diff --git a/src/client/src/tscAsync.c b/src/client/src/tscAsync.c
index 366faa15dca19392386683dcb499b8dc5b97334a..985a6741f95ded4e3f430e5ee656434d2f4cef42 100644
--- a/src/client/src/tscAsync.c
+++ b/src/client/src/tscAsync.c
@@ -514,7 +514,7 @@ void tscTableMetaCallBack(void *param, TAOS_RES *res, int code) {
     tscTansformSQLFunctionForSTableQuery(pQueryInfo);
     tscIncStreamExecutionCount(pSql->pStream);
   } else {
-    tscTrace("%p get tableMeta/metricMeta successfully", pSql);
+    tscTrace("%p get tableMeta successfully", pSql);
   }
 
   tscDoQuery(pSql);
diff --git a/src/client/src/tscSecondaryMerge.c b/src/client/src/tscSecondaryMerge.c
index d69f6d295f13bb9515b3c5800f4c4b4bb0764daa..1d4ed51f32a68cb39d511f83c5ea1f47a3aeb4eb 100644
--- a/src/client/src/tscSecondaryMerge.c
+++ b/src/client/src/tscSecondaryMerge.c
@@ -605,7 +605,7 @@ int32_t tscLocalReducerEnvCreate(SSqlObj *pSql, tExtMemBuffer ***pMemBuffer, tOr
   SQueryInfo *    pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);
   STableMetaInfo *pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
 
-//  (*pMemBuffer) = (tExtMemBuffer **)malloc(POINTER_BYTES * pTableMetaInfo->pMetricMeta->numOfVnodes);
+  (*pMemBuffer) = (tExtMemBuffer **)malloc(POINTER_BYTES * 1);
   if (*pMemBuffer == NULL) {
     tscError("%p failed to allocate memory", pSql);
     pRes->code = TSDB_CODE_CLI_OUT_OF_MEMORY;
@@ -636,10 +636,11 @@ int32_t tscLocalReducerEnvCreate(SSqlObj *pSql, tExtMemBuffer ***pMemBuffer, tOr
 
   pModel = createColumnModel(pSchema, pQueryInfo->exprsInfo.numOfExprs, capacity);
 
-//  for (int32_t i = 0; i < pTableMetaInfo->pMetricMeta->numOfVnodes; ++i) {
-//    (*pMemBuffer)[i] = createExtMemBuffer(nBufferSizes, rlen, pModel);
-//    (*pMemBuffer)[i]->flushModel = MULTIPLE_APPEND_MODEL;
-//  }
+  size_t numOfSubs = taosArrayGetSize(pTableMetaInfo->vgroupIdList);
+  for (int32_t i = 0; i < numOfSubs; ++i) {
+    (*pMemBuffer)[i] = createExtMemBuffer(nBufferSizes, rlen, pModel);
+    (*pMemBuffer)[i]->flushModel = MULTIPLE_APPEND_MODEL;
+  }
 
   if (createOrderDescriptor(pOrderDesc, pCmd, pModel) != TSDB_CODE_SUCCESS) {
     pRes->code = TSDB_CODE_CLI_OUT_OF_MEMORY;
diff --git a/src/client/src/tscServer.c b/src/client/src/tscServer.c
index 498a33838966bd4de795f0ab9474cd71bc83988c..111ebc4e8c690cef9c52ea214dacde0cf5d58dfd 100644
--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@@ -509,31 +509,31 @@ int tscBuildRetrieveMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
 }
 
 int tscBuildSubmitMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
-  SSubmitMsg *pShellMsg;
-  char *           pMsg, *pStart;
-
   SQueryInfo *pQueryInfo = tscGetQueryInfoDetail(&pSql->cmd, 0);
   STableMeta* pTableMeta = tscGetMetaInfo(pQueryInfo, 0)->pTableMeta;
   
-  pStart = pSql->cmd.payload + tsRpcHeadSize;
-  pMsg = pStart;
+  char* pMsg = pSql->cmd.payload + tsRpcHeadSize;
+  
+  // NOTE: shell message size should not include SMsgDesc
+  int32_t size = pSql->cmd.payloadLen - sizeof(SMsgDesc);
   
   SMsgDesc* pMsgDesc = (SMsgDesc*) pMsg;
-  pMsgDesc->numOfVnodes = htonl(1);       //set the number of vnodes
+  
+  pMsgDesc->numOfVnodes = htonl(1);       //todo set the right number of vnodes
   pMsg += sizeof(SMsgDesc);
   
-  pShellMsg = (SSubmitMsg *)pMsg;
+  SSubmitMsg *pShellMsg = (SSubmitMsg *)pMsg;
+  
   pShellMsg->header.vgId = htonl(pTableMeta->vgId);
-  pShellMsg->header.contLen = htonl(pSql->cmd.payloadLen);
+  pShellMsg->header.contLen = htonl(size);
   pShellMsg->length = pShellMsg->header.contLen;
   
   pShellMsg->numOfBlocks = htonl(pSql->cmd.numOfTablesInSubmit);  // number of meters to be inserted
 
-  // pSql->cmd.payloadLen is set during parse sql routine, so we do not use it here
+  // pSql->cmd.payloadLen is set during copying data into paylaod
   pSql->cmd.msgType = TSDB_MSG_TYPE_SUBMIT;
+  tscTrace("%p build submit msg, vgId:%d numOfVnodes:%d", pSql, pTableMeta->vgId, htons(pMsgDesc->numOfVnodes));
   
-//  tscTrace("%p update submit msg vnode:%s:%d", pSql, taosIpStr(pTableMeta->vpeerDesc[pTableMeta->index].ip),
-//           htons(pShellMsg->vnode));
   return TSDB_CODE_SUCCESS;
 }
 
diff --git a/src/client/src/tscSubquery.c b/src/client/src/tscSubquery.c
index 21ce270466f19396f095124eb1818d4b48a866ba..b0c7b68ab4cfc263f6728d4ff8e95c224ec988cf 100644
--- a/src/client/src/tscSubquery.c
+++ b/src/client/src/tscSubquery.c
@@ -1006,13 +1006,12 @@ int32_t tscHandleMasterSTableQuery(SSqlObj *pSql) {
   
   pRes->qhandle = 1;  // hack the qhandle check
   
-  const uint32_t nBufferSize = (1 << 16);  // 64KB
+  const uint32_t nBufferSize = (1u << 16);  // 64KB
   
   SQueryInfo *    pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);
   STableMetaInfo *pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
   
-  int32_t numOfSubQueries = 0;
-//  int32_t numOfSubQueries = pTableMetaInfo->pMetricMeta->numOfVnodes;
+  int32_t numOfSubQueries = taosArrayGetSize(pTableMetaInfo->vgroupIdList);
   assert(numOfSubQueries > 0);
   
   int32_t ret = tscLocalReducerEnvCreate(pSql, &pMemoryBuf, &pDesc, &pModel, nBufferSize);
@@ -1118,7 +1117,7 @@ static void tscFreeSubSqlObj(SRetrieveSupport *trsupport, SSqlObj *pSql) {
   tfree(trsupport);
 }
 
-static void tscRetrieveFromVnodeCallBack(void *param, TAOS_RES *tres, int numOfRows);
+static void tscRetrieveFromDnodeCallBack(void *param, TAOS_RES *tres, int numOfRows);
 
 static void tscAbortFurtherRetryRetrieval(SRetrieveSupport *trsupport, TAOS_RES *tres, int32_t errCode) {
 // set no disk space error info
@@ -1140,7 +1139,7 @@ static void tscAbortFurtherRetryRetrieval(SRetrieveSupport *trsupport, TAOS_RES
   
   pthread_mutex_unlock(&trsupport->queryMutex);
   
-  tscRetrieveFromVnodeCallBack(trsupport, tres, trsupport->pState->code);
+  tscRetrieveFromDnodeCallBack(trsupport, tres, trsupport->pState->code);
 }
 
 static void tscHandleSubRetrievalError(SRetrieveSupport *trsupport, SSqlObj *pSql, int numOfRows) {
@@ -1235,7 +1234,86 @@ static void tscHandleSubRetrievalError(SRetrieveSupport *trsupport, SSqlObj *pSq
   }
 }
 
-static void tscRetrieveFromVnodeCallBack(void *param, TAOS_RES *tres, int numOfRows) {
+static void tscAllDataRetrievedFromDnode(SRetrieveSupport *trsupport, SSqlObj* pSql) {
+  int32_t           idx = trsupport->subqueryIndex;
+  SSqlObj *         pPObj = trsupport->pParentSqlObj;
+  tOrderDescriptor *pDesc = trsupport->pOrderDescriptor;
+  
+  SSubqueryState* pState = trsupport->pState;
+  SQueryInfo *pQueryInfo = tscGetQueryInfoDetail(&pSql->cmd, 0);
+  
+  // data in from current vnode is stored in cache and disk
+  uint32_t numOfRowsFromSubquery = trsupport->pExtMemBuffer[idx]->numOfTotalElems + trsupport->localBuffer->numOfElems;
+//    tscTrace("%p sub:%p all data retrieved from ip:%u,vid:%d, numOfRows:%d, orderOfSub:%d", pPObj, pSql, pSvd->ip,
+//             pSvd->vnode, numOfRowsFromSubquery, idx);
+  
+  tColModelCompact(pDesc->pColumnModel, trsupport->localBuffer, pDesc->pColumnModel->capacity);
+
+#ifdef _DEBUG_VIEW
+  printf("%" PRIu64 " rows data flushed to disk:\n", trsupport->localBuffer->numOfElems);
+    SSrcColumnInfo colInfo[256] = {0};
+    tscGetSrcColumnInfo(colInfo, pQueryInfo);
+    tColModelDisplayEx(pDesc->pColumnModel, trsupport->localBuffer->data, trsupport->localBuffer->numOfElems,
+                       trsupport->localBuffer->numOfElems, colInfo);
+#endif
+  
+  if (tsTotalTmpDirGB != 0 && tsAvailTmpDirGB < tsMinimalTmpDirGB) {
+    tscError("%p sub:%p client disk space remain %.3f GB, need at least %.3f GB, stop query", pPObj, pSql,
+             tsAvailTmpDirGB, tsMinimalTmpDirGB);
+    tscAbortFurtherRetryRetrieval(trsupport, pSql, TSDB_CODE_CLI_NO_DISKSPACE);
+    return;
+  }
+  
+  // each result for a vnode is ordered as an independant list,
+  // then used as an input of loser tree for disk-based merge routine
+  int32_t ret = tscFlushTmpBuffer(trsupport->pExtMemBuffer[idx], pDesc, trsupport->localBuffer,
+                                  pQueryInfo->groupbyExpr.orderType);
+  if (ret != 0) { // set no disk space error info, and abort retry
+    return tscAbortFurtherRetryRetrieval(trsupport, pSql, TSDB_CODE_CLI_NO_DISKSPACE);
+  }
+  
+  // keep this value local variable, since the pState variable may be released by other threads, if atomic_add opertion
+  // increases the finished value up to pState->numOfTotal value, which means all subqueries are completed.
+  // In this case, the comparsion between finished value and released pState->numOfTotal is not safe.
+  int32_t numOfTotal = pState->numOfTotal;
+  
+  int32_t finished = atomic_add_fetch_32(&pState->numOfCompleted, 1);
+  if (finished < numOfTotal) {
+    tscTrace("%p sub:%p orderOfSub:%d freed, finished subqueries:%d", pPObj, pSql, trsupport->subqueryIndex, finished);
+    return tscFreeSubSqlObj(trsupport, pSql);
+  }
+  
+  // all sub-queries are returned, start to local merge process
+  pDesc->pColumnModel->capacity = trsupport->pExtMemBuffer[idx]->numOfElemsPerPage;
+  
+  tscTrace("%p retrieve from %d vnodes completed.final NumOfRows:%d,start to build loser tree", pPObj,
+           pState->numOfTotal, pState->numOfRetrievedRows);
+  
+  SQueryInfo *pPQueryInfo = tscGetQueryInfoDetail(&pPObj->cmd, 0);
+  tscClearInterpInfo(pPQueryInfo);
+  
+  tscCreateLocalReducer(trsupport->pExtMemBuffer, pState->numOfTotal, pDesc, trsupport->pFinalColModel,
+                        &pPObj->cmd, &pPObj->res);
+  tscTrace("%p build loser tree completed", pPObj);
+  
+  pPObj->res.precision = pSql->res.precision;
+  pPObj->res.numOfRows = 0;
+  pPObj->res.row = 0;
+  
+  // only free once
+  tfree(trsupport->pState);
+  tscFreeSubSqlObj(trsupport, pSql);
+  
+  // set the command flag must be after the semaphore been correctly set.
+  pPObj->cmd.command = TSDB_SQL_RETRIEVE_METRIC;
+  if (pPObj->res.code == TSDB_CODE_SUCCESS) {
+    (*pPObj->fp)(pPObj->param, pPObj, 0);
+  } else {
+    tscQueueAsyncRes(pPObj);
+  }
+}
+
+static void tscRetrieveFromDnodeCallBack(void *param, TAOS_RES *tres, int numOfRows) {
   SRetrieveSupport *trsupport = (SRetrieveSupport *)param;
   int32_t           idx = trsupport->subqueryIndex;
   SSqlObj *         pPObj = trsupport->pParentSqlObj;
@@ -1264,15 +1342,15 @@ static void tscRetrieveFromVnodeCallBack(void *param, TAOS_RES *tres, int numOfR
   STableMetaInfo *pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
   
 //  SVnodeSidList *vnodeInfo = tscGetVnodeSidList(pTableMetaInfo->pMetricMeta, idx);
-  SVnodeSidList *vnodeInfo = 0;
-  SVnodeDesc *   pSvd = &vnodeInfo->vpeerDesc[vnodeInfo->index];
+//  SVnodeSidList *vnodeInfo = 0;
+//  SVnodeDesc *   pSvd = &vnodeInfo->vpeerDesc[vnodeInfo->index];
   
   if (numOfRows > 0) {
     assert(pRes->numOfRows == numOfRows);
     int64_t num = atomic_add_fetch_64(&pState->numOfRetrievedRows, numOfRows);
     
-    tscTrace("%p sub:%p retrieve numOfRows:%d totalNumOfRows:%d from ip:%u,vid:%d,orderOfSub:%d", pPObj, pSql,
-             pRes->numOfRows, pState->numOfRetrievedRows, pSvd->ip, pSvd->vnode, idx);
+//    tscTrace("%p sub:%p retrieve numOfRows:%d totalNumOfRows:%d from ip:%u,vid:%d,orderOfSub:%d", pPObj, pSql,
+//             pRes->numOfRows, pState->numOfRetrievedRows, pSvd->ip, pSvd->vnode, idx);
     
     if (num > tsMaxNumOfOrderedResults && tscIsProjectionQueryOnSTable(pQueryInfo, 0)) {
       tscError("%p sub:%p num of OrderedRes is too many, max allowed:%" PRId64 " , current:%" PRId64,
@@ -1298,85 +1376,16 @@ static void tscRetrieveFromVnodeCallBack(void *param, TAOS_RES *tres, int numOfR
     
     int32_t ret = saveToBuffer(trsupport->pExtMemBuffer[idx], pDesc, trsupport->localBuffer, pRes->data,
                                pRes->numOfRows, pQueryInfo->groupbyExpr.orderType);
-    if (ret < 0) {
-      // set no disk space error info, and abort retry
+    if (ret < 0) { // set no disk space error info, and abort retry
       tscAbortFurtherRetryRetrieval(trsupport, tres, TSDB_CODE_CLI_NO_DISKSPACE);
-    } else {
+    } else if (pRes->completed) {
+      tscAllDataRetrievedFromDnode(trsupport, pSql);
+    } else { // continue fetch data from dnode
       pthread_mutex_unlock(&trsupport->queryMutex);
-      taos_fetch_rows_a(tres, tscRetrieveFromVnodeCallBack, param);
-    }
-    
-  } else {  // all data has been retrieved to client
-    /* data in from current vnode is stored in cache and disk */
-    uint32_t numOfRowsFromVnode = trsupport->pExtMemBuffer[idx]->numOfTotalElems + trsupport->localBuffer->numOfElems;
-    tscTrace("%p sub:%p all data retrieved from ip:%u,vid:%d, numOfRows:%d, orderOfSub:%d", pPObj, pSql, pSvd->ip,
-             pSvd->vnode, numOfRowsFromVnode, idx);
-    
-    tColModelCompact(pDesc->pColumnModel, trsupport->localBuffer, pDesc->pColumnModel->capacity);
-
-#ifdef _DEBUG_VIEW
-    printf("%" PRIu64 " rows data flushed to disk:\n", trsupport->localBuffer->numOfElems);
-    SSrcColumnInfo colInfo[256] = {0};
-    tscGetSrcColumnInfo(colInfo, pQueryInfo);
-    tColModelDisplayEx(pDesc->pColumnModel, trsupport->localBuffer->data, trsupport->localBuffer->numOfElems,
-                       trsupport->localBuffer->numOfElems, colInfo);
-#endif
-    
-    if (tsTotalTmpDirGB != 0 && tsAvailTmpDirGB < tsMinimalTmpDirGB) {
-      tscError("%p sub:%p client disk space remain %.3f GB, need at least %.3f GB, stop query", pPObj, pSql,
-               tsAvailTmpDirGB, tsMinimalTmpDirGB);
-      tscAbortFurtherRetryRetrieval(trsupport, tres, TSDB_CODE_CLI_NO_DISKSPACE);
-      return;
-    }
-    
-    // each result for a vnode is ordered as an independant list,
-    // then used as an input of loser tree for disk-based merge routine
-    int32_t ret = tscFlushTmpBuffer(trsupport->pExtMemBuffer[idx], pDesc, trsupport->localBuffer,
-                                    pQueryInfo->groupbyExpr.orderType);
-    if (ret != 0) {
-      /* set no disk space error info, and abort retry */
-      return tscAbortFurtherRetryRetrieval(trsupport, tres, TSDB_CODE_CLI_NO_DISKSPACE);
-    }
-    
-    // keep this value local variable, since the pState variable may be released by other threads, if atomic_add opertion
-    // increases the finished value up to pState->numOfTotal value, which means all subqueries are completed.
-    // In this case, the comparsion between finished value and released pState->numOfTotal is not safe.
-    int32_t numOfTotal = pState->numOfTotal;
-    
-    int32_t finished = atomic_add_fetch_32(&pState->numOfCompleted, 1);
-    if (finished < numOfTotal) {
-      tscTrace("%p sub:%p orderOfSub:%d freed, finished subqueries:%d", pPObj, pSql, trsupport->subqueryIndex, finished);
-      return tscFreeSubSqlObj(trsupport, pSql);
-    }
-    
-    // all sub-queries are returned, start to local merge process
-    pDesc->pColumnModel->capacity = trsupport->pExtMemBuffer[idx]->numOfElemsPerPage;
-    
-    tscTrace("%p retrieve from %d vnodes completed.final NumOfRows:%d,start to build loser tree", pPObj,
-             pState->numOfTotal, pState->numOfRetrievedRows);
-    
-    SQueryInfo *pPQueryInfo = tscGetQueryInfoDetail(&pPObj->cmd, 0);
-    tscClearInterpInfo(pPQueryInfo);
-    
-    tscCreateLocalReducer(trsupport->pExtMemBuffer, pState->numOfTotal, pDesc, trsupport->pFinalColModel,
-                          &pPObj->cmd, &pPObj->res);
-    tscTrace("%p build loser tree completed", pPObj);
-    
-    pPObj->res.precision = pSql->res.precision;
-    pPObj->res.numOfRows = 0;
-    pPObj->res.row = 0;
-    
-    // only free once
-    tfree(trsupport->pState);
-    tscFreeSubSqlObj(trsupport, pSql);
-    
-    // set the command flag must be after the semaphore been correctly set.
-    pPObj->cmd.command = TSDB_SQL_RETRIEVE_METRIC;
-    if (pPObj->res.code == TSDB_CODE_SUCCESS) {
-      (*pPObj->fp)(pPObj->param, pPObj, 0);
-    } else {
-      tscQueueAsyncRes(pPObj);
+      taos_fetch_rows_a(tres, tscRetrieveFromDnodeCallBack, param);
     }
+  } else { // all data has been retrieved to client
+    tscAllDataRetrievedFromDnode(trsupport, pSql);
   }
 }
 
@@ -1436,7 +1445,7 @@ void tscRetrieveDataRes(void *param, TAOS_RES *tres, int code) {
   
   /*
    * if a query on a vnode is failed, all retrieve operations from vnode that occurs later
-   * than this one are actually not necessary, we simply call the tscRetrieveFromVnodeCallBack
+   * than this one are actually not necessary, we simply call the tscRetrieveFromDnodeCallBack
    * function to abort current and remain retrieve process.
    *
    * NOTE: threadsafe is required.
@@ -1474,7 +1483,7 @@ void tscRetrieveDataRes(void *param, TAOS_RES *tres, int code) {
                trsupport->subqueryIndex, pState->code);
     }
     
-    tscRetrieveFromVnodeCallBack(param, tres, pState->code);
+    tscRetrieveFromDnodeCallBack(param, tres, pState->code);
   } else {  // success, proceed to retrieve data from dnode
     if (vnodeInfo != NULL) {
       tscTrace("%p sub:%p query complete,ip:%u,vid:%d,orderOfSub:%d,retrieve data", trsupport->pParentSqlObj, pSql,
@@ -1485,7 +1494,7 @@ void tscRetrieveDataRes(void *param, TAOS_RES *tres, int code) {
                trsupport->subqueryIndex);
     }
     
