQueryHandle->pTableCheckInfo = taosArrayInit(1, sizeof(STableCheckInfo));
+  taosArrayClear(pQueryHandle->pTableCheckInfo);
   
   info.lastKey = key;
   taosArrayPush(pQueryHandle->pTableCheckInfo, &info);
@@ -1382,6 +1494,43 @@ void changeQueryHandleForLastrowQuery(TsdbQueryHandleT pqHandle) {
   pQueryHandle->window = (STimeWindow) {key, key};
 }
 
+static void changeQueryHandleForInterpQuery(TsdbQueryHandleT pHandle) {
+  // filter the queried time stamp in the first place
+  STsdbQueryHandle* pQueryHandle = (STsdbQueryHandle*) pHandle;
+  pQueryHandle->order = TSDB_ORDER_DESC;
+  
+  assert(pQueryHandle->window.skey == pQueryHandle->window.ekey);
+  
+  // starts from the buffer in case of descending timestamp order check data blocks
+  // todo consider the query time window, current last_row does not apply the query time window
+  size_t numOfTables = taosArrayGetSize(pQueryHandle->pTableCheckInfo);
+  
+  int32_t i = 0;
+  while(i < numOfTables) {
+    STableCheckInfo* pCheckInfo = taosArrayGet(pQueryHandle->pTableCheckInfo, i);
+    if (pQueryHandle->window.skey <= pCheckInfo->pTableObj->lastKey &&
+        pCheckInfo->pTableObj->lastKey != TSKEY_INITIAL_VAL) {
+      break;
+    }
+    
+    i++;
+  }
+  
+  // there are no data in all the tables
+  if (i == numOfTables) {
+    return;
+  }
+  
+  STableCheckInfo info = *(STableCheckInfo*) taosArrayGet(pQueryHandle->pTableCheckInfo, i);
+  taosArrayClear(pQueryHandle->pTableCheckInfo);
+  
+  info.lastKey = pQueryHandle->window.skey;
+  taosArrayPush(pQueryHandle->pTableCheckInfo, &info);
+  
+  // update the query time window according to the chosen last timestamp
+  pQueryHandle->window = (STimeWindow) {info.lastKey, TSKEY_INITIAL_VAL};
+}
+
 static int tsdbReadRowsFromCache(SSkipListIterator* pIter, STable* pTable, TSKEY maxKey, int maxRowsToRead, TSKEY* skey, TSKEY* ekey,
                                  STsdbQueryHandle* pQueryHandle) {
   int     numOfRows = 0;
@@ -1469,14 +1618,15 @@ static int tsdbReadRowsFromCache(SSkipListIterator* pIter, STable* pTable, TSKEY
 // copy data from cache into data block
 SDataBlockInfo tsdbRetrieveDataBlockInfo(TsdbQueryHandleT* pQueryHandle) {
   STsdbQueryHandle* pHandle = (STsdbQueryHandle*)pQueryHandle;
-
+  STableCheckInfo* pCheckInfo = taosArrayGet(pHandle->pTableCheckInfo, pHandle->activeIndex);
+  SQueryFilePos* cur = &pHandle->cur;
+  
+  STable* pTable = pCheckInfo->pTableObj;
   int32_t step = ASCENDING_TRAVERSE(pHandle->order)? 1:-1;
   
   // there are data in file
   if (pHandle->cur.fid >= 0) {
-    STableBlockInfo* pBlockInfo = &pHandle->pDataBlockInfo[pHandle->cur.slot];
-    STable* pTable = pBlockInfo->pTableCheckInfo->pTableObj;
-
+    
     SDataBlockInfo blockInfo = {
         .uid = pTable->tableId.uid,
         .tid = pTable->tableId.tid,
@@ -1487,15 +1637,12 @@ SDataBlockInfo tsdbRetrieveDataBlockInfo(TsdbQueryHandleT* pQueryHandle) {
 
     return blockInfo;
   } else {
-    STableCheckInfo* pCheckInfo = taosArrayGet(pHandle->pTableCheckInfo, pHandle->activeIndex);
-    SQueryFilePos* cur = &pHandle->cur;
-    
-    STable* pTable = pCheckInfo->pTableObj;
-    if (pTable->mem != NULL) { // create mem table iterator if it is not created yet
+    // TODO  move to next function
+    if (pTable->mem != NULL && pHandle->type != TSDB_QUERY_TYPE_EXTERNAL) { // create mem table iterator if it is not created yet
       assert(pCheckInfo->iter != NULL);
       STimeWindow* win = &cur->win;
       