-    taos_fetch_rows_a(tres, tscRetrieveFromVnodeCallBack, param);
+    taos_fetch_rows_a(tres, tscRetrieveFromDnodeCallBack, param);
   }
 }
 
diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index 18f491aa9edaaa60efbc6cbca6bfc54e532f8b9c..ec6881db3f5ae4f1e32dbf790bfb662ae3df84c5 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -608,7 +608,7 @@ int32_t tscCopyDataBlockToPayload(SSqlObj* pSql, STableDataBlocks* pDataBlock) {
    * the payloadLen should be actual message body size
    * the old value of payloadLen is the allocated payload size
    */
-  pCmd->payloadLen = pDataBlock->nAllocSize - tsRpcHeadSize - sizeof(SMsgDesc);
+  pCmd->payloadLen = pDataBlock->nAllocSize - tsRpcHeadSize;
 
   assert(pCmd->allocSize >= pCmd->payloadLen + tsRpcHeadSize + 100 && pCmd->payloadLen > 0);
   return TSDB_CODE_SUCCESS;
diff --git a/src/client/tests/timeParseTest.cpp b/src/client/tests/timeParseTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..1f53d50c1f3b4f57571508060db4f19616eb49de
--- /dev/null
+++ b/src/client/tests/timeParseTest.cpp
@@ -0,0 +1,167 @@
+#include <gtest/gtest.h>
+#include <cassert>
+#include <iostream>
+
+#include "taos.h"
+#include "tstoken.h"
+#include "ttime.h"
+#include "tutil.h"
+
+int main(int argc, char** argv) {
+  testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
+
+extern void deltaToUtcInitOnce();
+/* test parse time function */
+TEST(testCase, parse_time) {
+  
+  taos_options(TSDB_OPTION_TIMEZONE, "GMT-8");
+  deltaToUtcInitOnce();
+  
+  char t1[] = "2018-1-1 1:1:1.952798";
+  char t13[] = "1970-1-1 0:0:0";
+
+  int64_t time = 0, time1 = 0;
+
+  taosParseTime(t1, &time, strlen(t1), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, 1514739661952);
+
+  taosParseTime(t13, &time, strlen(t13), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, timezone * MILLISECOND_PER_SECOND);
+
+  char t2[] = "2018-1-1T1:1:1.952Z";
+  taosParseTime(t2, &time, strlen(t2), TSDB_TIME_PRECISION_MILLI);
+
+  EXPECT_EQ(time, 1514739661952 + 28800000);
+
+  char t3[] = "2018-1-1 1:01:01.952";
+  taosParseTime(t3, &time, strlen(t3), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, 1514739661952);
+
+  char t4[] = "2018-1-1 1:01:01.9";
+  char t5[] = "2018-1-1 1:01:1.900";
+  char t6[] = "2018-01-01 1:1:1.90";
+  char t7[] = "2018-01-01 01:01:01.9";
+  char t8[] = "2018-01-01 01:01:01.9007865";
+
+  taosParseTime(t4, &time, strlen(t4), TSDB_TIME_PRECISION_MILLI);
+  taosParseTime(t5, &time1, strlen(t5), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, time1);
+
+  taosParseTime(t4, &time, strlen(t4), TSDB_TIME_PRECISION_MILLI);
+  taosParseTime(t6, &time1, strlen(t6), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, time1);
+
+  taosParseTime(t4, &time, strlen(t4), TSDB_TIME_PRECISION_MILLI);
+  taosParseTime(t7, &time1, strlen(t7), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, time1);
+
+  taosParseTime(t5, &time, strlen(t5), TSDB_TIME_PRECISION_MILLI);
+  taosParseTime(t8, &time1, strlen(t8), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, time1);
+
+  char t9[] = "2017-4-3 1:1:2.980";
+  char t10[] = "2017-4-3T2:1:2.98+9:00";
+  taosParseTime(t9, &time, strlen(t9), TSDB_TIME_PRECISION_MILLI);
+  taosParseTime(t10, &time1, strlen(t10), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, time1);
+
+  char t11[] = "2017-4-3T2:1:2.98+09:00";
+  taosParseTime(t11, &time, strlen(t11), TSDB_TIME_PRECISION_MILLI);
+  taosParseTime(t10, &time1, strlen(t10), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, time1);
+
+  char t12[] = "2017-4-3T2:1:2.98+0900";
+  taosParseTime(t11, &time, strlen(t11), TSDB_TIME_PRECISION_MILLI);
+  taosParseTime(t12, &time1, strlen(t12), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, time1);
+
+  taos_options(TSDB_OPTION_TIMEZONE, "UTC");  
+  deltaToUtcInitOnce();
+  
+  taosParseTime(t13, &time, strlen(t13), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, 0);
+
+  taos_options(TSDB_OPTION_TIMEZONE, "Asia/Shanghai");
+  deltaToUtcInitOnce();
+  
+  char t14[] = "1970-1-1T0:0:0Z";
+  taosParseTime(t14, &time, strlen(t14), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, 0);
+
+  char t40[] = "1970-1-1 0:0:0.999999999";
+  taosParseTime(t40, &time, strlen(t40), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, 999 + timezone * MILLISECOND_PER_SECOND);
+
+  char t41[] = "1997-1-1 0:0:0.999999999";
+  taosParseTime(t41, &time, strlen(t41), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, 852048000999);
+
+  int64_t k = timezone;
+  char    t42[] = "1997-1-1T0:0:0.999999999Z";
+  taosParseTime(t42, &time, strlen(t42), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, 852048000999 - timezone * MILLISECOND_PER_SECOND);
+
+  ////////////////////////////////////////////////////////////////////
+  // illegal timestamp format
+  char t15[] = "2017-12-33 0:0:0";
+  EXPECT_EQ(taosParseTime(t15, &time, strlen(t15), TSDB_TIME_PRECISION_MILLI), -1);
+
+  char t16[] = "2017-12-31 99:0:0";
+  EXPECT_EQ(taosParseTime(t16, &time, strlen(t16), TSDB_TIME_PRECISION_MILLI), -1);
+
+  char t17[] = "2017-12-31T9:0:0";
+  EXPECT_EQ(taosParseTime(t17, &time, strlen(t17), TSDB_TIME_PRECISION_MILLI), -1);
+
+  char t18[] = "2017-12-31T9:0:0.Z";
+  EXPECT_EQ(taosParseTime(t18, &time, strlen(t18), TSDB_TIME_PRECISION_MILLI), -1);
+
+  char t19[] = "2017-12-31 9:0:0.-1";
+  EXPECT_EQ(taosParseTime(t19, &time, strlen(t19), TSDB_TIME_PRECISION_MILLI), -1);
+
+  char t20[] = "2017-12-31 9:0:0.1+12:99";
+  EXPECT_EQ(taosParseTime(t20, &time, strlen(t20), TSDB_TIME_PRECISION_MILLI), 0);
+  EXPECT_EQ(time, 1514682000100);
+
+  char t21[] = "2017-12-31T9:0:0.1+12:99";
+  EXPECT_EQ(taosParseTime(t21, &time, strlen(t21), TSDB_TIME_PRECISION_MILLI), -1);
+
+  char t22[] = "2017-12-31 9:0:0.1+13:1";
+  EXPECT_EQ(taosParseTime(t22, &time, strlen(t22), TSDB_TIME_PRECISION_MILLI), 0);
+
+  char t23[] = "2017-12-31T9:0:0.1+13:1";
+  EXPECT_EQ(taosParseTime(t23, &time, strlen(t23), TSDB_TIME_PRECISION_MILLI), 0);
+
+
+  //======================== add some case ============================//
+  
+  char b1[] = "9999-12-31 23:59:59.999";
+  taosParseTime(b1, &time, strlen(b1), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, 253402271999999);
+
+
+  char b2[] = "2020-01-01 01:01:01.321";
+  taosParseTime(b2, &time, strlen(b2), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, 1577811661321);
+
+  taos_options(TSDB_OPTION_TIMEZONE, "America/New_York");  
+  deltaToUtcInitOnce();
+  
+  taosParseTime(t13, &time, strlen(t13), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, 18000 * MILLISECOND_PER_SECOND);
+
+  taos_options(TSDB_OPTION_TIMEZONE, "Asia/Tokyo");  
+  deltaToUtcInitOnce();
+  
+  taosParseTime(t13, &time, strlen(t13), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, -32400 * MILLISECOND_PER_SECOND);
+
+  taos_options(TSDB_OPTION_TIMEZONE, "Asia/Shanghai");
+  deltaToUtcInitOnce();
+  
+  taosParseTime(t13, &time, strlen(t13), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, -28800 * MILLISECOND_PER_SECOND);
+}
+
+
diff --git a/src/inc/taosmsg.h b/src/inc/taosmsg.h
index 9ac06e4199becba6759f6279d8622ba88475b9b8..4632c67c3cd5dc65267a151f63dcad40cea24b1f 100644
--- a/src/inc/taosmsg.h
+++ b/src/inc/taosmsg.h
@@ -188,15 +188,6 @@ extern char *taosMsg[];
 
 #pragma pack(push, 1)
 
-// typedef struct {
-//  int32_t  vnode;
-//  int32_t  sid;
-//  int32_t  sversion;
-//  uint64_t uid;
-//  int16_t  numOfRows;
-//  char     payLoad[];
-//} SShellSubmitBlock;
-
 typedef struct {
   int32_t numOfVnodes;
 } SMsgDesc;
diff --git a/src/query/CMakeLists.txt b/src/query/CMakeLists.txt
index 0e51962f49999ae55c1c18aa5acd9d9baba64be7..a6462f98558d163b05d3b8b1cbc2cad23ae7cae4 100644
--- a/src/query/CMakeLists.txt
+++ b/src/query/CMakeLists.txt
@@ -12,4 +12,6 @@ IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
   AUX_SOURCE_DIRECTORY(src SRC)
   ADD_LIBRARY(query ${SRC})
   TARGET_LINK_LIBRARIES(query tsdb tutil m rt)
-ENDIF ()
\ No newline at end of file
+ENDIF ()
+
+ADD_SUBDIRECTORY(tests)
\ No newline at end of file
diff --git a/src/query/inc/qtsbuf.h b/src/query/inc/qtsbuf.h
index 1afdb0cd6cb9175b14675d06446afbe3a891df27..8e014e5feb781b2c87209118d1c4c8a7c2d13813 100644
--- a/src/query/inc/qtsbuf.h
+++ b/src/query/inc/qtsbuf.h
@@ -48,10 +48,10 @@ typedef struct STSElem {
 } STSElem;
 
 typedef struct STSCursor {
-  int32_t vnodeIndex;
-  int32_t blockIndex;
-  int32_t tsIndex;
-  int32_t order;
+  int32_t  vnodeIndex;
+  int32_t  blockIndex;
+  int32_t  tsIndex;
+  uint32_t order;
 } STSCursor;
 
 typedef struct STSBlock {
diff --git a/src/query/inc/queryExecutor.h b/src/query/inc/queryExecutor.h
index 2e1d86a94261cfe692411fcd5ce0b566423aa991..5adce04efa44d7e85bc9ccf482dd21e0deff20b5 100644
--- a/src/query/inc/queryExecutor.h
+++ b/src/query/inc/queryExecutor.h
@@ -32,12 +32,6 @@ typedef struct SData {
   char    data[];
 } SData;
 
-enum {
-//  ST_QUERY_KILLED = 0,     // query killed
-  ST_QUERY_PAUSED = 1,     // query paused, due to full of the response buffer
-  ST_QUERY_COMPLETED = 2,  // query completed
-};
-
 struct SColumnFilterElem;
 typedef bool (*__filter_func_t)(struct SColumnFilterElem* pFilter, char* val1, char* val2);
 typedef int32_t (*__block_search_fn_t)(char* data, int32_t num, int64_t key, int32_t order);
@@ -60,18 +54,20 @@ typedef struct SWindowStatus {
 } SWindowStatus;
 
 typedef struct SWindowResult {
-  uint16_t      numOfRows;
+  uint16_t      numOfRows;   // number of rows of current  time window
   SPosInfo      pos;         // Position of current result in disk-based output buffer
   SResultInfo*  resultInfo;  // For each result column, there is a resultInfo
   STimeWindow   window;      // The time window that current result covers.
-  SWindowStatus status;
+  SWindowStatus status;      // this result status: closed or opened
 } SWindowResult;
 
 typedef struct SResultRec {
-  int64_t total;
-  int64_t size;
-  int64_t capacity;
-  int32_t threshold;   // the threshold size, when the number of rows in result buffer, return to client
+  int64_t total;     // total generated result size in rows
+  int64_t size;      // current result set size in rows
+  int64_t capacity;  // capacity of current result output buffer
+  
+  // result size threshold in rows. If the result buffer is larger than this, pause query and return to client
+  int32_t threshold;
 } SResultRec;
 
 typedef struct SWindowResInfo {
@@ -99,7 +95,6 @@ typedef struct SSingleColumnFilterInfo {
   void*              pData;
 } SSingleColumnFilterInfo;
 
-/* intermediate pos during multimeter query involves interval */
 typedef struct STableQueryInfo {
   int64_t     lastKey;
   STimeWindow win;
@@ -107,7 +102,7 @@ typedef struct STableQueryInfo {
   int16_t     queryRangeSet;  // denote if the query range is set, only available for interval query
   int64_t     tag;
   STSCursor   cur;
-  int32_t     sid;  // for retrieve the page id list
+  int32_t     tid;  // for retrieve the page id list
 
   SWindowResInfo windowResInfo;
 } STableQueryInfo;
@@ -116,7 +111,6 @@ typedef struct STableDataInfo {
   int32_t          numOfBlocks;
   int32_t          start;     // start block index
   int32_t          tableIndex;
-  void*            pMeterObj;
   int32_t          groupIdx;  // group id in table list
   STableQueryInfo* pTableQInfo;
 } STableDataInfo;
diff --git a/src/query/src/queryExecutor.c b/src/query/src/queryExecutor.c
index 2f219368080b135cb380293f565dfb332320b538..83cbae42664407d1245adfc9740fa31be5af1de0 100644
--- a/src/query/src/queryExecutor.c
+++ b/src/query/src/queryExecutor.c
@@ -375,29 +375,6 @@ bool doRevisedResultsByLimit(SQInfo *pQInfo) {
   return false;
 }
 
-/**
- *
- * @param pQuery
- * @param pDataBlockInfo
- * @param forwardStep
- * @return  TRUE means query not completed, FALSE means query is completed
- */
-static bool queryPaused(SQuery *pQuery, SDataBlockInfo *pDataBlockInfo, int32_t forwardStep) {
-  // output buffer is full, pause current query
-  if (Q_STATUS_EQUAL(pQuery->status, QUERY_RESBUF_FULL)) {
-    //    assert((QUERY_IS_ASC_QUERY(pQuery) && forwardStep + pQuery->pos <= pDataBlockInfo->size) ||
-    //        (!QUERY_IS_ASC_QUERY(pQuery) && pQuery->pos - forwardStep + 1 >= 0));
-    //
-    return true;
-  }
-
-  if (Q_STATUS_EQUAL(pQuery->status, QUERY_COMPLETED)) {
-    return true;
-  }
-
-  return false;
-}
-
 static bool isTopBottomQuery(SQuery *pQuery) {
   for (int32_t i = 0; i < pQuery->numOfOutputCols; ++i) {
     int32_t functionId = pQuery->pSelectExpr[i].pBase.functionId;
@@ -1690,7 +1667,7 @@ bool notHasQueryTimeRange(SQuery *pQuery) {
          (pQuery->window.skey == INT64_MAX && pQuery->window.ekey == 0 && (!QUERY_IS_ASC_QUERY(pQuery)));
 }
 
-bool needSupplementaryScan(SQuery *pQuery) {
+static bool needReverseScan(SQuery *pQuery) {
   for (int32_t i = 0; i < pQuery->numOfOutputCols; ++i) {
     int32_t functionId = pQuery->pSelectExpr[i].pBase.functionId;
     if (functionId == TSDB_FUNC_TS || functionId == TSDB_FUNC_TS_DUMMY || functionId == TSDB_FUNC_TAG) {
@@ -2227,7 +2204,7 @@ static int32_t getInitialPageNum(SQInfo *pQInfo) {
     size_t s = taosArrayGetSize(pQInfo->pTableIdList);
     num = MAX(s, INITIAL_RESULT_ROWS_VALUE);
   } else {  // for super table query, one page for each subset
-            //    num = pQInfo->pSidSet->numOfSubSet;
+    num = 1;//pQInfo->pSidSet->numOfSubSet;
   }
 
   assert(num > 0);
@@ -2664,7 +2641,6 @@ static int64_t doScanAllDataBlocks(SQueryRuntimeEnv *pRuntimeEnv) {
 
     int32_t numOfRes = 0;
     SDataStatis *pStatis = NULL;
-    
     SArray *pDataBlock = loadDataBlockOnDemand(pRuntimeEnv, &blockInfo, &pStatis);
     int32_t forwardStep = tableApplyFunctionsOnBlock(pRuntimeEnv, &blockInfo, pStatis, binarySearchForKey, &numOfRes,
                                                      &pRuntimeEnv->windowResInfo, pDataBlock);
@@ -2950,7 +2926,7 @@ int32_t tableResultComparFn(const void *pLeft, const void *pRight, void *param)
   return leftTimestamp > rightTimestamp ? 1 : -1;
 }
 
-int32_t mergeMetersResultToOneGroups(SQInfo *pQInfo) {
+int32_t mergeResultsToGroup(SQInfo *pQInfo) {
   SQueryRuntimeEnv *pRuntimeEnv = &pQInfo->runtimeEnv;
   SQuery *          pQuery = pRuntimeEnv->pQuery;
 
@@ -2990,7 +2966,7 @@ void copyResToQueryResultBuf(SQInfo *pQInfo, SQuery *pQuery) {
     pQInfo->numOfGroupResultPages = 0;
 
     // current results of group has been sent to client, try next group
-    if (mergeMetersResultToOneGroups(pQInfo) != TSDB_CODE_SUCCESS) {
+    if (mergeResultsToGroup(pQInfo) != TSDB_CODE_SUCCESS) {
       return;  // failed to save data in the disk
     }
 
@@ -3071,9 +3047,9 @@ int32_t doMergeMetersResultsToGroupRes(SQInfo *pQInfo, STableDataInfo *pTableDat
   // todo opt for the case of one table per group
   int32_t numOfMeters = 0;
   for (int32_t i = start; i < end; ++i) {
-    int32_t sid = pTableDataInfo[i].pTableQInfo->sid;
+    int32_t tid = pTableDataInfo[i].pTableQInfo->tid;
 
-    SIDList list = getDataBufPagesIdList(pRuntimeEnv->pResultBuf, sid);
+    SIDList list = getDataBufPagesIdList(pRuntimeEnv->pResultBuf, tid);
     if (list.size > 0 && pTableDataInfo[i].pTableQInfo->windowResInfo.size > 0) {
       pTableList[numOfMeters] = &pTableDataInfo[i];
       numOfMeters += 1;
@@ -3240,10 +3216,9 @@ void resetMergeResultBuf(SQuery *pQuery, SQLFunctionCtx *pCtx, SResultInfo *pRes
   }
 }
 
-void setMeterDataInfo(STableDataInfo *pTableDataInfo, void *pMeterObj, int32_t meterIdx, int32_t groupId) {
-  pTableDataInfo->pMeterObj = pMeterObj;
+void setTableDataInfo(STableDataInfo *pTableDataInfo, int32_t tableIndex, int32_t groupId) {
   pTableDataInfo->groupIdx = groupId;
-  pTableDataInfo->tableIndex = meterIdx;
+  pTableDataInfo->tableIndex = tableIndex;
 }
 
 static void doDisableFunctsForSupplementaryScan(SQuery *pQuery, SWindowResInfo *pWindowResInfo, int32_t order) {
@@ -3297,7 +3272,7 @@ void disableFunctForTableSuppleScan(SQueryRuntimeEnv *pRuntimeEnv, int32_t order
   pQuery->order.order = pQuery->order.order ^ 1u;
 }
 
-void disableFunctForSuppleScan(SQInfo *pQInfo, int32_t order) {
+void disableFuncForReverseScan(SQInfo *pQInfo, int32_t order) {
   SQueryRuntimeEnv *pRuntimeEnv = &pQInfo->runtimeEnv;
   SQuery *          pQuery = pRuntimeEnv->pQuery;
 
@@ -3322,7 +3297,7 @@ void disableFunctForSuppleScan(SQInfo *pQInfo, int32_t order) {
   pQuery->order.order = (pQuery->order.order) ^ 1u;
 }
 
-void enableFunctForMasterScan(SQueryRuntimeEnv *pRuntimeEnv, int32_t order) {
+void enableFuncForForwardScan(SQueryRuntimeEnv *pRuntimeEnv, int32_t order) {
   SQuery *pQuery = pRuntimeEnv->pQuery;
 
   for (int32_t i = 0; i < pQuery->numOfOutputCols; ++i) {
@@ -3483,7 +3458,7 @@ static void doSingleMeterSupplementScan(SQueryRuntimeEnv *pRuntimeEnv) {
   SQuery *     pQuery = pRuntimeEnv->pQuery;
   SQueryStatus qStatus = {0};
 
-  if (!needSupplementaryScan(pQuery)) {
+  if (!needReverseScan(pQuery)) {
     return;
   }
 
@@ -3503,7 +3478,7 @@ static void doSingleMeterSupplementScan(SQueryRuntimeEnv *pRuntimeEnv) {
   doScanAllDataBlocks(pRuntimeEnv);
 
   queryStatusRestore(pRuntimeEnv, &qStatus);
-  enableFunctForMasterScan(pRuntimeEnv, pQuery->order.order);
+  enableFuncForForwardScan(pRuntimeEnv, pQuery->order.order);
   SET_MASTER_SCAN_FLAG(pRuntimeEnv);
 }
 
@@ -3562,7 +3537,7 @@ bool needScanDataBlocksAgain(SQueryRuntimeEnv *pRuntimeEnv) {
   return toContinue;
 }
 
-void vnodeScanAllData(SQueryRuntimeEnv *pRuntimeEnv) {
+void scanAllDataBlocks(SQueryRuntimeEnv *pRuntimeEnv) {
   SQuery *pQuery = pRuntimeEnv->pQuery;
   setQueryStatus(pQuery, QUERY_NOT_COMPLETED);
 
@@ -3588,10 +3563,7 @@ void vnodeScanAllData(SQueryRuntimeEnv *pRuntimeEnv) {
       break;
     }
 
-    /*
-     * set the correct start position, and load the corresponding block in buffer for next
-     * round scan all data blocks.
-     */
+    // set the correct start position, and load the corresponding block in buffer for next round scan all data blocks.
     int32_t ret = tsdbDataBlockSeek(pRuntimeEnv->pQueryHandle, pos);
 
     status = pQuery->status;
@@ -3675,18 +3647,13 @@ static bool hasMainOutput(SQuery *pQuery) {
   return false;
 }
 
-STableQueryInfo *createMeterQueryInfo(SQInfo *pQInfo, int32_t sid, TSKEY skey, TSKEY ekey) {
-  SQueryRuntimeEnv *pRuntimeEnv = &pQInfo->runtimeEnv;
-
+STableQueryInfo *createTableQueryInfo(SQueryRuntimeEnv *pRuntimeEnv, int32_t tid, STimeWindow win) {
   STableQueryInfo *pTableQueryInfo = calloc(1, sizeof(STableQueryInfo));
 
-  pTableQueryInfo->win = (STimeWindow){
-      .skey = skey,
-      .ekey = ekey,
-  };
-  pTableQueryInfo->lastKey = skey;
+  pTableQueryInfo->win = win;
+  pTableQueryInfo->lastKey = win.skey;
 
-  pTableQueryInfo->sid = sid;
+  pTableQueryInfo->tid = tid;
   pTableQueryInfo->cur.vnodeIndex = -1;
 
   initWindowResInfo(&pTableQueryInfo->windowResInfo, pRuntimeEnv, 100, 100, TSDB_DATA_TYPE_INT);
@@ -3702,7 +3669,7 @@ void destroyMeterQueryInfo(STableQueryInfo *pTableQueryInfo, int32_t numOfCols)
   free(pTableQueryInfo);
 }
 
-void changeMeterQueryInfoForSuppleQuery(SQuery *pQuery, STableQueryInfo *pTableQueryInfo, TSKEY skey, TSKEY ekey) {
+void changeMeterQueryInfoForSuppleQuery(SQuery *pQuery, STableQueryInfo *pTableQueryInfo) {
   if (pTableQueryInfo == NULL) {
     return;
   }
@@ -3906,7 +3873,7 @@ static int32_t getNumOfSubset(SQInfo *pQInfo) {
   if (isGroupbyNormalCol(pQuery->pGroupbyExpr) || (isIntervalQuery(pQuery))) {
     totalSubset = numOfClosedTimeWindow(&pQInfo->runtimeEnv.windowResInfo);
   } else {
-    //    totalSubset = pQInfo->pSidSet->numOfSubSet;
+    totalSubset = 1;//pQInfo->pSidSet->numOfSubSet;
   }
 
   return totalSubset;
@@ -3942,19 +3909,18 @@ static int32_t doCopyToSData(SQInfo *pQInfo, SWindowResult *result, int32_t orde
 
     int32_t numOfRowsToCopy = result[i].numOfRows - pQInfo->offset;
     int32_t oldOffset = pQInfo->offset;
-    assert(0);
 
     /*
      * current output space is not enough to keep all the result data of this group, only copy partial results
      * to SQuery object's result buffer
      */
-    //    if (numOfRowsToCopy > pQuery->pointsToRead - numOfResult) {
-    //      numOfRowsToCopy = pQuery->pointsToRead - numOfResult;
-    //      pQInfo->offset += numOfRowsToCopy;
-    //    } else {
-    //      pQInfo->offset = 0;
-    //      pQInfo->subgroupIdx += 1;
-    //    }
+    if (numOfRowsToCopy > pQuery->rec.capacity - numOfResult) {
+      numOfRowsToCopy = pQuery->rec.capacity - numOfResult;
+      pQInfo->offset += numOfRowsToCopy;
+    } else {
+      pQInfo->offset = 0;
+      pQInfo->subgroupIdx += 1;
+    }
 
     for (int32_t j = 0; j < pQuery->numOfOutputCols; ++j) {
       int32_t size = pRuntimeEnv->pCtx[j].outputBytes;
@@ -3965,13 +3931,12 @@ static int32_t doCopyToSData(SQInfo *pQInfo, SWindowResult *result, int32_t orde
     }
 
     numOfResult += numOfRowsToCopy;
-    assert(0);
-    //    if (numOfResult == pQuery->rec.pointsToRead) {
-    //      break;
-    //    }
+    if (numOfResult == pQuery->rec.capacity) {
+      break;
+    }
   }
 
-  dTrace("QInfo:%p copy data to SQuery buf completed", GET_QINFO_ADDR(pQuery));
+  dTrace("QInfo:%p copy data to SQuery buf completed", pQInfo);
 
 #ifdef _DEBUG_VIEW
   displayInterResult(pQuery->sdata, pQuery, numOfResult);
@@ -4014,9 +3979,8 @@ static void updateWindowResNumOfRes(SQueryRuntimeEnv *pRuntimeEnv, STableDataInf
   }
 }
 
-void stableApplyFunctionsOnBlock_(SQInfo *pQInfo, STableDataInfo *pTableDataInfo, SDataBlockInfo *pDataBlockInfo,
+void stableApplyFunctionsOnBlock(SQueryRuntimeEnv* pRuntimeEnv, STableDataInfo *pTableDataInfo, SDataBlockInfo *pDataBlockInfo,
                                   SDataStatis *pStatis, SArray *pDataBlock, __block_search_fn_t searchFn) {
-  SQueryRuntimeEnv *pRuntimeEnv = &pQInfo->runtimeEnv;
   SQuery *          pQuery = pRuntimeEnv->pQuery;
   STableQueryInfo * pTableQueryInfo = pTableDataInfo->pTableQInfo;
   SWindowResInfo *  pWindowResInfo = &pTableQueryInfo->windowResInfo;
@@ -4169,10 +4133,11 @@ int32_t vnodeQueryResultInterpolate(SQInfo *pQInfo, tFilePage **pDst, tFilePage
 }
 
 void vnodePrintQueryStatistics(SQInfo *pQInfo) {
+#if 0
   SQueryRuntimeEnv *pRuntimeEnv = &pQInfo->runtimeEnv;
 
   SQuery *pQuery = pRuntimeEnv->pQuery;
-#if 0
+
   SQueryCostSummary *pSummary = &pRuntimeEnv->summary;
   if (pRuntimeEnv->pResultBuf == NULL) {
     pSummary->tmpBufferInDisk = 0;
@@ -4213,41 +4178,30 @@ void vnodePrintQueryStatistics(SQInfo *pQInfo) {
 #endif
 }
 
-int32_t initQInfo(SQInfo *pQInfo, void *param, void* tsdb) {
+int32_t doInitializeQInfo(SQInfo *pQInfo, void *param, void* tsdb, bool isSTableQuery) {
+  SQueryRuntimeEnv *pRuntimeEnv = &pQInfo->runtimeEnv;
+  
   SQuery *pQuery = pQInfo->runtimeEnv.pQuery;
   int32_t code = TSDB_CODE_SUCCESS;
 
-  // only the successful complete requries the sem_post/over = 1 operations.
-  if ((QUERY_IS_ASC_QUERY(pQuery) && (pQuery->window.skey > pQuery->window.ekey)) ||
-      (!QUERY_IS_ASC_QUERY(pQuery) && (pQuery->window.ekey > pQuery->window.skey))) {
-    dTrace("QInfo:%p no result in time range %" PRId64 "-%" PRId64 ", order %d", pQInfo, pQuery->window.skey,
-           pQuery->window.ekey, pQuery->order.order);
-
-    sem_post(&pQInfo->dataReady);
-    setQueryStatus(pQuery, QUERY_COMPLETED);
-    return TSDB_CODE_SUCCESS;
-  }
-
   setScanLimitationByResultBuffer(pQuery);
   changeExecuteScanOrder(pQuery, false);
 
   // dataInCache requires lastKey value
   pQuery->lastKey = pQuery->window.skey;
 
-  STsdbQueryCond cond = {0};
-
-  cond.twindow = (STimeWindow){.skey = pQuery->window.skey, .ekey = pQuery->window.ekey};
-  cond.order = pQuery->order.order;
-  cond.colList = *pQuery->colList;
+  STsdbQueryCond cond = {
+    .twindow = pQuery->window,
+    .order   = pQuery->order.order,
+    .colList = *pQuery->colList,
+  };
 
   SArray *cols = taosArrayInit(pQuery->numOfCols, sizeof(pQuery->colList[0]));
   for (int32_t i = 0; i < pQuery->numOfCols; ++i) {
     taosArrayPush(cols, &pQuery->colList[i]);
   }
-
-  pQInfo->runtimeEnv.pQueryHandle = tsdbQueryByTableId(tsdb, &cond, pQInfo->pTableIdList, cols);
-
-  SQueryRuntimeEnv *pRuntimeEnv = &pQInfo->runtimeEnv;
+  
+  pRuntimeEnv->pQueryHandle = tsdbQueryByTableId(tsdb, &cond, pQInfo->pTableIdList, cols);
   pRuntimeEnv->pQuery = pQuery;
 
   pRuntimeEnv->pTSBuf = param;
@@ -4258,15 +4212,34 @@ int32_t initQInfo(SQInfo *pQInfo, void *param, void* tsdb) {
   }
 
   // create runtime environment
-  code = setupQueryRuntimeEnv(&pQInfo->runtimeEnv, NULL, pQuery->order.order, false);
+  code = setupQueryRuntimeEnv(pRuntimeEnv, NULL, pQuery->order.order, isSTableQuery);
   if (code != TSDB_CODE_SUCCESS) {
     return code;
   }
 
-  pRuntimeEnv->numOfRowsPerPage = getNumOfRowsInResultPage(pQuery, false);
-  if (isGroupbyNormalCol(pQuery->pGroupbyExpr) || isIntervalQuery(pQuery)) {
+  pRuntimeEnv->numOfRowsPerPage = getNumOfRowsInResultPage(pQuery, isSTableQuery);
+  
+  if (isSTableQuery) {
+    int32_t rows = getInitialPageNum(pQInfo);
+    code = createDiskbasedResultBuffer(&pRuntimeEnv->pResultBuf, rows, pQuery->rowSize);
+    if (code != TSDB_CODE_SUCCESS) {
+      return code;
+    }
+  
+    if (pQuery->intervalTime == 0) {
+      int16_t type = TSDB_DATA_TYPE_NULL;
+    
+      if (isGroupbyNormalCol(pQuery->pGroupbyExpr)) {  // group by columns not tags;
+        type = getGroupbyColumnType(pQuery, pQuery->pGroupbyExpr);
+      } else {
+        type = TSDB_DATA_TYPE_INT;  // group id
+      }
+    
+      initWindowResInfo(&pRuntimeEnv->windowResInfo, pRuntimeEnv, 512, 4096, type);
+    }
+  
+  } else if (isGroupbyNormalCol(pQuery->pGroupbyExpr) || isIntervalQuery(pQuery)) {
     int32_t rows = getInitialPageNum(pQInfo);
-
     code = createDiskbasedResultBuffer(&pRuntimeEnv->pResultBuf, rows, pQuery->rowSize);
     if (code != TSDB_CODE_SUCCESS) {
       return code;
@@ -4363,59 +4336,56 @@ static void enableExecutionForNextTable(SQueryRuntimeEnv *pRuntimeEnv) {
   }
 }
 
-static void queryOnDataBlocks(SQInfo *pQInfo, STableDataInfo *pMeterDataInfo) {
+static int64_t queryOnDataBlocks(SQInfo *pQInfo) {
   SQueryRuntimeEnv *pRuntimeEnv = &pQInfo->runtimeEnv;
   SQuery *          pQuery = pRuntimeEnv->pQuery;
-
-  //  dTrace("QInfo:%p start to check data blocks in %d files", pQInfo, pVnodeFileInfo->numOfFiles);
+  
+  int64_t st = taosGetTimestampMs();
+  size_t numOfTables = taosArrayGetSize(pQInfo->pTableIdList);
+  
   tsdb_query_handle_t *pQueryHandle = pRuntimeEnv->pQueryHandle;
   while (tsdbNextDataBlock(pQueryHandle)) {
     if (isQueryKilled(pQInfo)) {
       break;
     }
 
-    // prepare the STableDataInfo struct for each table
-
     SDataBlockInfo blockInfo = tsdbRetrieveDataBlockInfo(pQueryHandle);
-    //    SMeterObj *    pMeterObj = getMeterObj(pSupporter->pMetersHashTable, blockInfo.sid);
-
-    //    pQInfo->pObj = pMeterObj;
-    //    pRuntimeEnv->pMeterObj = pMeterObj;
-
-    STableDataInfo *pTableDataInfo = NULL;
-    //    for (int32_t i = 0; i < pSupporter->pSidSet->numOfTables; ++i) {
-    //      if (pMeterDataInfo[i].pMeterObj == pMeterObj) {
-    //        pTableDataInfo = &pMeterDataInfo[i];
-    //        break;
-    //      }
-    //    }
+    STableDataInfo* pTableDataInfo = NULL;
+    
+    // todo opt performance
+    for(int32_t i = 0; i < numOfTables; ++i) {
+      if (pQInfo->pTableDataInfo[i].pTableQInfo->tid == blockInfo.sid) {
+        pTableDataInfo = &pQInfo->pTableDataInfo[i];
+        break;
+      }
+    }
 
-    assert(pTableDataInfo != NULL);
+    assert(pTableDataInfo != NULL && pTableDataInfo->pTableQInfo != NULL);
     STableQueryInfo *pTableQueryInfo = pTableDataInfo->pTableQInfo;
 
-    if (pTableDataInfo->pTableQInfo == NULL) {
-      //      pTableDataInfo->pTableQInfo = createMeterQueryInfo(pQInfo, pMeterObj->sid, pQuery->skey, pQuery->ekey);
-    }
-
     restoreIntervalQueryRange(pRuntimeEnv, pTableQueryInfo);
 
     SDataStatis *pStatis = NULL;
     SArray *     pDataBlock = loadDataBlockOnDemand(pRuntimeEnv, &blockInfo, &pStatis);
 
     TSKEY nextKey = blockInfo.window.ekey;
-    if (pQuery->intervalTime == 0) {
+    if (!isIntervalQuery(pQuery)) {
       setExecutionContext(pQInfo, pTableQueryInfo, pTableDataInfo->tableIndex, pTableDataInfo->groupIdx, nextKey);
     } else {  // interval query
       setIntervalQueryRange(pTableQueryInfo, pQInfo, nextKey);
       int32_t ret = setAdditionalInfo(pQInfo, pTableDataInfo->tableIndex, pTableQueryInfo);
+      
       if (ret != TSDB_CODE_SUCCESS) {
-        //        pQInfo->killed = 1;
-        return;
+        pQInfo->code = ret;
+        return taosGetTimestampMs() - st;
       }
     }
 
-    //    stableApplyFunctionsOnBlock_(pSupporter, pTableDataInfo, &blockInfo, pStatis, pDataBlock, searchFn);
+    stableApplyFunctionsOnBlock(pRuntimeEnv, pTableDataInfo, &blockInfo, pStatis, pDataBlock, binarySearchForKey);
   }
+  
+  int64_t et = taosGetTimestampMs();
+  return et - st;
 }
 
 static bool multimeterMultioutputHelper(SQInfo *pQInfo, bool *dataInDisk, bool *dataInCache, int32_t index,
@@ -4499,7 +4469,7 @@ static int64_t doCheckMetersInGroup(SQInfo *pQInfo, int32_t index, int32_t start
   pointInterpSupporterSetData(pQInfo, &pointInterpSupporter);
   pointInterpSupporterDestroy(&pointInterpSupporter);
 
-  vnodeScanAllData(pRuntimeEnv);
+  scanAllDataBlocks(pRuntimeEnv);
 
   // first/last_row query, do not invoke the finalize for super table query
   doFinalizeResult(pRuntimeEnv);
@@ -4525,9 +4495,10 @@ static int64_t doCheckMetersInGroup(SQInfo *pQInfo, int32_t index, int32_t start
  */
 static void vnodeSTableSeqProcessor(SQInfo *pQInfo) {
   SQueryRuntimeEnv *pRuntimeEnv = &pQInfo->runtimeEnv;
-
-#if 0
   SQuery* pQuery = pRuntimeEnv->pQuery;
+  setQueryStatus(pQuery, QUERY_COMPLETED);
+  
+#if 0
 //  tSidSet *pTableIdList = pSupporter->pSidSet;
   
   int32_t vid = getMeterObj(pSupporter->pMetersHashTable, pMeterSidExtInfo[0]->sid)->vnode;
@@ -4679,7 +4650,7 @@ static void vnodeSTableSeqProcessor(SQInfo *pQInfo) {
         }
       }
       
-      vnodeScanAllData(pRuntimeEnv);
+      scanAllDataBlocks(pRuntimeEnv);
       
       pQuery->size = getNumOfResult(pRuntimeEnv);
       doSkipResults(pRuntimeEnv);
@@ -4778,95 +4749,85 @@ static void vnodeSTableSeqProcessor(SQInfo *pQInfo) {
 #endif
 }
 
-static void doOrderedScan(SQInfo *pQInfo) {
-  SQuery *pQuery = &pQInfo->runtimeEnv.pQuery;
-#if 0
-//  if (pQInfo->runtimeEnv. == NULL) {
-//    pSupporter->pMeterDataInfo = calloc(pSupporter->pSidSet->numOfTables, sizeof(STableDataInfo));
-//  }
-  
-  STableIdInfo **pMeterSidExtInfo = pSupporter->pMeterSidExtInfo;
+static void createTableDataInfo(SQInfo* pQInfo) {
+  SQuery* pQuery = pQInfo->runtimeEnv.pQuery;
   
-  tSidSet* pSidset = pSupporter->pSidSet;
-  int32_t groupId = 0;
+  // todo make sure the table are added the reference count to gauranteed that all involved tables are valid
+  int32_t numOfTables = taosArrayGetSize(pQInfo->pTableIdList);
   
-  for (int32_t i = 0; i < pSidset->numOfTables; ++i) {  // load all meter meta info
-    SMeterObj *pMeterObj = getMeterObj(pSupporter->pMetersHashTable, pMeterSidExtInfo[i]->sid);
-    if (pMeterObj == NULL) {
-      dError("QInfo:%p failed to find required sid:%d", pQInfo, pMeterSidExtInfo[i]->sid);
-      continue;
+  if (pQInfo->pTableDataInfo == NULL) {
+    pQInfo->pTableDataInfo = (STableDataInfo *)calloc(1, sizeof(STableDataInfo) * numOfTables);
+    if (pQInfo->pTableDataInfo == NULL) {
+      dError("QInfo:%p failed to allocate memory, %s", pQInfo, strerror(errno));
+      pQInfo->code = -TSDB_CODE_SERV_OUT_OF_MEMORY;
+      return;
     }
     
-    if (i >= pSidset->starterPos[groupId + 1]) {
-      groupId += 1;
+    int32_t groupId = 0;
+    for (int32_t i = 0; i < numOfTables; ++i) {  // load all meter meta info
+      STableId *id = taosArrayGet(pQInfo->pTableIdList, i);
+      STableDataInfo *pInfo = &pQInfo->pTableDataInfo[i];
+      
+      setTableDataInfo(pInfo, i, groupId);
+      pInfo->pTableQInfo = createTableQueryInfo(&pQInfo->runtimeEnv, id->tid, pQuery->window);
     }
-    
-    STableDataInfo *pOneMeterDataInfo = &pSupporter->pMeterDataInfo[i];
-    assert(pOneMeterDataInfo->pMeterObj == NULL);
-    
-    setMeterDataInfo(pOneMeterDataInfo, pMeterObj, i, groupId);
-    pOneMeterDataInfo->pTableQInfo = createMeterQueryInfo(pSupporter, pMeterObj->sid, pQuery->skey, pQuery->ekey);
   }
-  
-  queryOnDataBlocks(pQInfo, pSupporter->pMeterDataInfo);
-  if (pQInfo->code != TSDB_CODE_SUCCESS) {
-    return;
-  }
-#endif
 }
 
-static void setupMeterQueryInfoForSupplementQuery(SQInfo *pQInfo) {
+static void prepareQueryInfoForReverseScan(SQInfo *pQInfo) {
   SQuery *pQuery = pQInfo->runtimeEnv.pQuery;
-
-  int32_t num = taosHashGetSize(pQInfo->pTableIdList);
-  for (int32_t i = 0; i < num; ++i) {
-    //    STableQueryInfo *pTableQueryInfo = pSupporter->pMeterDataInfo[i].pTableQInfo;
-    //    changeMeterQueryInfoForSuppleQuery(pQuery, pTableQueryInfo, pSupporter->rawSKey, pSupporter->rawEKey);
+  size_t numOfTables = taosArrayGetSize(pQInfo->pTableIdList);
+  
+  for (int32_t i = 0; i < numOfTables; ++i) {
+    STableQueryInfo *pTableQueryInfo = pQInfo->pTableDataInfo[i].pTableQInfo;
+    changeMeterQueryInfoForSuppleQuery(pQuery, pTableQueryInfo);
   }
 }
 
-static void doMultiMeterSupplementaryScan(SQInfo *pQInfo) {
-  SQueryRuntimeEnv *pRuntimeEnv = &pQInfo->runtimeEnv;
-  SQuery *          pQuery = pRuntimeEnv->pQuery;
-
-  if (!needSupplementaryScan(pQuery)) {
-    dTrace("QInfo:%p no need to do supplementary scan, query completed", pQInfo);
-    return;
-  }
-
+static void doSaveContext(SQInfo* pQInfo) {
+  SQueryRuntimeEnv* pRuntimeEnv = &pQInfo->runtimeEnv;
+  SQuery* pQuery = pRuntimeEnv->pQuery;
+  
   SET_SUPPLEMENT_SCAN_FLAG(pRuntimeEnv);
-  //  disableFunctForSuppleScan(pSupporter, pQuery->order.order);
-
+  disableFuncForReverseScan(pQInfo, pQuery->order.order);
+  
   if (pRuntimeEnv->pTSBuf != NULL) {
     pRuntimeEnv->pTSBuf->cur.order = pRuntimeEnv->pTSBuf->cur.order ^ 1u;
   }
-
-#if 0
-  SWAP(pSupporter->rawSKey, pSupporter->rawEKey, TSKEY);
-  setupMeterQueryInfoForSupplementQuery(pSupporter);
-  
-  int64_t st = taosGetTimestampMs();
   
-  doOrderedScan(pQInfo);
-  
-  int64_t et = taosGetTimestampMs();
-  dTrace("QInfo:%p supplementary scan completed, elapsed time: %lldms", pQInfo, et - st);
+  SWAP(pQuery->window.skey, pQuery->window.ekey, TSKEY);
+  prepareQueryInfoForReverseScan(pQInfo);
+}
+
+static void doRestoreContext(SQInfo* pQInfo) {
+  SQueryRuntimeEnv* pRuntimeEnv = &pQInfo->runtimeEnv;
+  SQuery* pQuery = pRuntimeEnv->pQuery;
   
-  /*
-   * restore the env
-   * the meter query info is not reset to the original state
-   */
-  SWAP(pSupporter->rawSKey, pSupporter->rawEKey, TSKEY);
-  enableFunctForMasterScan(pRuntimeEnv, pQuery->order.order);
+  SWAP(pQuery->window.skey, pQuery->window.ekey, TSKEY);
   
   if (pRuntimeEnv->pTSBuf != NULL) {
     pRuntimeEnv->pTSBuf->cur.order = pRuntimeEnv->pTSBuf->cur.order ^ 1;
   }
-#endif
+  
+  enableFuncForForwardScan(pRuntimeEnv, pQuery->order.order);
   SET_MASTER_SCAN_FLAG(pRuntimeEnv);
 }
 
-static void vnodeMultiMeterQueryProcessor(SQInfo *pQInfo) {
+static void doCloseAllTimeWindowAfterScan(SQInfo* pQInfo) {
+  SQuery* pQuery = pQInfo->runtimeEnv.pQuery;
+  size_t numOfTables = taosArrayGetSize(pQInfo->pTableIdList);
+  
+  if (isIntervalQuery(pQuery)) {
+    for (int32_t i = 0; i < numOfTables; ++i) {
+      STableQueryInfo *pTableQueryInfo = pQInfo->pTableDataInfo[i].pTableQInfo;
+      closeAllTimeWindow(&pTableQueryInfo->windowResInfo);
+    }
+  } else {  // close results for group result
+    closeAllTimeWindow(&pQInfo->runtimeEnv.windowResInfo);
+  }
+}
+
+static void multiTableQueryProcess(SQInfo *pQInfo) {
   SQueryRuntimeEnv *pRuntimeEnv = &pQInfo->runtimeEnv;
   SQuery *          pQuery = pRuntimeEnv->pQuery;
 
@@ -4875,7 +4836,7 @@ static void vnodeMultiMeterQueryProcessor(SQInfo *pQInfo) {
      * if the subgroupIdx > 0, the query process must be completed yet, we only need to
      * copy the data into output buffer
      */
-    if (pQuery->intervalTime > 0) {
+    if (isIntervalQuery(pQuery)) {
       copyResToQueryResultBuf(pQInfo, pQuery);
 
 #ifdef _DEBUG_VIEW
@@ -4894,46 +4855,50 @@ static void vnodeMultiMeterQueryProcessor(SQInfo *pQInfo) {
     dTrace("QInfo:%p current:%lldd, total:%lldd", pQInfo, pQuery->rec.size, pQuery->rec.total);
     return;
   }
-#if 0
-  pSupporter->pMeterDataInfo = (STableDataInfo *)calloc(1, sizeof(STableDataInfo) * pSupporter->numOfMeters);
-  if (pSupporter->pMeterDataInfo == NULL) {
-    dError("QInfo:%p failed to allocate memory, %s", pQInfo, strerror(errno));
-    pQInfo->code = -TSDB_CODE_SERV_OUT_OF_MEMORY;
-    return;
-  }
   
-  dTrace("QInfo:%p query start, qrange:%" PRId64 "-%" PRId64 ", order:%d, group:%d", pQInfo, pSupporter->rawSKey,
-         pSupporter->rawEKey, pQuery->order.order, pSupporter->pSidSet->numOfSubSet);
+  dTrace("QInfo:%p query start, qrange:%" PRId64 "-%" PRId64 ", order:%d, forward scan start", pQInfo, pQuery->window.skey,
+         pQuery->window.ekey, pQuery->order.order);
   
-  dTrace("QInfo:%p main query scan start", pQInfo);
-  int64_t st = taosGetTimestampMs();
-  doOrderedScan(pQInfo);
+  // create the query support structures
+  createTableDataInfo(pQInfo);
   
-  int64_t et = taosGetTimestampMs();
-  dTrace("QInfo:%p main scan completed, elapsed time: %lldms, supplementary scan start, order:%d", pQInfo, et - st,
+  // do check all qualified data blocks
+  int64_t el = queryOnDataBlocks(pQInfo);
+  dTrace("QInfo:%p forward scan completed, elapsed time: %lldms, reversed scan start, order:%d", pQInfo, el,
          pQuery->order.order ^ 1u);
   