-      pHandle->cur.rows = tsdbReadRowsFromCache(pCheckInfo->iter, pCheckInfo->pTableObj, pHandle->window.ekey,
+      cur->rows = tsdbReadRowsFromCache(pCheckInfo->iter, pCheckInfo->pTableObj, pHandle->window.ekey,
           pHandle->outputCapacity, &win->skey, &win->ekey, pHandle);  // todo refactor API
 
       // update the last key value
@@ -1505,7 +1652,7 @@ SDataBlockInfo tsdbRetrieveDataBlockInfo(TsdbQueryHandleT* pQueryHandle) {
     }
   
     if (!ASCENDING_TRAVERSE(pHandle->order)) {
-      SWAP(pHandle->cur.win.skey, pHandle->cur.win.ekey, TSKEY);
+      SWAP(cur->win.skey, cur->win.ekey, TSKEY);
     }
     
     SDataBlockInfo blockInfo = {
diff --git a/tests/script/general/parser/interp_test.sim b/tests/script/general/parser/interp_test.sim
index 3e6d5de85bd315886493985fc3d2ac7e324efbee..8bffae4af634e9c04c4d5f4614d51e1e1b33ffba 100644
--- a/tests/script/general/parser/interp_test.sim
+++ b/tests/script/general/parser/interp_test.sim
@@ -117,6 +117,7 @@ $tb = $tbPrefix . 0
     return -1
   endi
   if $data01 != NULL then
+    print expect NULL, actual $data01
     return -1
   endi
   if $data02 != NULL then
@@ -213,6 +214,7 @@ $tb = $tbPrefix . 0
     return -1
   endi
   if $data03 != 0.00000 then
+    print expect 0.00000, actual:$data03
     return -1
   endi
 #  if $data04 != NULL then
diff --git a/tests/script/general/parser/testSuite.sim b/tests/script/general/parser/testSuite.sim
index ac867c9f7ff483a8fb646a777ca34ceb74ecca4b..a61cf84217ec58105322e489504091bfb7daad0c 100644
--- a/tests/script/general/parser/testSuite.sim
+++ b/tests/script/general/parser/testSuite.sim
@@ -62,16 +62,19 @@ sleep 2000
 run general/parser/tbnameIn.sim
 sleep 2000
 run general/parser/projection_limit_offset.sim
-
 sleep 2000
 run general/parser/limit2.sim
-sleep 2000
-run general/parser/slimit.sim
-
 sleep 2000
 run general/parser/fill.sim
 sleep 2000
 run general/parser/fill_stb.sim
+sleep 2000
+run general/parser/where.sim
+sleep 2000
+run general/parser/slimit.sim
+sleep 2000
+run general/parser/select_with_tags.sim
+
 sleep 2000
 run general/parser/tags_dynamically_specifiy.sim
 sleep 2000
@@ -86,8 +89,6 @@ run general/parser/stream_on_sys.sim
 sleep 2000
 run general/parser/stream.sim
 
-sleep 2000
-run general/parser/where.sim
 sleep 2000
 #run general/parser/repeatAlter.sim
 sleep 2000
@@ -97,11 +98,8 @@ run general/parser/join.sim
 sleep 2000
 run general/parser/join_multivnode.sim
 
-sleep 2000
-run general/parser/select_with_tags.sim
 sleep 2000
 run general/parser/groupby.sim
-
 sleep 2000
 run general/parser/binary_escapeCharacter.sim
 sleep 2000