-  if (pQuery->intervalTime > 0) {
-    for (int32_t i = 0; i < pSupporter->numOfMeters; ++i) {
-      STableQueryInfo *pTableQueryInfo = pSupporter->pMeterDataInfo[i].pTableQInfo;
-      closeAllTimeWindow(&pTableQueryInfo->windowResInfo);
-    }
-  } else {  // close results for group result
-    closeAllTimeWindow(&pRuntimeEnv->windowResInfo);
+  // query error occurred or query is killed, abort current execution
+  if (pQInfo->code != TSDB_CODE_SUCCESS || isQueryKilled(pQInfo)) {
+    dTrace("QInfo:%p query killed or error occurred, code:%d, abort", pQInfo, pQInfo->code);
+    return;
   }
   
-  doMultiMeterSupplementaryScan(pQInfo);
+  // close all time window results
+  doCloseAllTimeWindowAfterScan(pQInfo);
   
-  if (isQueryKilled(pQInfo)) {
-    dTrace("QInfo:%p query killed, abort", pQInfo);
+  if (needReverseScan(pQuery)) {
+    doSaveContext(pQInfo);
+    
+    el = queryOnDataBlocks(pQInfo);
+    dTrace("QInfo:%p reversed scan completed, elapsed time: %lldms", pQInfo, el);
+    
+    doRestoreContext(pQInfo);
+  } else {
+    dTrace("QInfo:%p no need to do reversed scan, query completed", pQInfo);
+  }
+  
+  setQueryStatus(pQuery, QUERY_COMPLETED);
+  
+  if (pQInfo->code != TSDB_CODE_SUCCESS || isQueryKilled(pQInfo)) {
+    dTrace("QInfo:%p query killed or error occurred, code:%d, abort", pQInfo, pQInfo->code);
     return;
   }
   
-  if (pQuery->intervalTime > 0 || isSumAvgRateQuery(pQuery)) {
-    assert(pSupporter->subgroupIdx == 0 && pSupporter->numOfGroupResultPages == 0);
+  if (isIntervalQuery(pQuery) || isSumAvgRateQuery(pQuery)) {
+//    assert(pSupporter->subgroupIdx == 0 && pSupporter->numOfGroupResultPages == 0);
     
-    if (mergeMetersResultToOneGroups(pSupporter) == TSDB_CODE_SUCCESS) {
-      copyResToQueryResultBuf(pSupporter, pQuery);
+    if (mergeResultsToGroup(pQInfo) == TSDB_CODE_SUCCESS) {
+      copyResToQueryResultBuf(pQInfo, pQuery);
 
 #ifdef _DEBUG_VIEW
       displayInterResult(pQuery->sdata, pQuery, pQuery->sdata[0]->len);
@@ -4944,10 +4909,7 @@ static void vnodeMultiMeterQueryProcessor(SQInfo *pQInfo) {
   }
   
   // handle the limitation of output buffer
-  pQInfo->size += pQuery->size;
-  dTrace("QInfo:%p points returned:%d, totalRead:%d totalReturn:%d", pQInfo, pQuery->size, pQInfo->size,
-         pQInfo->pointsReturned);
-#endif
+  dTrace("QInfo:%p points returned:%d, total:%d", pQInfo, pQuery->rec.size, pQuery->rec.total);
 }
 
 /*
@@ -4960,7 +4922,7 @@ static void tableFixedOutputProcessor(SQInfo *pQInfo) {
   SQueryRuntimeEnv *pRuntimeEnv = &pQInfo->runtimeEnv;
   SQuery *          pQuery = pRuntimeEnv->pQuery;
 
-  vnodeScanAllData(pRuntimeEnv);
+  scanAllDataBlocks(pRuntimeEnv);
   doFinalizeResult(pRuntimeEnv);
 
   if (isQueryKilled(pQInfo)) {
@@ -4993,7 +4955,7 @@ static void tableMultiOutputProcessor(SQInfo *pQInfo) {
   }
 
   while (1) {
-    vnodeScanAllData(pRuntimeEnv);
+    scanAllDataBlocks(pRuntimeEnv);
     doFinalizeResult(pRuntimeEnv);
 
     if (isQueryKilled(pQInfo)) {
@@ -5039,7 +5001,7 @@ static void tableIntervalProcessImpl(SQueryRuntimeEnv *pRuntimeEnv) {
 
   while (1) {
     initCtxOutputBuf(pRuntimeEnv);
-    vnodeScanAllData(pRuntimeEnv);
+    scanAllDataBlocks(pRuntimeEnv);
 
     if (isQueryKilled(GET_QINFO_ADDR(pRuntimeEnv))) {
       return;
@@ -5076,7 +5038,7 @@ static void tableIntervalProcessor(SQInfo *pQInfo) {
   while (1) {
     tableIntervalProcessImpl(pRuntimeEnv);
 
-    if (pQuery->intervalTime > 0) {
+    if (isIntervalQuery(pQuery)) {
       pQInfo->subgroupIdx = 0;  // always start from 0
       pQuery->rec.size = 0;
       copyFromWindowResToSData(pQInfo, pRuntimeEnv->windowResInfo.pResult);
@@ -5213,15 +5175,15 @@ static void singleTableQueryImpl(SQInfo* pQInfo) {
   sem_post(&pQInfo->dataReady);
 }
 
-void multiTableQueryImpl(SQInfo* pQInfo) {
+static void multiTableQueryImpl(SQInfo* pQInfo) {
   SQuery* pQuery = pQInfo->runtimeEnv.pQuery;
   pQuery->rec.size = 0;
   
   int64_t st = taosGetTimestampUs();
   
-  if (pQuery->intervalTime > 0 ||
+  if (isIntervalQuery(pQuery) ||
       (isFixedOutputQuery(pQuery) && (!isPointInterpoQuery(pQuery)) && !isGroupbyNormalCol(pQuery->pGroupbyExpr))) {
-    vnodeMultiMeterQueryProcessor(pQInfo);
+    multiTableQueryProcess(pQInfo);
   } else {
     assert((pQuery->checkBufferInLoop == 1 && pQuery->intervalTime == 0) || isPointInterpoQuery(pQuery) ||
         isGroupbyNormalCol(pQuery->pGroupbyExpr));
@@ -5242,29 +5204,6 @@ void multiTableQueryImpl(SQInfo* pQInfo) {
   sem_post(&pQInfo->dataReady);
 }
 
-void qTableQuery(SQInfo *pQInfo) {
-  if (pQInfo == NULL || pQInfo->signature != pQInfo) {
-    dTrace("%p freed abort query", pQInfo);
-    return;
-  }
-  
-  if (isQueryKilled(pQInfo)) {
-    dTrace("QInfo:%p it is already killed, abort", pQInfo);
-    return;
-  }
-  
-  dTrace("QInfo:%p query task is launched", pQInfo);
-  
-  int32_t numOfTables = taosArrayGetSize(pQInfo->pTableIdList);
-  if (numOfTables == 1) {
-    singleTableQueryImpl(pQInfo);
-  } else {
-    multiTableQueryImpl(pQInfo);
-  }
-  
-  //  vnodeDecRefCount(pQInfo);
-}
-
 static int32_t getColumnIndexInSource(SQueryTableMsg *pQueryMsg, SSqlFuncExprMsg *pExprMsg) {
   int32_t j = 0;
 
@@ -5284,7 +5223,7 @@ bool vnodeValidateExprColumnInfo(SQueryTableMsg *pQueryMsg, SSqlFuncExprMsg *pEx
   return j < pQueryMsg->numOfCols;
 }
 
-static int32_t validateQueryMeterMsg(SQueryTableMsg *pQueryMsg) {
+static int32_t validateQueryMsg(SQueryTableMsg *pQueryMsg) {
   if (pQueryMsg->intervalTime < 0) {
     dError("qmsg:%p illegal value of aggTimeInterval %" PRId64 "", pQueryMsg, pQueryMsg->intervalTime);
     return -1;
@@ -5316,14 +5255,16 @@ static int32_t validateQueryMeterMsg(SQueryTableMsg *pQueryMsg) {
 static char* createTableIdList(SQueryTableMsg* pQueryMsg, char* pMsg, SArray** pTableIdList) {
   assert(pQueryMsg->numOfTables > 0);
   
-  *pTableIdList = taosArrayInit(pQueryMsg->numOfTables, sizeof(STableIdInfo));
+  *pTableIdList = taosArrayInit(pQueryMsg->numOfTables, sizeof(STableId));
   
   STableIdInfo *pTableIdInfo = (STableIdInfo *)pMsg;
   pTableIdInfo->sid = htonl(pTableIdInfo->sid);
   pTableIdInfo->uid = htobe64(pTableIdInfo->uid);
   pTableIdInfo->key = htobe64(pTableIdInfo->key);
   
-  taosArrayPush(*pTableIdList, pTableIdInfo);
+  STableId id = {.uid = pTableIdInfo->uid, .tid = pTableIdInfo->sid};
+  taosArrayPush(*pTableIdList, &id);
+  
   pMsg += sizeof(STableIdInfo);
   
   for (int32_t j = 1; j < pQueryMsg->numOfTables; ++j) {
@@ -5349,7 +5290,7 @@ static char* createTableIdList(SQueryTableMsg* pQueryMsg, char* pMsg, SArray** p
  * @return
  */
 static int32_t convertQueryMsg(SQueryTableMsg *pQueryMsg, SArray **pTableIdList, SSqlFuncExprMsg ***pExpr,
-      wchar_t** tagCond, char** nameCond) {
+      wchar_t** tagCond) {
   pQueryMsg->numOfTables   = htonl(pQueryMsg->numOfTables);
 
   pQueryMsg->window.skey   = htobe64(pQueryMsg->window.skey);
@@ -5374,7 +5315,7 @@ static int32_t convertQueryMsg(SQueryTableMsg *pQueryMsg, SArray **pTableIdList,
   pQueryMsg->tsOrder       = htonl(pQueryMsg->tsOrder);
 
   // query msg safety check
-  if (validateQueryMeterMsg(pQueryMsg) != 0) {
+  if (validateQueryMsg(pQueryMsg) != 0) {
     return TSDB_CODE_INVALID_QUERY_MSG;
   }
 
@@ -5503,10 +5444,6 @@ static int32_t convertQueryMsg(SQueryTableMsg *pQueryMsg, SArray **pTableIdList,
     *tagCond = calloc(1, pQueryMsg->tagCondLen * TSDB_NCHAR_SIZE);
     memcpy(*tagCond, pMsg, pQueryMsg->tagCondLen * TSDB_NCHAR_SIZE);
   }
-  
-  if (pQueryMsg->nameCondLen > 0) {
-    *nameCond = strndup(pMsg, pQueryMsg->nameCondLen);
-  }
 
   dTrace("qmsg:%p query on %d meter(s), qrange:%" PRId64 "-%" PRId64 ", numOfGroupbyTagCols:%d, numOfTagCols:%d, "
          "timestamp order:%d, tags order:%d, tags order col:%d, numOfOutputCols:%d, numOfCols:%d, interval:%" PRId64
@@ -5895,7 +5832,18 @@ static SQInfo *createQInfoImpl(SQueryTableMsg *pQueryMsg, SSqlGroupbyExpr *pGrou
 
   pQuery->pos = -1;
   
-  dTrace("QInfo %p is allocated", pQInfo);
+  pQuery->window.skey = pQueryMsg->window.skey;
+  pQuery->window.ekey = pQueryMsg->window.ekey;
+  pQuery->lastKey     = pQuery->window.skey;
+  
+  if (sem_init(&pQInfo->dataReady, 0, 0) != 0) {
+    dError("QInfo:%p init dataReady sem failed, reason:%s", pQInfo, strerror(errno));
+    goto _clean_memory;
+  }
+  
+  vnodeParametersSafetyCheck(pQuery);
+  
+  dTrace("qmsg:%p create QInfo:%p, QInfo created", pQueryMsg, pQInfo);
   return pQInfo;
 
 _clean_memory:
@@ -5919,7 +5867,7 @@ _clean_memory:
   return NULL;
 }
 
-bool isQInfoValid(void *param) {
+static bool isValidQInfo(void *param) {
   SQInfo *pQInfo = (SQInfo *)param;
   if (pQInfo == NULL) {
     return false;
@@ -5933,11 +5881,51 @@ bool isQInfoValid(void *param) {
   return (sig == (uint64_t)pQInfo);
 }
 
-void vnodeFreeQInfo(SQInfo *pQInfo) {
-  if (!isQInfoValid(pQInfo)) {
-    return;
+static void freeQInfo(SQInfo *pQInfo);
+static int32_t initializeQInfo(SQueryTableMsg *pQueryMsg, void* tsdb, SQInfo *pQInfo, bool isSTable) {
+  int32_t code = TSDB_CODE_SUCCESS;
+  SQuery *pQuery = pQInfo->runtimeEnv.pQuery;
+  
+  STSBuf *pTSBuf = NULL;
+  if (pQueryMsg->tsLen > 0) {  // open new file to save the result
+    char *tsBlock = (char *)pQueryMsg + pQueryMsg->tsOffset;
+    pTSBuf = tsBufCreateFromCompBlocks(tsBlock, pQueryMsg->tsNumOfBlocks, pQueryMsg->tsLen, pQueryMsg->tsOrder);
+    
+    tsBufResetPos(pTSBuf);
+    tsBufNextPos(pTSBuf);
+  }
+  
+  // only the successful complete requries the sem_post/over = 1 operations.
+  if ((QUERY_IS_ASC_QUERY(pQuery) && (pQuery->window.skey > pQuery->window.ekey)) ||
+      (!QUERY_IS_ASC_QUERY(pQuery) && (pQuery->window.ekey > pQuery->window.skey))) {
+    dTrace("QInfo:%p no result in time range %" PRId64 "-%" PRId64 ", order %d", pQInfo, pQuery->window.skey,
+           pQuery->window.ekey, pQuery->order.order);
+    
+    sem_post(&pQInfo->dataReady);
+    setQueryStatus(pQuery, QUERY_COMPLETED);
+    return TSDB_CODE_SUCCESS;
+  }
+
+  // filter the qualified
+  if ((code = doInitializeQInfo(pQInfo, pTSBuf, tsdb, isSTable)) != TSDB_CODE_SUCCESS) {
+    goto _error;
   }
 
+  // dTrace("QInfo:%p set query flag and prepare runtime environment completed, ref:%d, wait for schedule", pQInfo,
+  //       pQInfo->refCount);
+  return code;
+
+_error:
+  // table query ref will be decrease during error handling
+  freeQInfo(pQInfo);
+  return code;
+}
+
+static void freeQInfo(SQInfo *pQInfo) {
+  if (!isValidQInfo(pQInfo)) {
+    return;
+  }
+  
   SQuery* pQuery = pQInfo->runtimeEnv.pQuery;
   setQueryKilled(pQInfo);
   
@@ -5945,7 +5933,7 @@ void vnodeFreeQInfo(SQInfo *pQInfo) {
   for (int32_t col = 0; col < pQuery->numOfOutputCols; ++col) {
     tfree(pQuery->sdata[col]);
   }
-
+  
   //  for (int col = 0; col < pQuery->numOfCols; ++col) {
   //    vnodeFreeColumnInfo(&pQuery->colList[col].data);
   //  }
@@ -5953,100 +5941,102 @@ void vnodeFreeQInfo(SQInfo *pQInfo) {
   //  if (pQuery->colList[0].colIdx != PRIMARYKEY_TIMESTAMP_COL_INDEX) {
   //    tfree(pQuery->tsData);
   //  }
-
+  
   sem_destroy(&(pQInfo->dataReady));
   vnodeQueryFreeQInfoEx(pQInfo);
-
+  
   for (int32_t i = 0; i < pQuery->numOfFilterCols; ++i) {
     SSingleColumnFilterInfo *pColFilter = &pQuery->pFilterInfo[i];
     if (pColFilter->numOfFilters > 0) {
       tfree(pColFilter->pFilters);
     }
   }
-
+  
   tfree(pQuery->pFilterInfo);
   tfree(pQuery->colList);
   tfree(pQuery->sdata);
-
+  
   if (pQuery->pSelectExpr != NULL) {
     for (int32_t i = 0; i < pQuery->numOfOutputCols; ++i) {
       SSqlBinaryExprInfo *pBinExprInfo = &pQuery->pSelectExpr[i].binExprInfo;
-
+      
       if (pBinExprInfo->numOfCols > 0) {
         tfree(pBinExprInfo->pReqColumns);
         tSQLBinaryExprDestroy(&pBinExprInfo->pBinExpr, NULL);
       }
     }
-
+    
     tfree(pQuery->pSelectExpr);
   }
-
+  
   if (pQuery->defaultVal != NULL) {
     tfree(pQuery->defaultVal);
   }
-
+  
   tfree(pQuery->pGroupbyExpr);
   tfree(pQuery);
-
+  
   dTrace("QInfo:%p QInfo is freed", pQInfo);
-
+  
   // destroy signature, in order to avoid the query process pass the object safety check
   memset(pQInfo, 0, sizeof(SQInfo));
   tfree(pQInfo);
 }
 
-static int32_t createQInfo(SQueryTableMsg *pQueryMsg, SSqlGroupbyExpr *pGroupbyExpr, SSqlFunctionExpr *pSqlExprs,
-                           SArray *pTableIdList, void* tsdb, SQInfo **pQInfo) {
-  int32_t code = TSDB_CODE_SUCCESS;
+static size_t getResultSize(SQInfo *pQInfo, int64_t *numOfRows) {
+  SQuery* pQuery = pQInfo->runtimeEnv.pQuery;
   
-  (*pQInfo) = createQInfoImpl(pQueryMsg, pGroupbyExpr, pSqlExprs, pTableIdList);
-  if ((*pQInfo) == NULL) {
-    code = TSDB_CODE_SERV_OUT_OF_MEMORY;
-    goto _error;
-  }
-
-  SQuery *pQuery = (*pQInfo)->runtimeEnv.pQuery;
-  dTrace("qmsg:%p create QInfo:%p, QInfo created", pQueryMsg, pQInfo);
-
-  pQuery->window.skey = pQueryMsg->window.skey;
-  pQuery->window.ekey = pQueryMsg->window.ekey;
-  pQuery->lastKey     = pQuery->window.skey;
-
-  if (sem_init(&(*pQInfo)->dataReady, 0, 0) != 0) {
-    dError("QInfo:%p init dataReady sem failed, reason:%s", pQInfo, strerror(errno));
-    code = TSDB_CODE_APP_ERROR;
-    goto _error;
-  }
-
-  vnodeParametersSafetyCheck(pQuery);
-
-  STSBuf *pTSBuf = NULL;
-  if (pQueryMsg->tsLen > 0) {  // open new file to save the result
-    char *tsBlock = (char *)pQueryMsg + pQueryMsg->tsOffset;
-    pTSBuf = tsBufCreateFromCompBlocks(tsBlock, pQueryMsg->tsNumOfBlocks, pQueryMsg->tsLen, pQueryMsg->tsOrder);
-
-    tsBufResetPos(pTSBuf);
-    tsBufNextPos(pTSBuf);
+  /*
+   * get the file size and set the numOfRows to be the file size, since for tsComp query,
+   * the returned row size is equalled to 1
+   * TODO handle the case that the file is too large to send back one time
+   */
+  if (isTSCompQuery(pQuery) && (*numOfRows) > 0) {
+    struct stat fstat;
+    if (stat(pQuery->sdata[0]->data, &fstat) == 0) {
+      *numOfRows = fstat.st_size;
+      return fstat.st_size;
+    } else {
+      dError("QInfo:%p failed to get file info, path:%s, reason:%s", pQInfo, pQuery->sdata[0]->data, strerror(errno));
+      return 0;
+    }
+  } else {
+    return pQuery->rowSize * (*numOfRows);
   }
+}
 
-  // filter the qualified
-  if ((code = initQInfo(*pQInfo, pTSBuf, tsdb)) != TSDB_CODE_SUCCESS) {
-    goto _error;
+static int32_t doDumpQueryResult(SQInfo *pQInfo, char *data) {
+  // the remained number of retrieved rows, not the interpolated result
+  SQuery *pQuery = pQInfo->runtimeEnv.pQuery;
+  
+  // load data from file to msg buffer
+  if (isTSCompQuery(pQuery)) {
+    int32_t fd = open(pQuery->sdata[0]->data, O_RDONLY, 0666);
+    
+    // make sure file exist
+    if (FD_VALID(fd)) {
+      size_t s = lseek(fd, 0, SEEK_END);
+      dTrace("QInfo:%p ts comp data return, file:%s, size:%zu", pQInfo, pQuery->sdata[0]->data, s);
+      
+      lseek(fd, 0, SEEK_SET);
+      read(fd, data, s);
+      close(fd);
+      
+      unlink(pQuery->sdata[0]->data);
+    } else {
+      dError("QInfo:%p failed to open tmp file to send ts-comp data to client, path:%s, reason:%s", pQInfo,
+             pQuery->sdata[0]->data, strerror(errno));
+    }
+  } else {
+    doCopyQueryResultToMsg(pQInfo, pQuery->rec.size, data);
   }
-
-  //  if (pQInfo->over == 1) {
-  //    vnodeAddRefCount(pQInfo);  // for retrieve procedure
-  //    return pQInfo;
-  //  }
-
-  // dTrace("QInfo:%p set query flag and prepare runtime environment completed, ref:%d, wait for schedule", pQInfo,
-  //       pQInfo->refCount);
-  return code;
-
-_error:
-  // table query ref will be decrease during error handling
-  vnodeFreeQInfo(*pQInfo);
-  return code;
+  
+  pQuery->rec.total += pQuery->rec.size;
+  dTrace("QInfo:%p current:%d, total:%d", pQInfo, pQuery->rec.size, pQuery->rec.total);
+  
+  return TSDB_CODE_SUCCESS;
+  
+  // todo if interpolation exists, the result may be dump to client by several rounds
 }
 
 int32_t qCreateQueryInfo(void* tsdb, SQueryTableMsg *pQueryMsg, SQInfo **pQInfo) {
@@ -6057,9 +6047,7 @@ int32_t qCreateQueryInfo(void* tsdb, SQueryTableMsg *pQueryMsg, SQInfo **pQInfo)
   SArray *pTableIdList = NULL;
   SSqlFuncExprMsg** pExprMsg = NULL;
   wchar_t* tagCond = NULL;
-  char* nameCond = NULL;
-  
-  if ((code = convertQueryMsg(pQueryMsg, &pTableIdList, &pExprMsg, &tagCond, &nameCond)) != TSDB_CODE_SUCCESS) {
+  if ((code = convertQueryMsg(pQueryMsg, &pTableIdList, &pExprMsg, &tagCond)) != TSDB_CODE_SUCCESS) {
     return code;
   }
 
@@ -6088,7 +6076,10 @@ int32_t qCreateQueryInfo(void* tsdb, SQueryTableMsg *pQueryMsg, SQInfo **pQInfo)
   
   // super table query
   SArray* res = NULL;
+  bool isSTableQuery = false;
   if ((pQueryMsg->queryType & TSDB_QUERY_TYPE_STABLE_QUERY) != 0) {
+    isSTableQuery = true;
+    
     STableId* id = taosArrayGet(pTableIdList, 0);
     id->uid = -1;
     
@@ -6101,8 +6092,13 @@ int32_t qCreateQueryInfo(void* tsdb, SQueryTableMsg *pQueryMsg, SQInfo **pQInfo)
     res = pTableIdList;
   }
   
-  code = createQInfo(pQueryMsg, pGroupbyExpr, pExprs, res, tsdb, pQInfo);
-
+  (*pQInfo) = createQInfoImpl(pQueryMsg, pGroupbyExpr, pExprs, res);
+  if ((*pQInfo) == NULL) {
+    code = TSDB_CODE_SERV_OUT_OF_MEMORY;
+  }
+  
+  code = initializeQInfo(pQueryMsg, tsdb, *pQInfo, isSTableQuery);
+  
 _query_over:
   if (code != TSDB_CODE_SUCCESS) {
     taosArrayDestroy(pTableIdList);
@@ -6126,8 +6122,31 @@ _query_over:
   return TSDB_CODE_SUCCESS;
 }
 
+void qTableQuery(SQInfo *pQInfo) {
+  if (pQInfo == NULL || pQInfo->signature != pQInfo) {
+    dTrace("%p freed abort query", pQInfo);
+    return;
+  }
+  
+  if (isQueryKilled(pQInfo)) {
+    dTrace("QInfo:%p it is already killed, abort", pQInfo);
+    return;
+  }
+  
+  dTrace("QInfo:%p query task is launched", pQInfo);
+  
+  int32_t numOfTables = taosArrayGetSize(pQInfo->pTableIdList);
+  if (numOfTables == 1) {
+    singleTableQueryImpl(pQInfo);
+  } else {
+    multiTableQueryImpl(pQInfo);
+  }
+  
+  //  vnodeDecRefCount(pQInfo);
+}
+
 int32_t qRetrieveQueryResultInfo(SQInfo *pQInfo) {
-  if (pQInfo == NULL || !isQInfoValid(pQInfo)) {
+  if (pQInfo == NULL || !isValidQInfo(pQInfo)) {
     return TSDB_CODE_INVALID_QHANDLE;
   }
   
@@ -6148,62 +6167,6 @@ int32_t qRetrieveQueryResultInfo(SQInfo *pQInfo) {
   return (pQInfo->code >= 0)? pQInfo->code:(-pQInfo->code);
 }
 
-static size_t getResultSize(SQInfo *pQInfo, int64_t *numOfRows) {
-  SQuery* pQuery = pQInfo->runtimeEnv.pQuery;
-  
-  /*
-   * get the file size and set the numOfRows to be the file size, since for tsComp query,
-   * the returned row size is equalled to 1
-   * TODO handle the case that the file is too large to send back one time
-   */
-  if (isTSCompQuery(pQuery) && (*numOfRows) > 0) {
-    struct stat fstat;
-    if (stat(pQuery->sdata[0]->data, &fstat) == 0) {
-      *numOfRows = fstat.st_size;
-      return fstat.st_size;
-    } else {
-      dError("QInfo:%p failed to get file info, path:%s, reason:%s", pQInfo, pQuery->sdata[0]->data, strerror(errno));
-      return 0;
-    }
-  } else {
-    return pQuery->rowSize * (*numOfRows);
-  }
-}
-
-static int32_t doDumpQueryResult(SQInfo *pQInfo, char *data) {
-  // the remained number of retrieved rows, not the interpolated result
-  SQuery *pQuery = pQInfo->runtimeEnv.pQuery;
-  
-  // load data from file to msg buffer
-  if (isTSCompQuery(pQuery)) {
-    int32_t fd = open(pQuery->sdata[0]->data, O_RDONLY, 0666);
-    
-    // make sure file exist
-    if (FD_VALID(fd)) {
-      size_t s = lseek(fd, 0, SEEK_END);
-      dTrace("QInfo:%p ts comp data return, file:%s, size:%zu", pQInfo, pQuery->sdata[0]->data, s);
-      
-      lseek(fd, 0, SEEK_SET);
-      read(fd, data, s);
-      close(fd);
-      
-      unlink(pQuery->sdata[0]->data);
-    } else {
-      dError("QInfo:%p failed to open tmp file to send ts-comp data to client, path:%s, reason:%s", pQInfo,
-             pQuery->sdata[0]->data, strerror(errno));
-    }
-  } else {
-    doCopyQueryResultToMsg(pQInfo, pQuery->rec.size, data);
-  }
-  
-  pQuery->rec.total += pQuery->rec.size;
-  dTrace("QInfo:%p current:%d, total:%d", pQInfo, pQuery->rec.size, pQuery->rec.total);
-  
-  return TSDB_CODE_SUCCESS;
-  
-  // todo if interpolation exists, the result may be dump to client by several rounds
-}
-
 bool qHasMoreResultsToRetrieve(SQInfo* pQInfo) {
   if (pQInfo == NULL || pQInfo->signature != pQInfo || pQInfo->code != TSDB_CODE_SUCCESS) {
     return false;
@@ -6222,7 +6185,7 @@ bool qHasMoreResultsToRetrieve(SQInfo* pQInfo) {
 }
 
 int32_t qDumpRetrieveResult(SQInfo *pQInfo, SRetrieveTableRsp** pRsp, int32_t* contLen) {
-  if (pQInfo == NULL || !isQInfoValid(pQInfo)) {
+  if (pQInfo == NULL || !isValidQInfo(pQInfo)) {
     return TSDB_CODE_INVALID_QHANDLE;
   }
   
@@ -6251,7 +6214,7 @@ int32_t qDumpRetrieveResult(SQInfo *pQInfo, SRetrieveTableRsp** pRsp, int32_t* c
   
   if (isQueryKilled(pQInfo) || Q_STATUS_EQUAL(pQuery->status, QUERY_OVER)) {
     (*pRsp)->completed = 1; // notify no more result to client
-    vnodeFreeQInfo(pQInfo);
+    freeQInfo(pQInfo);
   }
   
   return code;
diff --git a/src/query/tests/CMakeLists.txt b/src/query/tests/CMakeLists.txt
new file mode 100644
index 0000000000000000000000000000000000000000..0ae86007568d3d7a00ba6f7b147ac5f0d00ee74a
--- /dev/null
+++ b/src/query/tests/CMakeLists.txt
@@ -0,0 +1,15 @@
+CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
+PROJECT(TDengine)
+
+FIND_PATH(HEADER_GTEST_INCLUDE_DIR gtest.h /usr/include/gtest /usr/local/include/gtest)
+FIND_LIBRARY(LIB_GTEST_STATIC_DIR libgtest.a /usr/lib/ /usr/local/lib)
+
+IF (HEADER_GTEST_INCLUDE_DIR AND LIB_GTEST_STATIC_DIR)
+    MESSAGE(STATUS "gTest library found, build unit test")
+
+    INCLUDE_DIRECTORIES(${HEADER_GTEST_INCLUDE_DIR})
+    AUX_SOURCE_DIRECTORY(${CMAKE_CURRENT_SOURCE_DIR} SOURCE_LIST)
+
+    ADD_EXECUTABLE(queryTest ${SOURCE_LIST})
+    TARGET_LINK_LIBRARIES(queryTest taos query gtest pthread)
+ENDIF()
\ No newline at end of file
diff --git a/src/query/tests/histogramTest.cpp b/src/query/tests/histogramTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..c23f0f59241d7bbc7527f7fe332fe97b666acbcc
--- /dev/null
+++ b/src/query/tests/histogramTest.cpp
@@ -0,0 +1,121 @@
+#include <gtest/gtest.h>
+#include <sys/time.h>
+#include <cassert>
+#include <iostream>
+
+#include "taos.h"
+#include "tsdb.h"
+
+#include "tstoken.h"
+#include "tutil.h"
+
+#include "qhistogram.h"
+
+/* test validate the names for table/database */
+TEST(testCase, histogram_binary_search) {
+  SHistogramInfo* pHisto = tHistogramCreate(MAX_HISTOGRAM_BIN);
+
+  pHisto->numOfEntries = 10;
+  for (int32_t i = 0; i < 10; ++i) {
+    pHisto->elems[i].num = 1;
+    pHisto->elems[i].val = i;
+  }
+
+  int32_t idx = vnodeHistobinarySearch(pHisto->elems, pHisto->numOfEntries, 1);
+  assert(idx == 1);
+
+  idx = vnodeHistobinarySearch(pHisto->elems, pHisto->numOfEntries, 9);
+  assert(idx == 9);
+
+  idx = vnodeHistobinarySearch(pHisto->elems, pHisto->numOfEntries, 20);
+  assert(idx == 10);
+
+  idx = vnodeHistobinarySearch(pHisto->elems, pHisto->numOfEntries, -1);
+  assert(idx == 0);
+
+  idx = vnodeHistobinarySearch(pHisto->elems, pHisto->numOfEntries, 3.9);
+  assert(idx == 4);
+
+  free(pHisto);
+}
+
+TEST(testCase, histogram_add) {
+  SHistogramInfo* pHisto = NULL;
+
+  /**
+   * use arrayList, elapsed time is:
+   * before:
+   * 10,000,000  45sec, bin:1000 (-O0) / 17sec. bin:1000, (-O3)
+   *
+   * after:
+   *
+   */
+  struct timeval systemTime;
+  gettimeofday(&systemTime, NULL);
+  int64_t st =
+      (int64_t)systemTime.tv_sec * 1000L + (uint64_t)systemTime.tv_usec / 1000;
+  for (int32_t i = 0; i < 10000; ++i) {
+    tHistogramAdd(&pHisto, i);
+    //        tHistogramPrint(pHisto);
+  }
+  //
+  gettimeofday(&systemTime, NULL);
+  int64_t et =
+      (int64_t)systemTime.tv_sec * 1000L + (uint64_t)systemTime.tv_usec / 1000;
+  printf("total elapsed time: %ld\n", et - st);
+
+  printf("elements: %d, slot:%d \n", pHisto->numOfElems, pHisto->numOfEntries);
+  tHistogramPrint(pHisto);
+
+  printf("%ld\n", tHistogramSum(pHisto, 1.5));
+  printf("%ld\n", tHistogramSum(pHisto, 2));
+  printf("%ld\n", tHistogramSum(pHisto, 3));
+  printf("%ld\n", tHistogramSum(pHisto, 4));
+  printf("%ld\n", tHistogramSum(pHisto, 5));
+  printf("%ld\n", tHistogramSum(pHisto, 6));
+
+  for (int32_t i = 399; i < 400; ++i) {
+    printf("val:%d, %ld\n", i, tHistogramSum(pHisto, i));
+  }
+
+  double ratio[] = {0 / 100, 20.0 / 100, 88.0 / 100, 100 / 100};
+  double* res = tHistogramUniform(pHisto, ratio, 4);
+  for (int32_t i = 0; i < 4; ++i) {
+    printf("%f\n", res[i]);
+  }
+
+  SHistogramInfo* pHisto1 = NULL;
+  for (int32_t i = (90000 - 1); i >= 80000; --i) {
+    tHistogramAdd(&pHisto1, i);
+  }
+  tHistogramPrint(pHisto1);
+
+  SHistogramInfo* pRes = tHistogramMerge(pHisto1, pHisto, MAX_HISTOGRAM_BIN);
+  assert(pRes->numOfElems == pHisto->numOfElems + pHisto1->numOfElems);
+  tHistogramPrint(pRes);
+
+  tHistogramDestroy(&pHisto);
+  tHistogramDestroy(&pHisto1);
+  tHistogramDestroy(&pRes);
+  free(res);
+}
+
+TEST(testCase, heapsort) {
+  //    int32_t num = 20;
+  //
+  //    SHeapEntry* pEntry = tHeapCreate(num);
+  //
+  //    for(int32_t i=0; i<num; ++i) {
+  //        pEntry[i].val = num - 1 - i;
+  //    }
+  //
+  //    tHeapSort(pEntry, num);
+  //
+  //    for(int32_t i=0; i<num; ++i) {
+  //        printf("%lf, ", pEntry[i].val);
+  //    }
+  //
+  //    printf("\n");
+  //
+  //    free(pEntry);
+}
diff --git a/src/query/tests/patternMatchTest.cpp b/src/query/tests/patternMatchTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..bca27ff42f6274a2801c75d55aa3c8ad64931b4a
--- /dev/null
+++ b/src/query/tests/patternMatchTest.cpp
@@ -0,0 +1,74 @@
+#include <gtest/gtest.h>
+#include <sys/time.h>
+#include <cassert>
+#include <iostream>
+
+#include "tsqlfunction.h"
+
+TEST(testCase, patternMatchTest) {
+  SPatternCompareInfo info = PATTERN_COMPARE_INFO_INITIALIZER;
+
+  const char* str = "abcdef";
+  int32_t ret = patternMatch("a%b%", str, strlen(str), &info);
+  EXPECT_EQ(ret, TSDB_PATTERN_MATCH);
+
+  str = "tm01";
+  ret = patternMatch("tm__", str, strlen(str), &info);
+  EXPECT_EQ(ret, TSDB_PATTERN_MATCH);
+
+  str = "tkm1";
+  ret = patternMatch("t%m1", str, strlen(str), &info);
+  EXPECT_EQ(ret, TSDB_PATTERN_MATCH);
+
+  str = "tkm1";
+  ret = patternMatch("%m1", str, strlen(str), &info);
+  EXPECT_EQ(ret, TSDB_PATTERN_MATCH);
+
+  str = "";
+  ret = patternMatch("%_", str, strlen(str), &info);
+  EXPECT_EQ(ret, TSDB_PATTERN_NOWILDCARDMATCH);
+
+  str = "1";
+  ret = patternMatch("%__", str, strlen(str), &info);
+  EXPECT_EQ(ret, TSDB_PATTERN_NOWILDCARDMATCH);
+
+  str = "";
+  ret = patternMatch("%", str, strlen(str), &info);
+  EXPECT_EQ(ret, TSDB_PATTERN_MATCH);
+
+  str = " ";
+  ret = patternMatch("_", str, strlen(str), &info);
+  EXPECT_EQ(ret, TSDB_PATTERN_MATCH);
+
+  str = "!";
+  ret = patternMatch("%_", str, strlen(str), &info);
+  EXPECT_EQ(ret, TSDB_PATTERN_MATCH);
+
+  str = "abcdefg";
+  ret = patternMatch("abc%fg", str, strlen(str), &info);
+  EXPECT_EQ(ret, TSDB_PATTERN_MATCH);
+
+  str = "abcdefgabcdeju";
+  ret = patternMatch("abc%fg", str, 7, &info);
+  EXPECT_EQ(ret, TSDB_PATTERN_MATCH);
+
+  str = "abcdefgabcdeju";
+  ret = patternMatch("abc%f_", str, 6, &info);
+  EXPECT_EQ(ret, TSDB_PATTERN_NOWILDCARDMATCH);
+
+  str = "abcdefgabcdeju";
+  ret = patternMatch("abc%f_", str, 1, &info);
+  EXPECT_EQ(ret, TSDB_PATTERN_NOMATCH);
+
+  str = "abcdefgabcdeju";
+  ret = patternMatch("ab", str, 2, &info);
+  EXPECT_EQ(ret, TSDB_PATTERN_MATCH);
+
+  str = "abcdefgabcdeju";
+  ret = patternMatch("a%", str, 2, &info);
+  EXPECT_EQ(ret, TSDB_PATTERN_MATCH);
+
+  str = "abcdefgabcdeju";
+  ret = patternMatch("a__", str, 2, &info);
+  EXPECT_EQ(ret, TSDB_PATTERN_NOMATCH);
+}
diff --git a/src/query/tests/resultBufferTest.cpp b/src/query/tests/resultBufferTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..fca9ac8f9d82911975dc9e917b48b93be26142de
--- /dev/null
+++ b/src/query/tests/resultBufferTest.cpp
@@ -0,0 +1,35 @@
+#include <gtest/gtest.h>
+#include <cassert>
+#include <iostream>
+
+#include "taos.h"
+#include "qresultBuf.h"
+#include "tsdb.h"
+
+namespace {
+// simple test
+void simpleTest() {
+  SDiskbasedResultBuf* pResultBuf = NULL;
+  int32_t ret = createDiskbasedResultBuffer(&pResultBuf, 1000, 64);
+  
+  int32_t pageId = 0;
+  int32_t groupId = 0;
+  
+  tFilePage* pBufPage = getNewDataBuf(pResultBuf, groupId, &pageId);
+  ASSERT_TRUE(pBufPage != NULL);
+  
+  ASSERT_EQ(getNumOfRowsPerPage(pResultBuf), (16384L - sizeof(int64_t))/64);
+  ASSERT_EQ(getResBufSize(pResultBuf), 1000*16384L);
+  
+  SIDList list = getDataBufPagesIdList(pResultBuf, groupId);
+  ASSERT_EQ(list.size, 1);
+  
+  ASSERT_EQ(getNumOfResultBufGroupId(pResultBuf), 1);
+  
+  destroyResultBuf(pResultBuf);
+}
+} // namespace
+
+TEST(testCase, resultBufferTest) {
+  simpleTest();
+}
diff --git a/src/query/tests/tsBufTest.cpp b/src/query/tests/tsBufTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..2392bd00b53c52126585d5bf1e795fe8db15f106
--- /dev/null
+++ b/src/query/tests/tsBufTest.cpp
@@ -0,0 +1,451 @@
+#include <gtest/gtest.h>
+#include <cassert>
+#include <iostream>
+
+#include "taos.h"
+#include "tsdb.h"
+
+#include "tstoken.h"
+#include "ttime.h"
+#include "tutil.h"
+#include "qtsbuf.h"
+
+namespace {
+/**
+ *
+ * @param num  total number
+ * @param step gap between two consecutive ts
+ * @return
+ */
+int64_t* createTsList(int32_t num, int64_t start, int32_t step) {
+  int64_t* pList = (int64_t*)malloc(num * sizeof(int64_t));
+
+  for (int64_t i = 0; i < num; ++i) {
+    pList[i] = start + i * step;
+  }
+
+  return pList;
+}
+
+// simple test
+void simpleTest() {
+  STSBuf* pTSBuf = tsBufCreate(true);
+
+  // write 10 ts points
+  int32_t num = 10;
+  int64_t tag = 1;
+
+  int64_t* list = createTsList(10, 10000000, 30);
+  tsBufAppend(pTSBuf, 0, tag, (const char*)list, num * sizeof(int64_t));
+  EXPECT_EQ(pTSBuf->tsOrder, TSQL_SO_ASC);
+
+  EXPECT_EQ(pTSBuf->tsData.len, sizeof(int64_t) * num);
+  EXPECT_EQ(pTSBuf->block.tag, tag);
+  EXPECT_EQ(pTSBuf->numOfVnodes, 1);
+
+  tsBufFlush(pTSBuf);
+  EXPECT_EQ(pTSBuf->tsData.len, 0);
+  EXPECT_EQ(pTSBuf->block.numOfElem, num);
+
+  tsBufDestory(pTSBuf);
+}
+
+// one large list of ts, the ts list need to be split into several small blocks
+void largeTSTest() {
+  STSBuf* pTSBuf = tsBufCreate(true);
+
+  // write 10 ts points
+  int32_t num = 1000000;
+  int64_t tag = 1;
+
+  int64_t* list = createTsList(num, 10000000, 30);
+  tsBufAppend(pTSBuf, 0, tag, (const char*)list, num * sizeof(int64_t));
+
+  // the data has been flush to disk, no data in cache
+  EXPECT_EQ(pTSBuf->tsData.len, 0);
+  EXPECT_EQ(pTSBuf->block.tag, tag);
+  EXPECT_EQ(pTSBuf->numOfVnodes, 1);
+  EXPECT_EQ(pTSBuf->tsOrder, TSQL_SO_ASC);
+
+  tsBufFlush(pTSBuf);
+  EXPECT_EQ(pTSBuf->tsData.len, 0);
+  EXPECT_EQ(pTSBuf->block.numOfElem, num);
+
+  tsBufDestory(pTSBuf);
+}
+
+void multiTagsTest() {
+  STSBuf* pTSBuf = tsBufCreate(true);
+
+  int32_t num = 10000;
+  int64_t tag = 1;
+  int64_t start = 10000000;
+  int32_t numOfTags = 50;
+  int32_t step = 30;
+
+  for (int32_t i = 0; i < numOfTags; ++i) {
+    int64_t* list = createTsList(num, start, step);
+    tsBufAppend(pTSBuf, 0, i, (const char*)list, num * sizeof(int64_t));
+    free(list);
+
+    start += step * num;
+  }
+
+  EXPECT_EQ(pTSBuf->tsOrder, TSQL_SO_ASC);
+  EXPECT_EQ(pTSBuf->tsData.len, num * sizeof(int64_t));
+
+  EXPECT_EQ(pTSBuf->block.tag, numOfTags - 1);
+  EXPECT_EQ(pTSBuf->numOfVnodes, 1);
+
+  tsBufFlush(pTSBuf);
+  EXPECT_EQ(pTSBuf->tsData.len, 0);
+  EXPECT_EQ(pTSBuf->block.numOfElem, num);
+
+  tsBufDestory(pTSBuf);
+}
+
+void multiVnodeTagsTest() {
+  STSBuf* pTSBuf = tsBufCreate(true);
+
+  int32_t num = 10000;
+  int64_t start = 10000000;
+  int32_t numOfTags = 50;
+  int32_t step = 30;
+
+  // 2000 vnodes
+  for (int32_t j = 0; j < 20; ++j) {
+    // vnodeId:0
+    start = 10000000;
+    for (int32_t i = 0; i < numOfTags; ++i) {
+      int64_t* list = createTsList(num, start, step);
+      tsBufAppend(pTSBuf, j, i, (const char*)list, num * sizeof(int64_t));
+      free(list);
+
+      start += step * num;
+    }
+
+    EXPECT_EQ(pTSBuf->numOfVnodes, j + 1);
+  }
+
+  EXPECT_EQ(pTSBuf->tsOrder, TSQL_SO_ASC);
+  EXPECT_EQ(pTSBuf->tsData.len, num * sizeof(int64_t));
+  EXPECT_EQ(pTSBuf->block.tag, numOfTags - 1);
+
+  EXPECT_EQ(pTSBuf->tsData.len, num * sizeof(int64_t));
+
+  EXPECT_EQ(pTSBuf->block.tag, numOfTags - 1);
+
+  tsBufFlush(pTSBuf);
+  EXPECT_EQ(pTSBuf->tsData.len, 0);
+  EXPECT_EQ(pTSBuf->block.numOfElem, num);
+
+  tsBufDestory(pTSBuf);
+}
+
+void loadDataTest() {
+  STSBuf* pTSBuf = tsBufCreate(true);
+
+  int32_t num = 10000;
+  int64_t oldStart = 10000000;
+  int32_t numOfTags = 50;
+  int32_t step = 30;
+  int32_t numOfVnode = 200;
+
+  // 10000 vnodes
+  for (int32_t j = 0; j < numOfVnode; ++j) {
+    // vnodeId:0
+    int64_t start = 10000000;
+    for (int32_t i = 0; i < numOfTags; ++i) {
+      int64_t* list = createTsList(num, start, step);
+      tsBufAppend(pTSBuf, j, i, (const char*)list, num * sizeof(int64_t));
+      printf("%d - %lld\n", i, list[0]);
+
+      free(list);
+      start += step * num;
+    }
+
+    EXPECT_EQ(pTSBuf->numOfVnodes, j + 1);
+  }
+
+  EXPECT_EQ(pTSBuf->tsOrder, TSQL_SO_ASC);
+
+  EXPECT_EQ(pTSBuf->tsData.len, num * sizeof(int64_t));
+  EXPECT_EQ(pTSBuf->block.tag, numOfTags - 1);
+
+  EXPECT_EQ(pTSBuf->tsData.len, num * sizeof(int64_t));
+
+  EXPECT_EQ(pTSBuf->block.tag, numOfTags - 1);
+
+  tsBufFlush(pTSBuf);
+  EXPECT_EQ(pTSBuf->tsData.len, 0);
+  EXPECT_EQ(pTSBuf->block.numOfElem, num);
+
+  // create from exists file
+  STSBuf* pNewBuf = tsBufCreateFromFile(pTSBuf->path, false);
+  EXPECT_EQ(pNewBuf->tsOrder, pTSBuf->tsOrder);
+  EXPECT_EQ(pNewBuf->numOfVnodes, numOfVnode);
+  EXPECT_EQ(pNewBuf->fileSize, pTSBuf->fileSize);
+
+  EXPECT_EQ(pNewBuf->pData[0].info.offset, pTSBuf->pData[0].info.offset);
+  EXPECT_EQ(pNewBuf->pData[0].info.numOfBlocks, pTSBuf->pData[0].info.numOfBlocks);
+  EXPECT_EQ(pNewBuf->pData[0].info.compLen, pTSBuf->pData[0].info.compLen);
+
+  EXPECT_STREQ(pNewBuf->path, pTSBuf->path);
+
+  tsBufResetPos(pNewBuf);
+
+  int64_t s = taosGetTimestampUs();
+  printf("start:%lld\n", s);
+
+  int32_t x = 0;
+  while (tsBufNextPos(pNewBuf)) {
+    STSElem elem = tsBufGetElem(pNewBuf);
+    if (++x == 100000000) {
+      break;
+    }
+
+    //    printf("%d-%lld-%lld\n", elem.vnode, elem.tag, elem.ts);
+  }
+
+  int64_t e = taosGetTimestampUs();
+  printf("end:%lld, elapsed:%lld, total obj:%d\n", e, e - s, x);
+}
+
+void randomIncTsTest() {}
+
+void TSTraverse() {
+  // 10000 vnodes
+  int32_t num = 200000;
+  int64_t oldStart = 10000000;
+  int32_t numOfTags = 3;
+  int32_t step = 30;
+  int32_t numOfVnode = 2;
+
+  STSBuf* pTSBuf = tsBufCreate(true);
+
+  for (int32_t j = 0; j < numOfVnode; ++j) {
+    // vnodeId:0
+    int64_t start = 10000000;
+    for (int32_t i = 0; i < numOfTags; ++i) {
+      int64_t* list = createTsList(num, start, step);
+      tsBufAppend(pTSBuf, j, i, (const char*)list, num * sizeof(int64_t));
+      printf("%d - %d - %lld, %lld\n", j, i, list[0], list[num - 1]);
+
+      free(list);
+      start += step * num;
+
+      list = createTsList(num, start, step);
+      tsBufAppend(pTSBuf, j, i, (const char*)list, num * sizeof(int64_t));
+      printf("%d - %d - %lld, %lld\n", j, i, list[0], list[num - 1]);
+      free(list);
+
+      start += step * num;
+    }
+
+    EXPECT_EQ(pTSBuf->numOfVnodes, j + 1);
+  }
+
+  tsBufResetPos(pTSBuf);
+
+  ////////////////////////////////////////////////////////////////////////////////////////
+  // reverse traverse
+  int64_t s = taosGetTimestampUs();
+  printf("start:%lld\n", s);
+
+  pTSBuf->cur.order = TSQL_SO_DESC;
+
+  // complete reverse traverse
+  int32_t x = 0;
+  while (tsBufNextPos(pTSBuf)) {
+    STSElem elem = tsBufGetElem(pTSBuf);
+    //    printf("%d-%lld-%lld\n", elem.vnode, elem.tag, elem.ts);
+  }
+
+  // specify the data block with vnode and tags value
+  tsBufResetPos(pTSBuf);
+  pTSBuf->cur.order = TSQL_SO_DESC;
+
+  int32_t startVnode = 1;
+  int32_t startTag = 2;
+
+  tsBufGetElemStartPos(pTSBuf, startVnode, startTag);
+
+  int32_t totalOutput = 10;
+  while (1) {
+    STSElem elem = tsBufGetElem(pTSBuf);
+    printf("%d-%lld-%lld\n", elem.vnode, elem.tag, elem.ts);
+
+    if (!tsBufNextPos(pTSBuf)) {
+      break;
+    }
+
+    if (--totalOutput <= 0) {
+      totalOutput = 10;
+
+      tsBufGetElemStartPos(pTSBuf, startVnode, --startTag);
+
+      if (startTag == 0) {
+        startVnode -= 1;
+        startTag = 3;
+      }
+
+      if (startVnode < 0) {
+        break;
+      }
+    }
+  }
+
+  /////////////////////////////////////////////////////////////////////////////////
+  // traverse
+  pTSBuf->cur.order = TSQL_SO_ASC;
+  tsBufResetPos(pTSBuf);
+
+  // complete forwards traverse
+  while (tsBufNextPos(pTSBuf)) {
+    STSElem elem = tsBufGetElem(pTSBuf);
+    //    printf("%d-%lld-%lld\n", elem.vnode, elem.tag, elem.ts);
+  }
+
+  // specify the data block with vnode and tags value
+  tsBufResetPos(pTSBuf);
+  pTSBuf->cur.order = TSQL_SO_ASC;
+
+  startVnode = 1;
+  startTag = 2;
+
+  tsBufGetElemStartPos(pTSBuf, startVnode, startTag);
+
+  totalOutput = 10;
+  while (1) {
+    STSElem elem = tsBufGetElem(pTSBuf);
+    printf("%d-%lld-%lld\n", elem.vnode, elem.tag, elem.ts);
+
+    if (!tsBufNextPos(pTSBuf)) {
+      break;
+    }
+
+    if (--totalOutput <= 0) {
+      totalOutput = 10;
+
+      tsBufGetElemStartPos(pTSBuf, startVnode, --startTag);
+
+      if (startTag < 0) {
+        startVnode -= 1;
+        startTag = 3;
+      }
+
+      if (startVnode < 0) {
+        break;
+      }
+    }
+  }
+}
+
+void performanceTest() {}
+
+void emptyTagTest() {}
+
+void invalidFileTest() {
+  const char* cmd = "touch /tmp/test";
+
+  // create empty file
+  system(cmd);
+
+  STSBuf* pNewBuf = tsBufCreateFromFile("/tmp/test", true);
+  EXPECT_TRUE(pNewBuf == NULL);
+
+  pNewBuf = tsBufCreateFromFile("/tmp/911", true);
+  EXPECT_TRUE(pNewBuf == NULL);
+}
+
+void mergeDiffVnodeBufferTest() {
+  STSBuf* pTSBuf1 = tsBufCreate(true);
+  STSBuf* pTSBuf2 = tsBufCreate(true);
+
+  int32_t step = 30;
+  int32_t num = 1000;
+  int32_t numOfTags = 10;
+
+  // vnodeId:0
+  int64_t start = 10000000;
+  for (int32_t i = 0; i < numOfTags; ++i) {
+    int64_t* list = createTsList(num, start, step);
+    tsBufAppend(pTSBuf1, 0, i, (const char*)list, num * sizeof(int64_t));
+    tsBufAppend(pTSBuf2, 0, i, (const char*)list, num * sizeof(int64_t));
+
+    free(list);
+
+    start += step * num;
+  }
+
+  tsBufFlush(pTSBuf2);
+
+  tsBufMerge(pTSBuf1, pTSBuf2, 9);
+  EXPECT_EQ(pTSBuf1->numOfVnodes, 2);
+  EXPECT_EQ(pTSBuf1->numOfTotal, numOfTags * 2 * num);
+
+  tsBufDisplay(pTSBuf1);
+
+  tsBufDestory(pTSBuf2);
+  tsBufDestory(pTSBuf1);
+}
+
+void mergeIdenticalVnodeBufferTest() {
+  STSBuf* pTSBuf1 = tsBufCreate(true);
+  STSBuf* pTSBuf2 = tsBufCreate(true);
+
+  int32_t step = 30;
+  int32_t num = 1000;
+  int32_t numOfTags = 10;
+
+  // vnodeId:0
+  int64_t start = 10000000;
+  for (int32_t i = 0; i < numOfTags; ++i) {
+    int64_t* list = createTsList(num, start, step);
+
+    tsBufAppend(pTSBuf1, 12, i, (const char*)list, num * sizeof(int64_t));
+    free(list);
+
+    start += step * num;
+  }
+
+  for (int32_t i = numOfTags; i < numOfTags * 2; ++i) {
+    int64_t* list = createTsList(num, start, step);
+
+    tsBufAppend(pTSBuf2, 77, i, (const char*)list, num * sizeof(int64_t));
+    free(list);
+
+    start += step * num;
+  }
+
+  tsBufFlush(pTSBuf2);
+
+  tsBufMerge(pTSBuf1, pTSBuf2, 12);
+  EXPECT_EQ(pTSBuf1->numOfVnodes, 1);
+  EXPECT_EQ(pTSBuf1->numOfTotal, numOfTags * 2 * num);
+
+  tsBufResetPos(pTSBuf1);
+  while (tsBufNextPos(pTSBuf1)) {
+    STSElem elem = tsBufGetElem(pTSBuf1);
+    EXPECT_EQ(elem.vnode, 12);
+
+    printf("%d-%lld-%lld\n", elem.vnode, elem.tag, elem.ts);
+  }
+
+  tsBufDestory(pTSBuf1);
+  tsBufDestory(pTSBuf2);
+}
+}  // namespace
+
+TEST(testCase, tsBufTest) {
+  simpleTest();
+  largeTSTest();
+  multiTagsTest();
+  multiVnodeTagsTest();
+  loadDataTest();
+  invalidFileTest();
+  //  randomIncTsTest();
+  TSTraverse();
+  mergeDiffVnodeBufferTest();
+  mergeIdenticalVnodeBufferTest();
+}
diff --git a/src/query/tests/unitTest.cpp b/src/query/tests/unitTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..c7520c90f9fbdb818d85d8f3b321c49820441f2d
--- /dev/null
+++ b/src/query/tests/unitTest.cpp
@@ -0,0 +1,769 @@
+#include <gtest/gtest.h>
+#include <cassert>
+#include <iostream>
+
+#include "taos.h"
+#include "tsdb.h"
+
+#include "../../client/inc/tscUtil.h"
+#include "ttime.h"
+#include "tutil.h"
+#include "tvariant.h"
+#include "ttokendef.h"
+
+namespace {
+int32_t testValidateName(char* name) {
+  SSQLToken token = {0};
+  token.z = name;
+  token.n = strlen(name);
+  token.type = 0;
+
+  tSQLGetToken(name, &token.type);
+  return tscValidateName(&token);
+}
+}
+
+static void _init_tvariant_bool(tVariant* t) {
+  t->i64Key = TSDB_FALSE;
+  t->nType = TSDB_DATA_TYPE_BOOL;
+}
+
+static void _init_tvariant_tinyint(tVariant* t) {
+  t->i64Key = -27;
+  t->nType = TSDB_DATA_TYPE_TINYINT;
+}
+
+static void _init_tvariant_int(tVariant* t) {
+  t->i64Key = -23997659;
+  t->nType = TSDB_DATA_TYPE_INT;
+}
+
+static void _init_tvariant_bigint(tVariant* t) {
+  t->i64Key = -3333333333333;
+  t->nType = TSDB_DATA_TYPE_BIGINT;
+}
+
+static void _init_tvariant_float(tVariant* t) {
+  t->dKey = -8991212199.8987878776;
+  t->nType = TSDB_DATA_TYPE_FLOAT;
+}
+
+static void _init_tvariant_binary(tVariant* t) {
+  tVariantDestroy(t);
+
+  t->pz = (char*)calloc(1, 20);  //"2e3");
+  t->nType = TSDB_DATA_TYPE_BINARY;
+  strcpy(t->pz, "2e5");
+  t->nLen = strlen(t->pz);
+}
+
+static void _init_tvariant_nchar(tVariant* t) {
+  tVariantDestroy(t);
+
+  t->wpz = (wchar_t*)calloc(1, 20 * TSDB_NCHAR_SIZE);
+  t->nType = TSDB_DATA_TYPE_NCHAR;
+  wcscpy(t->wpz, L"-2000000.8765");
+  t->nLen = wcslen(t->wpz);
+}
+
+int main(int argc, char** argv) {
+  testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
+
+/* test validate the names for table/database */
+TEST(testCase, db_table_name) {
+
+  char t01[] = "abc";
+  EXPECT_EQ(testValidateName(t01), TSDB_CODE_SUCCESS);
+
+  char t02[] = "'abc'";
+  EXPECT_EQ(testValidateName(t02), TSDB_CODE_SUCCESS);
+
+  char t1[] = "abc.def";
+  EXPECT_EQ(testValidateName(t1), TSDB_CODE_SUCCESS);
+  printf("%s\n", t1);
+
+  char t2[] = "'abc.def'";
+  EXPECT_EQ(testValidateName(t2), TSDB_CODE_SUCCESS);
+  printf("%s\n", t2);
+
+  char t3[] = "'abc'.def";
+  EXPECT_EQ(testValidateName(t3), TSDB_CODE_SUCCESS);
+  printf("%s\n", t3);
+
+  char t4[] = "'abc'.'def'";
+  EXPECT_EQ(testValidateName(t4), TSDB_CODE_SUCCESS);
+
+  char t5[] = "table.'def'";
+  EXPECT_EQ(testValidateName(t5), TSDB_CODE_INVALID_SQL);
+
+  char t6[] = "'table'.'def'";
+  EXPECT_EQ(testValidateName(t6), TSDB_CODE_INVALID_SQL);
+
+  char t7[] = "'_ab1234'.'def'";
+  EXPECT_EQ(testValidateName(t7), TSDB_CODE_SUCCESS);
+  printf("%s\n", t7);
+
+  char t8[] = "'_ab&^%1234'.'def'";
+  EXPECT_EQ(testValidateName(t8), TSDB_CODE_INVALID_SQL);
+
+  char t9[] = "'_123'.'gtest中文'";
+  EXPECT_EQ(testValidateName(t9), TSDB_CODE_INVALID_SQL);
+
+  char t10[] = "abc.'gtest中文'";
+  EXPECT_EQ(testValidateName(t10), TSDB_CODE_INVALID_SQL);
+
+  char t10_1[] = "abc.'中文gtest'";
+  EXPECT_EQ(testValidateName(t10_1), TSDB_CODE_INVALID_SQL);
+  
+  char t11[] = "'192.168.0.1'.abc";
+  EXPECT_EQ(testValidateName(t11), TSDB_CODE_INVALID_SQL);
+
+  char t12[] = "192.168.0.1.abc";
+  EXPECT_EQ(testValidateName(t12), TSDB_CODE_INVALID_SQL);
+
+  char t13[] = "abc.";
+  EXPECT_EQ(testValidateName(t13), TSDB_CODE_INVALID_SQL);
+
+  char t14[] = ".abc";
+  EXPECT_EQ(testValidateName(t14), TSDB_CODE_INVALID_SQL);
+
+  char t15[] = ".'abc'";
+  EXPECT_EQ(testValidateName(t15), TSDB_CODE_INVALID_SQL);
+
+  char t16[] = ".abc'";
+  EXPECT_EQ(testValidateName(t16), TSDB_CODE_INVALID_SQL);
+
+  char t17[] = "123a.\"abc\"";
+  EXPECT_EQ(testValidateName(t17), TSDB_CODE_INVALID_SQL);
+  printf("%s\n", t17);
+
+  char t18[] = "a.\"abc\"";
+  EXPECT_EQ(testValidateName(t18), TSDB_CODE_SUCCESS);
+  printf("%s\n", t18);
+
+  char t19[] = "'_ab1234'.'def'.'ab123'";
+  EXPECT_EQ(testValidateName(t19), TSDB_CODE_INVALID_SQL);
+
+  char t20[] = "'_ab1234*&^'";
+  EXPECT_EQ(testValidateName(t20), TSDB_CODE_INVALID_SQL);
+
+  char t21[] = "'1234_abc'";
+  EXPECT_EQ(testValidateName(t21), TSDB_CODE_INVALID_SQL);
+
+
+  // =======Containing capital letters=================
+  char t30[] = "ABC";
+  EXPECT_EQ(testValidateName(t30), TSDB_CODE_SUCCESS);
+
+  char t31[] = "'ABC'";
+  EXPECT_EQ(testValidateName(t31), TSDB_CODE_SUCCESS);
+
+  char t32[] = "ABC.def";
+  EXPECT_EQ(testValidateName(t32), TSDB_CODE_SUCCESS);
+
+  char t33[] = "'ABC.def";
+  EXPECT_EQ(testValidateName(t33), TSDB_CODE_INVALID_SQL);
+
+  char t33_0[] = "abc.DEF'";
+  EXPECT_EQ(testValidateName(t33_0), TSDB_CODE_INVALID_SQL);
+  
+  char t34[] = "'ABC.def'";
+  //int32_t tmp0 = testValidateName(t34);
+  EXPECT_EQ(testValidateName(t34), TSDB_CODE_SUCCESS);
+
+  char t35[] = "'ABC'.def";
+  EXPECT_EQ(testValidateName(t35), TSDB_CODE_SUCCESS);
+
+  char t36[] = "'ABC'.'DEF'";
+  EXPECT_EQ(testValidateName(t36), TSDB_CODE_SUCCESS);
+
+  char t37[] = "abc.'DEF'";
+  EXPECT_EQ(testValidateName(t37), TSDB_CODE_SUCCESS);
+
+  char t37_1[] = "abc.'_123DEF'";
+  EXPECT_EQ(testValidateName(t37_1), TSDB_CODE_SUCCESS);
+
+  char t38[] = "'abc'.'DEF'";
+  EXPECT_EQ(testValidateName(t38), TSDB_CODE_SUCCESS);
+
+  // do not use key words 
+  char t39[] = "table.'DEF'";
+  EXPECT_EQ(testValidateName(t39), TSDB_CODE_INVALID_SQL);
+
+  char t40[] = "'table'.'DEF'";
+  EXPECT_EQ(testValidateName(t40), TSDB_CODE_INVALID_SQL);
+
+  char t41[] = "'_abXYZ1234'.'deFF'";
+  EXPECT_EQ(testValidateName(t41), TSDB_CODE_SUCCESS);
+
+  char t42[] = "'_abDEF&^%1234'.'DIef'";
+  EXPECT_EQ(testValidateName(t42), TSDB_CODE_INVALID_SQL);
+
+  char t43[] = "'_123'.'Gtest中文'";
+  EXPECT_EQ(testValidateName(t43), TSDB_CODE_INVALID_SQL);
+
+  char t44[] = "'aABC'.'Gtest中文'";
+  EXPECT_EQ(testValidateName(t44), TSDB_CODE_INVALID_SQL);
+  
+  char t45[] = "'ABC'.";
+  EXPECT_EQ(testValidateName(t45), TSDB_CODE_INVALID_SQL);
+
+  char t46[] = ".'ABC'";
+  EXPECT_EQ(testValidateName(t46), TSDB_CODE_INVALID_SQL);
+
+  char t47[] = "a.\"aTWc\"";
+  EXPECT_EQ(testValidateName(t47), TSDB_CODE_SUCCESS);
+
+ // ================has space =================
+  char t60[] = " ABC ";
+  EXPECT_EQ(testValidateName(t60), TSDB_CODE_INVALID_SQL);
+
+  char t60_1[] = "   ABC ";
+  EXPECT_EQ(testValidateName(t60_1), TSDB_CODE_INVALID_SQL);
+
+  char t61[] = "' ABC '";
+  EXPECT_EQ(testValidateName(t61), TSDB_CODE_SUCCESS);
+
+  char t61_1[] = "'  ABC '";
+  EXPECT_EQ(testValidateName(t61_1), TSDB_CODE_SUCCESS);
+
+  char t62[] = " ABC . def ";
+  EXPECT_EQ(testValidateName(t62), TSDB_CODE_INVALID_SQL);
+
+  char t63[] = "' ABC . def ";
+  EXPECT_EQ(testValidateName(t63), TSDB_CODE_INVALID_SQL);
+
+  char t63_0[] = "  abc . DEF ' ";
+  EXPECT_EQ(testValidateName(t63_0), TSDB_CODE_INVALID_SQL);
+  
+  char t64[] = " '  ABC .  def ' ";
+  //int32_t tmp1 = testValidateName(t64);
+  EXPECT_EQ(testValidateName(t64), TSDB_CODE_INVALID_SQL);
+
+  char t65[] = " ' ABC  '. def ";
+  EXPECT_EQ(testValidateName(t65), TSDB_CODE_INVALID_SQL);
+
+  char t66[] = "' ABC '.'  DEF '";
+  EXPECT_EQ(testValidateName(t66), TSDB_CODE_SUCCESS);
+
+  char t67[] = "abc . '  DEF  '";
+  EXPECT_EQ(testValidateName(t67), TSDB_CODE_INVALID_SQL);
+
+  char t68[] = "'  abc '.'   DEF '";
+  EXPECT_EQ(testValidateName(t68), TSDB_CODE_SUCCESS);
+
+  // do not use key words 
+  char t69[] = "table.'DEF'";
+  EXPECT_EQ(testValidateName(t69), TSDB_CODE_INVALID_SQL);
+
+  char t70[] = "'table'.'DEF'";
+  EXPECT_EQ(testValidateName(t70), TSDB_CODE_INVALID_SQL);
+
+  char t71[] = "'_abXYZ1234  '.' deFF  '";
+  EXPECT_EQ(testValidateName(t71), TSDB_CODE_SUCCESS);
+
+  char t72[] = "'_abDEF&^%1234'.'  DIef'";
+  EXPECT_EQ(testValidateName(t72), TSDB_CODE_INVALID_SQL);
+
+  char t73[] = "'_123'.'  Gtest中文'";
+  EXPECT_EQ(testValidateName(t73), TSDB_CODE_INVALID_SQL);
+
+  char t74[] = "' aABC'.'Gtest中文'";
+  EXPECT_EQ(testValidateName(t74), TSDB_CODE_INVALID_SQL);
+  
+  char t75[] = "' ABC '.";
+  EXPECT_EQ(testValidateName(t75), TSDB_CODE_INVALID_SQL);
+
+  char t76[] = ".' ABC'";
+  EXPECT_EQ(testValidateName(t76), TSDB_CODE_INVALID_SQL);
+
+  char t77[] = " a . \"aTWc\" ";
+  EXPECT_EQ(testValidateName(t77), TSDB_CODE_INVALID_SQL);
+
+  char t78[] = "  a.\"aTWc  \"";
+  EXPECT_EQ(testValidateName(t78), TSDB_CODE_INVALID_SQL);
+
+
+  // ===============muti string by space ===================
+  // There's no such case.
+  //char t160[] = "A BC";
+  //EXPECT_EQ(testValidateName(t160), TSDB_CODE_INVALID_SQL);
+  //printf("end:%s\n", t160);
+
+  // There's no such case.
+  //char t161[] = "' A BC '";
+  //EXPECT_EQ(testValidateName(t161), TSDB_CODE_INVALID_SQL);
+
+  char t162[] = " AB C . de f ";
+  EXPECT_EQ(testValidateName(t162), TSDB_CODE_INVALID_SQL);
+
+  char t163[] = "' AB C . de f ";
+  EXPECT_EQ(testValidateName(t163), TSDB_CODE_INVALID_SQL);
+
+  char t163_0[] = "  ab c . DE F ' ";
+  EXPECT_EQ(testValidateName(t163_0), TSDB_CODE_INVALID_SQL);
+  
+  char t164[] = " '  AB C .  de f ' ";
+  //int32_t tmp2 = testValidateName(t164);
+  EXPECT_EQ(testValidateName(t164), TSDB_CODE_INVALID_SQL);
+
+  char t165[] = " ' A BC  '. de f ";
+  EXPECT_EQ(testValidateName(t165), TSDB_CODE_INVALID_SQL);
+
+  char t166[] = "' AB C '.'  DE  F '";
+  EXPECT_EQ(testValidateName(t166), TSDB_CODE_INVALID_SQL);
+
+  char t167[] = "ab  c . '  D  EF  '";
+  EXPECT_EQ(testValidateName(t167), TSDB_CODE_INVALID_SQL);
+
+  char t168[] = "'  a bc '.'   DE  F '";
+  EXPECT_EQ(testValidateName(t168), TSDB_CODE_INVALID_SQL);
+  
+}
+
+/* test parse time function */
+TEST(testCase, parse_time) {
+  taos_options(TSDB_OPTION_TIMEZONE, "GMT-8");
+  char t1[] = "2018-1-1 1:1:1.952798";
+  char t13[] = "1970-1-1 0:0:0";
+
+  int64_t time = 0, time1 = 0;
+
+  taosParseTime(t1, &time, strlen(t1), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, 1514739661952);
+
+  taosParseTime(t13, &time, strlen(t13), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, timezone * MILLISECOND_PER_SECOND);
+
+  char t2[] = "2018-1-1T1:1:1.952Z";
+  taosParseTime(t2, &time, strlen(t2), TSDB_TIME_PRECISION_MILLI);
+
+  EXPECT_EQ(time, 1514739661952 + 28800000);
+
+  char t3[] = "2018-1-1 1:01:01.952";
+  taosParseTime(t3, &time, strlen(t3), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, 1514739661952);
+
+  char t4[] = "2018-1-1 1:01:01.9";
+  char t5[] = "2018-1-1 1:01:1.900";
+  char t6[] = "2018-01-01 1:1:1.90";
+  char t7[] = "2018-01-01 01:01:01.9";
+  char t8[] = "2018-01-01 01:01:01.9007865";
+
+  taosParseTime(t4, &time, strlen(t4), TSDB_TIME_PRECISION_MILLI);
+  taosParseTime(t5, &time1, strlen(t5), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, time1);
+
+  taosParseTime(t4, &time, strlen(t4), TSDB_TIME_PRECISION_MILLI);
+  taosParseTime(t6, &time1, strlen(t6), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, time1);
+
+  taosParseTime(t4, &time, strlen(t4), TSDB_TIME_PRECISION_MILLI);
+  taosParseTime(t7, &time1, strlen(t7), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, time1);
+
+  taosParseTime(t5, &time, strlen(t5), TSDB_TIME_PRECISION_MILLI);
+  taosParseTime(t8, &time1, strlen(t8), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, time1);
+
+  char t9[] = "2017-4-3 1:1:2.980";
+  char t10[] = "2017-4-3T2:1:2.98+9:00";
+  taosParseTime(t9, &time, strlen(t9), TSDB_TIME_PRECISION_MILLI);
+  taosParseTime(t10, &time1, strlen(t10), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, time1);
+
+  char t11[] = "2017-4-3T2:1:2.98+09:00";
+  taosParseTime(t11, &time, strlen(t11), TSDB_TIME_PRECISION_MILLI);
+  taosParseTime(t10, &time1, strlen(t10), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, time1);
+
+  char t12[] = "2017-4-3T2:1:2.98+0900";
+  taosParseTime(t11, &time, strlen(t11), TSDB_TIME_PRECISION_MILLI);
+  taosParseTime(t12, &time1, strlen(t12), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, time1);
+
+  taos_options(TSDB_OPTION_TIMEZONE, "UTC");
+  taosParseTime(t13, &time, strlen(t13), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, 0);
+
+  taos_options(TSDB_OPTION_TIMEZONE, "Asia/Shanghai");
+  char t14[] = "1970-1-1T0:0:0Z";
+  taosParseTime(t14, &time, strlen(t14), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, 0);
+
+  char t40[] = "1970-1-1 0:0:0.999999999";
+  taosParseTime(t40, &time, strlen(t40), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, 999 + timezone * MILLISECOND_PER_SECOND);
+
+  char t41[] = "1997-1-1 0:0:0.999999999";
+  taosParseTime(t41, &time, strlen(t41), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, 852048000999);
+
+  int64_t k = timezone;
+  char    t42[] = "1997-1-1T0:0:0.999999999Z";
+  taosParseTime(t42, &time, strlen(t42), TSDB_TIME_PRECISION_MILLI);
+  EXPECT_EQ(time, 852048000999 - timezone * MILLISECOND_PER_SECOND);
+
+  ////////////////////////////////////////////////////////////////////
+  // illegal timestamp format
+  char t15[] = "2017-12-33 0:0:0";
+  EXPECT_EQ(taosParseTime(t15, &time, strlen(t15), TSDB_TIME_PRECISION_MILLI), -1);
+
+  char t16[] = "2017-12-31 99:0:0";
+  EXPECT_EQ(taosParseTime(t16, &time, strlen(t16), TSDB_TIME_PRECISION_MILLI), -1);
+
+  char t17[] = "2017-12-31T9:0:0";
+  EXPECT_EQ(taosParseTime(t17, &time, strlen(t17), TSDB_TIME_PRECISION_MILLI), -1);
+
+  char t18[] = "2017-12-31T9:0:0.Z";
+  EXPECT_EQ(taosParseTime(t18, &time, strlen(t18), TSDB_TIME_PRECISION_MILLI), -1);
+
+  char t19[] = "2017-12-31 9:0:0.-1";
+  EXPECT_EQ(taosParseTime(t19, &time, strlen(t19), TSDB_TIME_PRECISION_MILLI), -1);
+
+  char t20[] = "2017-12-31 9:0:0.1+12:99";
+  EXPECT_EQ(taosParseTime(t20, &time, strlen(t20), TSDB_TIME_PRECISION_MILLI), 0);
+  EXPECT_EQ(time, 1514682000100);
+
+  char t21[] = "2017-12-31T9:0:0.1+12:99";
+  EXPECT_EQ(taosParseTime(t21, &time, strlen(t21), TSDB_TIME_PRECISION_MILLI), -1);
+
+  char t22[] = "2017-12-31 9:0:0.1+13:1";
+  EXPECT_EQ(taosParseTime(t22, &time, strlen(t22), TSDB_TIME_PRECISION_MILLI), 0);
+
+  char t23[] = "2017-12-31T9:0:0.1+13:1";
+  EXPECT_EQ(taosParseTime(t23, &time, strlen(t23), TSDB_TIME_PRECISION_MILLI), 0);
+}
+
+TEST(testCase, tvariant_convert) {
+  // 1. bool data to all other data types
+  tVariant t = {0};
+  _init_tvariant_bool(&t);
+
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BOOL), 0);
+  EXPECT_EQ(t.i64Key, 0);
+
+  _init_tvariant_bool(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_TINYINT), 0);
+  EXPECT_EQ(t.i64Key, 0);
+
+  _init_tvariant_bool(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_SMALLINT), 0);
+  EXPECT_EQ(t.i64Key, 0);
+
+  _init_tvariant_bool(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BIGINT), 0);
+  EXPECT_EQ(t.i64Key, 0);
+
+  _init_tvariant_bool(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_FLOAT), 0);
+  EXPECT_EQ(t.dKey, 0);
+
+  _init_tvariant_bool(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_DOUBLE), 0);
+  EXPECT_EQ(t.dKey, 0);
+
+  _init_tvariant_bool(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BINARY), 0);
+  EXPECT_STREQ(t.pz, "FALSE");
+  tVariantDestroy(&t);
+
+  _init_tvariant_bool(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_NCHAR), 0);
+  EXPECT_STREQ(t.wpz, L"FALSE");
+  tVariantDestroy(&t);
+
+  // 2. tinyint to other data types
+  _init_tvariant_tinyint(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BOOL), 0);
+  EXPECT_EQ(t.i64Key, 1);
+
+  _init_tvariant_tinyint(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_TINYINT), 0);
+  EXPECT_EQ(t.i64Key, -27);
+
+  _init_tvariant_tinyint(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_SMALLINT), 0);
+  EXPECT_EQ(t.i64Key, -27);
+
+  _init_tvariant_tinyint(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_INT), 0);
+  EXPECT_EQ(t.i64Key, -27);
+
+  _init_tvariant_tinyint(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BIGINT), 0);
+  EXPECT_EQ(t.i64Key, -27);
+
+  _init_tvariant_tinyint(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_FLOAT), 0);
+  EXPECT_EQ(t.dKey, -27);
+
+  _init_tvariant_tinyint(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_DOUBLE), 0);
+  EXPECT_EQ(t.dKey, -27);
+
+  _init_tvariant_tinyint(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BINARY), 0);
+  EXPECT_STREQ(t.pz, "-27");
+  tVariantDestroy(&t);
+
+  _init_tvariant_tinyint(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_NCHAR), 0);
+  EXPECT_STREQ(t.wpz, L"-27");
+  tVariantDestroy(&t);
+
+  // 3. int to other data
+  // types//////////////////////////////////////////////////////////////////
+  _init_tvariant_int(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BOOL), 0);
+  EXPECT_EQ(t.i64Key, 1);
+
+  _init_tvariant_int(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_TINYINT), 0);
+
+  _init_tvariant_int(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_SMALLINT), 0);
+
+  _init_tvariant_int(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_INT), 0);
+  EXPECT_EQ(t.i64Key, -23997659);
+
+  _init_tvariant_int(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BIGINT), 0);
+  EXPECT_EQ(t.i64Key, -23997659);
+
+  _init_tvariant_int(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_FLOAT), 0);
+  EXPECT_EQ(t.dKey, -23997659);
+
+  _init_tvariant_int(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_DOUBLE), 0);
+  EXPECT_EQ(t.dKey, -23997659);
+
+  _init_tvariant_int(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BINARY), 0);
+  EXPECT_STREQ(t.pz, "-23997659");
+  tVariantDestroy(&t);
+
+  _init_tvariant_int(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_NCHAR), 0);
+  EXPECT_STREQ(t.wpz, L"-23997659");
+  tVariantDestroy(&t);
+
+  // 4. bigint to other data
+  // type//////////////////////////////////////////////////////////////////////////////
+  _init_tvariant_bigint(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BOOL), 0);
+  EXPECT_EQ(t.i64Key, 1);
+
+  _init_tvariant_bigint(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_TINYINT), 0);
+
+  _init_tvariant_bigint(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_SMALLINT), 0);
+
+  _init_tvariant_bigint(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_INT), 0);
+
+  _init_tvariant_bigint(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BIGINT), 0);
+  EXPECT_EQ(t.i64Key, -3333333333333);
+
+  _init_tvariant_bigint(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_FLOAT), 0);
+  EXPECT_EQ(t.dKey, -3333333333333);
+
+  _init_tvariant_bigint(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_DOUBLE), 0);
+  EXPECT_EQ(t.dKey, -3333333333333);
+
+  _init_tvariant_bigint(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BINARY), 0);
+  EXPECT_STREQ(t.pz, "-3333333333333");
+  tVariantDestroy(&t);
+
+  _init_tvariant_bigint(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_NCHAR), 0);
+  EXPECT_STREQ(t.wpz, L"-3333333333333");
+  tVariantDestroy(&t);
+
+  // 5. float to other data
+  // types////////////////////////////////////////////////////////////////////////
+  _init_tvariant_float(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BOOL), 0);
+  EXPECT_EQ(t.i64Key, 1);
+
+  _init_tvariant_float(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BIGINT), 0);
+  EXPECT_EQ(t.i64Key, -8991212199);
+
+  _init_tvariant_float(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_FLOAT), 0);
+  EXPECT_DOUBLE_EQ(t.dKey, -8991212199.8987885);
+
+  _init_tvariant_float(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_DOUBLE), 0);
+  EXPECT_DOUBLE_EQ(t.dKey, -8991212199.8987885);
+
+  _init_tvariant_float(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BINARY), 0);
+  EXPECT_STREQ(t.pz, "-8991212199.898788");
+  tVariantDestroy(&t);
+
+  _init_tvariant_float(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_NCHAR), 0);
+  EXPECT_STREQ(t.wpz, L"-8991212199.898788");
+  tVariantDestroy(&t);
+
+  // 6. binary to other data types
+  // //////////////////////////////////////////////////////////////////
+  t.pz = "true";
+  t.nLen = strlen(t.pz);
+  t.nType = TSDB_DATA_TYPE_BINARY;
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BOOL), 0);
+  EXPECT_EQ(t.i64Key, 1);
+
+  _init_tvariant_binary(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BOOL), -1);
+
+  _init_tvariant_binary(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BIGINT), 0);
+  EXPECT_EQ(t.i64Key, 200000);
+
+  _init_tvariant_binary(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_FLOAT), 0);
+  EXPECT_DOUBLE_EQ(t.dKey, 200000);
+
+  _init_tvariant_binary(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_DOUBLE), 0);
+  EXPECT_DOUBLE_EQ(t.dKey, 200000);
+
+  _init_tvariant_binary(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BINARY), 0);
+  EXPECT_STREQ(t.pz, "2e5");
+  tVariantDestroy(&t);
+
+  _init_tvariant_binary(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_NCHAR), 0);
+  EXPECT_STREQ(t.wpz, L"2e5");
+  tVariantDestroy(&t);
+
+  // 7. nchar to other data types
+  // //////////////////////////////////////////////////////////////////
+  t.wpz = L"FALSE";
+  t.nLen = wcslen(t.wpz);
+  t.nType = TSDB_DATA_TYPE_NCHAR;
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BOOL), 0);
+  EXPECT_EQ(t.i64Key, 0);
+
+  _init_tvariant_nchar(&t);
+  EXPECT_LE(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BOOL), 0);
+
+  _init_tvariant_nchar(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BIGINT), 0);
+  EXPECT_EQ(t.i64Key, -2000000);
+
+  _init_tvariant_nchar(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_FLOAT), 0);
+  EXPECT_DOUBLE_EQ(t.dKey, -2000000.8765);
+
+  _init_tvariant_nchar(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_DOUBLE), 0);
+  EXPECT_DOUBLE_EQ(t.dKey, -2000000.8765);
+
+  _init_tvariant_nchar(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_BINARY), 0);
+  EXPECT_STREQ(t.pz, "-2000000.8765");
+  tVariantDestroy(&t);
+
+  _init_tvariant_nchar(&t);
+  EXPECT_EQ(tVariantTypeSetType(&t, TSDB_DATA_TYPE_NCHAR), 0);
+  EXPECT_STREQ(t.wpz, L"-2000000.8765");
+  tVariantDestroy(&t);
+}
+
+TEST(testCase, tGetToken_Test) {
+  char* s = ".123 ";
+  uint32_t type = 0;
+
+  int32_t len = tSQLGetToken(s, &type);
+  EXPECT_EQ(type, TK_FLOAT);
+  EXPECT_EQ(len, strlen(s) - 1);
+
+  char s1[] = "1.123e10 ";
+  len = tSQLGetToken(s1, &type);
+  EXPECT_EQ(type, TK_FLOAT);
+  EXPECT_EQ(len, strlen(s1) - 1);
+
+  char s4[] = "0xff ";
+  len = tSQLGetToken(s4, &type);
+  EXPECT_EQ(type, TK_HEX);
+  EXPECT_EQ(len, strlen(s4) - 1);
+
+  // invalid data type
+  char s2[] = "e10 ";
+  len = tSQLGetToken(s2, &type);
+  EXPECT_FALSE(type == TK_FLOAT);
+
+  char s3[] = "1.1.1.1";
+  len = tSQLGetToken(s3, &type);
+  EXPECT_EQ(type, TK_IPTOKEN);
+  EXPECT_EQ(len, strlen(s3));
+
+  char s5[] = "0x ";
+  len = tSQLGetToken(s5, &type);
+  EXPECT_FALSE(type == TK_HEX);
+}
+
+static SSQLToken createStrToken(char* s) {
+  SSQLToken t = {0};//.type = TK_STRING, .z = s, .n = strlen(s)};
+  t.type = TK_STRING;
+  t.z = s;
+  t.n = strlen(s);
+
+  return t;
+}
+
+TEST(testCase, isValidNumber_test) {
+  SSQLToken t1 = createStrToken("123abc");
+
+  EXPECT_EQ(isValidNumber(&t1), TK_ILLEGAL);
+
+  t1 = createStrToken("0xabc");
+  EXPECT_EQ(isValidNumber(&t1), TK_HEX);
+
+  t1 = createStrToken("0b11101");
+  EXPECT_EQ(isValidNumber(&t1), TK_BIN);
+
+  t1 = createStrToken(".134abc");
+  EXPECT_EQ(isValidNumber(&t1), TK_ILLEGAL);
+
+  t1 = createStrToken("1e1 ");
+  EXPECT_EQ(isValidNumber(&t1), TK_ILLEGAL);
+
+  t1 = createStrToken("1+2");
+  EXPECT_EQ(isValidNumber(&t1), TK_ILLEGAL);
+
+  t1 = createStrToken("-0x123");
+  EXPECT_EQ(isValidNumber(&t1), TK_HEX);
+
+  t1 = createStrToken("-1");
+  EXPECT_EQ(isValidNumber(&t1), TK_INTEGER);
+
+  t1 = createStrToken("-0b1110");
+  EXPECT_EQ(isValidNumber(&t1), TK_BIN);
+
+  t1 = createStrToken("-.234");
+  EXPECT_EQ(isValidNumber(&t1), TK_FLOAT);
+}
+
+TEST(testCase, getTempFilePath_test) {
+  char path[4096] = {0};
+  memset(path, 1, 4096);
+
+  getTmpfilePath("new_tmp", path);
+  printf("%s\n", path);
+}
+
diff --git a/src/util/CMakeLists.txt b/src/util/CMakeLists.txt
index 67ecf39f1b2a0564e8f2bcdc0cb39360652a3965..0844146bd4667a58666f4807c98ce8a19884a4bd 100644
--- a/src/util/CMakeLists.txt
+++ b/src/util/CMakeLists.txt
@@ -29,6 +29,8 @@ IF ((TD_LINUX_64) OR (TD_LINUX_32 AND TD_ARM))
       MESSAGE(STATUS "Failed to find iconv, use default encoding method")
     ENDIF ()
   ENDIF ()
+
+  ADD_SUBDIRECTORY(tests)
 ELSEIF (TD_WINDOWS_64)
   ADD_DEFINITIONS(-DUSE_LIBICONV)
   INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/deps/pthread)
@@ -113,4 +115,3 @@ ENDIF()
 #ENDIF ()
 
 
-
diff --git a/src/util/tests/CMakeLists.txt b/src/util/tests/CMakeLists.txt
new file mode 100644
index 0000000000000000000000000000000000000000..042c925165985a285670f5df845708f92146b353
--- /dev/null
+++ b/src/util/tests/CMakeLists.txt
@@ -0,0 +1,15 @@
+CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
+PROJECT(TDengine)
+
+FIND_PATH(HEADER_GTEST_INCLUDE_DIR gtest.h /usr/include/gtest /usr/local/include/gtest)
+FIND_LIBRARY(LIB_GTEST_STATIC_DIR libgtest.a /usr/lib/ /usr/local/lib)
+
+IF (HEADER_GTEST_INCLUDE_DIR AND LIB_GTEST_STATIC_DIR)
+    MESSAGE(STATUS "gTest library found, build unit test")
+
+    INCLUDE_DIRECTORIES(${HEADER_GTEST_INCLUDE_DIR})
+    AUX_SOURCE_DIRECTORY(${CMAKE_CURRENT_SOURCE_DIR} SOURCE_LIST)
+
+    ADD_EXECUTABLE(utilTest ${SOURCE_LIST})
+    TARGET_LINK_LIBRARIES(utilTest tutil gtest pthread)
+ENDIF()
\ No newline at end of file
diff --git a/src/util/tests/cacheTest.cpp b/src/util/tests/cacheTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..411c899cc010e3f3ca3c39e1d0ff2c06c1c5e873
--- /dev/null
+++ b/src/util/tests/cacheTest.cpp
@@ -0,0 +1,142 @@
+#include <iostream>
+#include <gtest/gtest.h>
+#include <sys/time.h>
+
+#include "taos.h"
+//#include "tsdb.h"
+
+//#include "testCommon.h"
+#include "tstoken.h"
+#include "tutil.h"
+#include "tcache.h"
+#include "ttimer.h"
+#include "ttime.h"
+
+namespace {
+int32_t tsMaxMgmtConnections = 10000;
+int32_t tsMaxMeterConnections = 200;
+}
+// test cache
+TEST(testCase, client_cache_test) {
+  const int32_t REFRESH_TIME_IN_SEC = 2;
+  void* tscTmr = taosTmrInit (tsMaxMgmtConnections*2, 200, 6000, "TSC");
+  SCacheObj* tscCacheHandle = taosCacheInit(tscTmr, REFRESH_TIME_IN_SEC);
+
+  char* key1 = "test1";
+  char* data1 = "test11";
+
+  char* cachedObj = (char*) taosCachePut(tscCacheHandle, key1, data1, strlen(data1), 1);
+  sleep(REFRESH_TIME_IN_SEC+1);
+
+  printf("obj is still valid: %s\n", cachedObj);
+
+  char* data2 = "test22";
+  taosCacheRelease(tscCacheHandle, (void**) &cachedObj, false);
+
+  /* the object is cleared by cache clean operation */
+  cachedObj = (char*) taosCachePut(tscCacheHandle, key1, data2, strlen(data2), 20);
+  printf("after updated: %s\n", cachedObj);
+
+  printf("start to remove data from cache\n");
+  taosCacheRelease(tscCacheHandle, (void**) &cachedObj, false);
+  printf("end of removing data from cache\n");
+
+  getchar();
+
+  char* key3 = "test2";
+  char* data3 = "kkkkkkk";
+
+  char* cachedObj2 = (char*) taosCachePut(tscCacheHandle, key3, data3, strlen(data3), 1);
+  printf("%s\n", cachedObj2);
+
+  taosCacheRelease(tscCacheHandle, (void**) &cachedObj2, false);
+
+  sleep(3);
+  char* d = (char*) taosCacheAcquireByName(tscCacheHandle, key3);
+//    assert(d == NULL);
+
+  char* key5 = "test5";
+  char* data5 = "data5kkkkk";
+  cachedObj2 = (char*) taosCachePut(tscCacheHandle, key5, data5, strlen(data5), 20);
+
+  char* data6= "new Data after updated";
+  taosCacheRelease(tscCacheHandle, (void**) &cachedObj2, false);
+
+  cachedObj2 = (char*) taosCachePut(tscCacheHandle, key5, data6, strlen(data6), 20);
+  printf("%s\n", cachedObj2);
+
+  taosCacheRelease(tscCacheHandle, (void**) &cachedObj2, true);
+
+  char* data7 = "add call update procedure";
+  cachedObj2 = (char*) taosCachePut(tscCacheHandle, key5, data7, strlen(data7), 20);
+  printf("%s\n=======================================\n\n", cachedObj2);
+
+  char* cc = (char*) taosCacheAcquireByName(tscCacheHandle, key5);
+
+  taosCacheRelease(tscCacheHandle, (void**) &cachedObj2, true);
+  taosCacheRelease(tscCacheHandle, (void**) &cc, false);
+
+  char* data8 = "ttft";
+  char* key6 = "key6";
+
+  char* ft = (char*) taosCachePut(tscCacheHandle, key6, data8, strlen(data8), 20);
+  taosCacheRelease(tscCacheHandle, (void**) &ft, false);
+
+  /**
+   * 140ns
+   */
+  uint64_t startTime = taosGetTimestampUs();
+  printf("Cache Performance Test\nstart time:%lld\n", startTime);
+  for(int32_t i=0; i<1000; ++i) {
+    char* dd = (char*) taosCacheAcquireByName(tscCacheHandle, key6);
+    if (dd != NULL) {
+//      printf("get the data\n");
+    } else {
+      printf("data has been released\n");
+    }
+
+    taosCacheRelease(tscCacheHandle, (void**) &dd, false);
+  }
+
+  uint64_t endTime = taosGetTimestampUs();
+  int64_t el = endTime - startTime;
+
+  printf("End of Test, %lld\nTotal Elapsed Time:%lld us.avg:%f us\n", endTime, el, el/1000.0);
+
+  taosCacheCleanup(tscCacheHandle);
+}
+
+TEST(testCase, cache_resize_test) {
+  const int32_t REFRESH_TIME_IN_SEC = 2;
+  void* tscTmr = taosTmrInit (1000*2, 200, 6000, "TSC");
+
+  auto* pCache = taosCacheInit(tscTmr, REFRESH_TIME_IN_SEC);
+
+  char key[256] = {0};
+  char data[1024] = "abcdefghijk";
+  int32_t len = strlen(data);
+
+  uint64_t startTime = taosGetTimestampUs();
+  int32_t num = 10000;
+
+  for(int32_t i = 0; i < num; ++i) {
+    int32_t len = sprintf(key, "abc_%7d", i);
+    taosCachePut(pCache, key, data, len, 3600);
+  }
+  uint64_t endTime = taosGetTimestampUs();
+
+  printf("add 10,000,000 object cost:%lld us, avg:%f us\n", endTime - startTime, (endTime-startTime)/(double)num);
+
+  startTime = taosGetTimestampUs();
+  for(int32_t i = 0; i < num; ++i) {
+    int32_t len = sprintf(key, "abc_%7d", i);
+    void* k = taosCacheAcquireByName(pCache, key);
+    assert(k != 0);
+  }
+  endTime = taosGetTimestampUs();
+  printf("retrieve 10,000,000 object cost:%lld us,avg:%f\n", endTime - startTime, (endTime - startTime)/(double)num);
+
+  taosCacheCleanup(pCache);
+  taosMsleep(20000);
+  getchar();
+}
\ No newline at end of file
diff --git a/src/util/tests/hashTest.cpp b/src/util/tests/hashTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..93a19897416aa2bb3e19d1c5e3d3c28da64d8bb6
--- /dev/null
+++ b/src/util/tests/hashTest.cpp
@@ -0,0 +1,156 @@
+#include <gtest/gtest.h>
+#include <limits.h>
+#include <taosdef.h>
+#include <iostream>
+
+#include "hash.h"
+#include "taos.h"
+#include "ttime.h"
+
+namespace {
+// the simple test code for basic operations
+void simpleTest() {
+  auto* hashTable = (SHashObj*) taosHashInit(64, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), false);
+  ASSERT_EQ(taosHashGetSize(hashTable), 0);
+  
+  // put 400 elements in the hash table
+  for(int32_t i = -200; i < 200; ++i) {
+    taosHashPut(hashTable, (const char*) &i, sizeof(int32_t), (char*) &i, sizeof(int32_t));
+  }
+  
+  ASSERT_EQ(taosHashGetSize(hashTable), 400);
+  
+  for(int32_t i = 0; i < 200; ++i) {
+    char* p = (char*) taosHashGet(hashTable, (const char*) &i, sizeof(int32_t));
+    ASSERT_TRUE(p != nullptr);
+    ASSERT_EQ(*reinterpret_cast<int32_t*>(p), i);
+  }
+  
+  for(int32_t i = 1000; i < 2000; ++i) {
+    taosHashRemove(hashTable, (const char*) &i, sizeof(int32_t));
+  }
+  
+  ASSERT_EQ(taosHashGetSize(hashTable), 400);
+  
+  for(int32_t i = 0; i < 100; ++i) {
+    taosHashRemove(hashTable, (const char*) &i, sizeof(int32_t));
+  }
+  
+  ASSERT_EQ(taosHashGetSize(hashTable), 300);
+  
+  for(int32_t i = 100; i < 150; ++i) {
+    taosHashRemove(hashTable, (const char*) &i, sizeof(int32_t));
+  }
+  
+  ASSERT_EQ(taosHashGetSize(hashTable), 250);
+  taosHashCleanup(hashTable);
+}
+
+void stringKeyTest() {
+  auto* hashTable = (SHashObj*) taosHashInit(64, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BINARY), false);
+  ASSERT_EQ(taosHashGetSize(hashTable), 0);
+  
+  char key[128] = {0};
+  
+  // put 200 elements in the hash table
+  for(int32_t i = 0; i < 1000; ++i) {
+    int32_t len = sprintf(key, "%d_1_%dabcefg_", i, i + 10);
+    taosHashPut(hashTable, key, len, (char*) &i, sizeof(int32_t));
+  }
+  
+  ASSERT_EQ(taosHashGetSize(hashTable), 1000);
+  
+  for(int32_t i = 0; i < 1000; ++i) {
+    int32_t len = sprintf(key, "%d_1_%dabcefg_", i, i + 10);
+    
+    char* p = (char*) taosHashGet(hashTable, key, len);
+    ASSERT_TRUE(p != nullptr);
+    
+    ASSERT_EQ(*reinterpret_cast<int32_t*>(p), i);
+  }
+  
+  for(int32_t i = 500; i < 1000; ++i) {
+    int32_t len = sprintf(key, "%d_1_%dabcefg_", i, i + 10);
+    
+    taosHashRemove(hashTable, key, len);
+  }
+  
+  ASSERT_EQ(taosHashGetSize(hashTable), 500);
+  
+  for(int32_t i = 0; i < 499; ++i) {
+    int32_t len = sprintf(key, "%d_1_%dabcefg_", i, i + 10);
+  
+    taosHashRemove(hashTable, key, len);
+  }
+  
+  ASSERT_EQ(taosHashGetSize(hashTable), 1);
+  
+  taosHashCleanup(hashTable);
+}
+
+void functionTest() {
+
+}
+
+/**
+ * evaluate the performance issue, by add 10million elements in to hash table in
+ * a single threads situation
+ */
+void noLockPerformanceTest() {
+  auto* hashTable = (SHashObj*) taosHashInit(4096, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BINARY), false);
+  ASSERT_EQ(taosHashGetSize(hashTable), 0);
+  
+  char key[128] = {0};
+  int32_t num = 5000000;
+  
+  int64_t st = taosGetTimestampUs();
+  
+  // put 10M elements in the hash table
+  for(int32_t i = 0; i < num; ++i) {
+    int32_t len = sprintf(key, "%d_1_%dabcefg_", i, i + 10);
+    taosHashPut(hashTable, key, len, (char*) &i, sizeof(int32_t));
+  }
+  
+  ASSERT_EQ(taosHashGetSize(hashTable), num);
+  
+  int64_t et = taosGetTimestampUs();
+  printf("Elpased time:%" PRId64 " us to add %d elements, avg cost:%lf us\n", et - st, num, (et - st)/(double) num);
+  
+  st = taosGetTimestampUs();
+  for(int32_t i = 0; i < num; ++i) {
+    int32_t len = sprintf(key, "%d_1_%dabcefg_", i, i + 10);
+    char* p = (char*) taosHashGet(hashTable, key, len);
+    ASSERT_TRUE(p != nullptr);
+    
+    ASSERT_EQ(*reinterpret_cast<int32_t*>(p), i);
+  }
+  
+  et = taosGetTimestampUs();
+  printf("Elpased time:%" PRId64 " us to fetch all %d elements, avg cost:%lf us\n", et - st, num, (et - st)/(double) num);
+  
+  printf("The maximum length of overflow linklist in hash table is:%d\n", taosHashGetMaxOverflowLinkLength(hashTable));
+  taosHashCleanup(hashTable);
+}
+
+void multithreadsTest() {
+  //todo
+}
+
+// check the function robustness
+void invalidOperationTest() {
+
+}
+
+}
+
+int main(int argc, char** argv) {
+  testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}
+
+TEST(testCase, hashTest) {
+  simpleTest();
+  stringKeyTest();
+  noLockPerformanceTest();
+  multithreadsTest();
+}
\ No newline at end of file
diff --git a/src/util/tests/stringTest.cpp b/src/util/tests/stringTest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..b1b06c7f490fbe8dd5adcb0d442f3e1034833bc1
--- /dev/null
+++ b/src/util/tests/stringTest.cpp
@@ -0,0 +1,178 @@
+#include <gtest/gtest.h>
+#include <limits.h>
+#include <taosdef.h>
+#include <iostream>
+
+#include "taos.h"
+#include "tutil.h"
+
+TEST(testCase, string_dequote_test) {
+  char    t1[] = "'abc'";
+  int32_t len = strdequote(t1);
+
+  EXPECT_EQ(3, len);
+  EXPECT_STRCASEEQ(t1, "abc");
+
+  char t2[] = "\"abc\"";
+  len = strdequote(t2);
+
+  EXPECT_EQ(3, len);
+  EXPECT_STRCASEEQ(t1, "abc");
+
+  char t21[] = " abc ";
+  strtrim(t21);
+
+  EXPECT_STREQ("abc", t21);
+  EXPECT_EQ(3, strlen(t21));
+}
+
+TEST(testCase, string_replace_test) {
+  char  t3[] = "abc01abc02abc";
+  char* ret = strreplace(t3, "abc", "7");
+
+  EXPECT_EQ(strlen(ret), 7);
+  EXPECT_STREQ("7017027", ret);
+  free(ret);
+
+  char t4[] = "a01a02b03c04d05";
+  ret = strreplace(t4, "0", "9999999999");
+
+  EXPECT_EQ(strlen(ret), 5 * 10 + 10);
+  EXPECT_STREQ("a99999999991a99999999992b99999999993c99999999994d99999999995", ret);
+  free(ret);
+
+  char t5[] = "abc";
+  ret = strreplace(t5, "abc", "12345678901234567890");
+
+  EXPECT_EQ(strlen(ret), 20);
+  EXPECT_STREQ("12345678901234567890", ret);
+  free(ret);
+
+  char t6[] = "abc";
+  ret = strreplace(t6, "def", "abc");
+
+  EXPECT_EQ(strlen(ret), 3);
+  EXPECT_STREQ("abc", ret);
+  free(ret);
+
+  char t7[] = "abcde000000000000001234";
+  ret = strreplace(t7, "ab", "0000000");
+
+  EXPECT_EQ(strlen(ret), 28);
+  EXPECT_STREQ("0000000cde000000000000001234", ret);
+  free(ret);
+
+  char t8[] = "abc\ndef";
+  char t[] = {10, 0};
+
+  char    f1[] = "\\n";
+  int32_t fx = strlen(f1);
+  ret = strreplace(t8, "\n", "\\n");
+
+  EXPECT_EQ(strlen(ret), 8);
+  EXPECT_STREQ("abc\\ndef", ret);
+  free(ret);
+
+  char t9[] = "abc\\ndef";
+  ret = strreplace(t9, "\\n", "\n");
+
+  EXPECT_EQ(strlen(ret), 7);
+  EXPECT_STREQ("abc\ndef", ret);
+  free(ret);
+
+  char t10[] = "abcdef";
+  ret = strreplace(t10, "", "0");
+
+  EXPECT_EQ(strlen(ret), 6);
+  EXPECT_STREQ("abcdef", ret);
+  free(ret);
+}
+
+TEST(testCase, string_tolower_test) {
+  char t[1024] = {1};
+  memset(t, 1, tListLen(t));
+
+  const char* a1 = "ABC";
+  strtolower(t, a1);
+  EXPECT_STREQ(t, "abc");
+
+  memset(t, 1, tListLen(t));
+  const char* a2 = "ABC\'ABC\'D";
+  strtolower(t, a2);
+  EXPECT_STREQ(t, "abc\'ABC\'d");
+
+  memset(t, 1, tListLen(t));
+  const char* a3 = "";
+  strtolower(t, a3);
+  EXPECT_STREQ(t, "");
+
+  memset(t, 1, tListLen(t));
+  const char* a4 = "\"AbcDEF\"";
+  strtolower(t, a4);
+  EXPECT_STREQ(t, a4);
+
+  memset(t, 1, tListLen(t));
+  const char* a5 = "1234\"AbcDEF\"456";
+  strtolower(t, a5);
+  EXPECT_STREQ(t, a5);
+
+  memset(t, 1, tListLen(t));
+  const char* a6 = "1234";
+  strtolower(t, a6);
+  EXPECT_STREQ(t, a6);
+}
+
+TEST(testCase, string_strnchr_test) {
+  char t[1024] = {0};
+  memset(t, 1, tListLen(t));
+
+  char a1[] = "AB.C";
+  EXPECT_TRUE(strnchr(a1, '.', strlen(a1), true) != NULL);
+
+  char a2[] = "abc.";
+  EXPECT_TRUE(strnchr(a2, '.', strlen(a2), true) != NULL);
+
+  char a8[] = "abc.";
+  EXPECT_TRUE(strnchr(a8, '.', 1, true) == NULL);
+
+  char a3[] = ".abc";
+  EXPECT_TRUE(strnchr(a3, '.', strlen(a3), true) != NULL);
+
+  char a4[] = "'.abc'";
+  EXPECT_TRUE(strnchr(a4, '.', strlen(a4), true) == NULL);
+
+  char a5[] = "'.abc.'abc";
+  EXPECT_TRUE(strnchr(a5, '.', strlen(a5), true) == NULL);
+
+  char a6[] = "0123456789.";
+  EXPECT_TRUE(strnchr(a6, '.', strlen(a6), true) != NULL);
+
+  char a7[] = "0123456789.";
+  EXPECT_TRUE(strnchr(a7, '.', 3, true) == NULL);
+
+  char a9[] = "0123456789.";
+  EXPECT_TRUE(strnchr(a9, '.', 0, true) == NULL);
+
+  char a10[] = "0123456789'.'";
+  EXPECT_TRUE(strnchr(a10, '.', strlen(a10), true) == NULL);
+}
+
+TEST(testCase, cache_resize_test) {
+  char a11[] = "abc'.'";
+  EXPECT_TRUE(strnchr(a11, '.', strlen(a11), false) != NULL);
+
+  char a12[] = "abc'-'";
+  EXPECT_TRUE(strnchr(a12, '-', strlen(a12), false) != NULL);
+
+  char a15[] = "abc'-'";
+  EXPECT_TRUE(strnchr(a15, '-', strlen(a15), true) == NULL);
+
+  char a13[] = "'-'";
+  EXPECT_TRUE(strnchr(a13, '-', strlen(a13), false) != NULL);
+
+  char a14[] = "'-'";
+  EXPECT_TRUE(strnchr(a14, '-', strlen(a14), true) == NULL);
+
+  char a16[] = "'-'.";
+  EXPECT_TRUE(strnchr(a16, '.', strlen(a16), true) != NULL);
+}
\ No newline at end of file
diff --git a/src/vnode/tsdb/src/tsdbMeta.c b/src/vnode/tsdb/src/tsdbMeta.c
index 761006a0095db206eb7be93fef456a7de1951df3..1dd1c3b29d1dd1d805169e85c39c04d235ad1016 100644
--- a/src/vnode/tsdb/src/tsdbMeta.c
+++ b/src/vnode/tsdb/src/tsdbMeta.c
@@ -349,10 +349,10 @@ static int tsdbAddTableToMeta(STsdbMeta *pMeta, STable *pTable, bool addIdx) {
   } else {
     // add non-super table to the array
     pMeta->tables[pTable->tableId.tid] = pTable;
-    if (pTable->type == TSDB_CHILD_TABLE) {
-      // add STABLE to the index
+    if (pTable->type == TSDB_CHILD_TABLE && addIdx) { // add STABLE to the index
       tsdbAddTableIntoIndex(pMeta, pTable);
     }
+    
     pMeta->nTables++;
   }
 
diff --git a/src/vnode/tsdb/src/tsdbRead.c b/src/vnode/tsdb/src/tsdbRead.c
index 3119fdc7ccc9287fea28b4364cad75e7faa08784..7b996c8f7a170fdf278c1cb844ca85686f65fa6a 100644
--- a/src/vnode/tsdb/src/tsdbRead.c
+++ b/src/vnode/tsdb/src/tsdbRead.c
@@ -73,7 +73,7 @@ typedef struct SQueryFilesInfo {
   char dbFilePathPrefix[PATH_MAX];
 } SQueryFilesInfo;
 
-typedef struct STableQueryInfo {
+typedef struct STableCheckInfo {
   STableId    tableId;
   TSKEY       lastKey;
   STable *    pTableObj;
@@ -81,7 +81,8 @@ typedef struct STableQueryInfo {
   int32_t     numOfBlocks;
   int32_t     start;
   SCompBlock *pBlock;
-} STableQueryInfo;
+  SSkipListIterator* iter;
+} STableCheckInfo;
 
 typedef struct {
   SCompBlock *compBlock;
@@ -90,14 +91,19 @@ typedef struct {
 
 typedef struct STableDataBlockInfoEx {
   SCompBlockFields pBlock;
-  STableQueryInfo* pMeterDataInfo;
+  STableCheckInfo* pMeterDataInfo;
   int32_t          blockIndex;
   int32_t          groupIdx; /* number of group is less than the total number of meters */
 } STableDataBlockInfoEx;
 
+enum {
+  SINGLE_TABLE_MODEL = 1,
+  MULTI_TABLE_MODEL = 2,
+};
+
 typedef struct STsdbQueryHandle {
   struct STsdbRepo* pTsdb;
-  
+  int8_t          model;  // access model, single table model or multi-table model
   SQueryHandlePos cur;    // current position
   SQueryHandlePos start;  // the start position, used for secondary/third iteration
   int32_t         unzipBufSize;
@@ -120,14 +126,13 @@ typedef struct STsdbQueryHandle {
   bool        locateStart;
   int32_t     realNumOfRows;
   bool        loadDataAfterSeek;  // load data after seek.
-  SArray*     pTableQueryInfo;
+  SArray*     pTableCheckInfo;
   int32_t     activeIndex;
   
   int32_t     tableIndex;
   bool        isFirstSlot;
   void *      qinfo;              // query info handle, for debug purpose
   
-  SSkipListIterator*     memIter;
   STableDataBlockInfoEx *pDataBlockInfoEx;
 } STsdbQueryHandle;
 
@@ -271,19 +276,21 @@ tsdb_query_handle_t *tsdbQueryByTableId(tsdb_repo_t* tsdb, STsdbQueryCond *pCond
   size_t size = taosArrayGetSize(idList);
   assert(size >= 1);
 
-  pQueryHandle->pTableQueryInfo = taosArrayInit(size, sizeof(STableQueryInfo));
+  pQueryHandle->pTableCheckInfo = taosArrayInit(size, sizeof(STableCheckInfo));
   for(int32_t i = 0; i < size; ++i) {
     STableId id = *(STableId*) taosArrayGet(idList, i);
     
-    STableQueryInfo info = {
+    STableCheckInfo info = {
       .lastKey = pQueryHandle->window.skey,
       .tableId = id,
       .pTableObj = tsdbGetTableByUid(tsdbGetMeta(tsdb), id.uid),  //todo this may be failed
     };
     
-    taosArrayPush(pQueryHandle->pTableQueryInfo, &info);
+    taosArrayPush(pQueryHandle->pTableCheckInfo, &info);
   }
   
+  pQueryHandle->model = (size > 1)? MULTI_TABLE_MODEL:SINGLE_TABLE_MODEL;
+  
   pQueryHandle->activeIndex = 0;
   
   // malloc buffer in order to load data from file
@@ -314,11 +321,13 @@ tsdb_query_handle_t *tsdbQueryByTableId(tsdb_repo_t* tsdb, STsdbQueryCond *pCond
   return (tsdb_query_handle_t)pQueryHandle;
 }
 
-bool tsdbNextDataBlock(tsdb_query_handle_t *pQueryHandle) {
-  STsdbQueryHandle* pHandle = (STsdbQueryHandle*) pQueryHandle;
-  STableQueryInfo* pTableQInfo = taosArrayGet(pHandle->pTableQueryInfo, pHandle->activeIndex);
+static bool hasMoreDataInCacheForSingleModel(STsdbQueryHandle* pHandle) {
+  assert(pHandle->activeIndex == 0 && taosArrayGetSize(pHandle->pTableCheckInfo) == 1);
   
-  STable *pTable = pTableQInfo->pTableObj;
+  STableCheckInfo* pTableCheckInfo = taosArrayGet(pHandle->pTableCheckInfo, pHandle->activeIndex);
+  
+  STable *pTable = pTableCheckInfo->pTableObj;
+  assert(pTable != NULL);
   
   // no data in cache, abort
   if (pTable->mem == NULL && pTable->imem == NULL) {
@@ -326,13 +335,49 @@ bool tsdbNextDataBlock(tsdb_query_handle_t *pQueryHandle) {
   }
   
   // all data in mem are checked already.
-  if (pTableQInfo->lastKey > pTable->mem->keyLast) {
+  if (pTableCheckInfo->lastKey > pTable->mem->keyLast) {
     return false;
   }
   
   return true;
 }
 
+static bool hasMoreDataInCacheForMultiModel(STsdbQueryHandle* pHandle) {
+  size_t numOfTables = taosArrayGetSize(pHandle->pTableCheckInfo);
+  assert(numOfTables > 0);
+  
+  while(pHandle->activeIndex < numOfTables) {
+    STableCheckInfo* pTableCheckInfo = taosArrayGet(pHandle->pTableCheckInfo, pHandle->activeIndex);
+  
+    STable *pTable = pTableCheckInfo->pTableObj;
+    if (pTable->mem == NULL && pTable->imem == NULL) {
+      pHandle->activeIndex += 1;  // try next table if exits
+      continue;
+    }
+  
+    // all data in mem are checked already.
+    if (pTableCheckInfo->lastKey > pTable->mem->keyLast) {
+      pHandle->activeIndex += 1;  // try next table if exits
+      continue;
+    }
+    
+    return true;
+  }
+  
+  // all tables has checked already
+  return false;
+}
+
+// handle data in cache situation
+bool tsdbNextDataBlock(tsdb_query_handle_t *pQueryHandle) {
+  STsdbQueryHandle* pHandle = (STsdbQueryHandle*) pQueryHandle;
+  if (pHandle->model == SINGLE_TABLE_MODEL) {
+    return hasMoreDataInCacheForSingleModel(pHandle);
+  } else {
+    return hasMoreDataInCacheForMultiModel(pHandle);
+  }
+}
+
 static int tsdbReadRowsFromCache(SSkipListIterator *pIter, TSKEY maxKey, int maxRowsToRead,
     TSKEY* skey, TSKEY* ekey, STsdbQueryHandle* pHandle) {
   int numOfRows = 0;
@@ -370,7 +415,7 @@ static int tsdbReadRowsFromCache(SSkipListIterator *pIter, TSKEY maxKey, int max
 SDataBlockInfo tsdbRetrieveDataBlockInfo(tsdb_query_handle_t *pQueryHandle) {
   STsdbQueryHandle* pHandle = (STsdbQueryHandle*) pQueryHandle;
   
-  STableQueryInfo* pTableQInfo = taosArrayGet(pHandle->pTableQueryInfo, pHandle->activeIndex);
+  STableCheckInfo* pTableQInfo = taosArrayGet(pHandle->pTableCheckInfo, pHandle->activeIndex);
   STable *pTable = pTableQInfo->pTableObj;
   
   TSKEY skey = 0, ekey = 0;
@@ -379,11 +424,11 @@ SDataBlockInfo tsdbRetrieveDataBlockInfo(tsdb_query_handle_t *pQueryHandle) {
   if (pTable->mem != NULL) {
     
     // create mem table iterator if it is not created yet
-    if (pHandle->memIter == NULL) {
-      pHandle->memIter = tSkipListCreateIter(pTable->mem->pData);
+    if (pTableQInfo->iter == NULL) {
+      pTableQInfo->iter = tSkipListCreateIter(pTable->mem->pData);
     }
     
-    rows = tsdbReadRowsFromCache(pHandle->memIter, INT64_MAX, 2, &skey, &ekey, pHandle);
+    rows = tsdbReadRowsFromCache(pTableQInfo->iter, INT64_MAX, 2, &skey, &ekey, pHandle);
   }
   
   SDataBlockInfo blockInfo = {
diff --git a/src/vnode/tsdb/tests/CMakeLists.txt b/src/vnode/tsdb/tests/CMakeLists.txt
index 51c15bce203eb920d7f377d261322047ccd008dc..ee1aaba8cd8c623b29f2d1200c640da2a62dfe6e 100644
--- a/src/vnode/tsdb/tests/CMakeLists.txt
+++ b/src/vnode/tsdb/tests/CMakeLists.txt
@@ -3,9 +3,4 @@ aux_source_directory(${CMAKE_CURRENT_SOURCE_DIR} SOURCE_LIST)
 add_executable(tsdbTests ${SOURCE_LIST})
 target_link_libraries(tsdbTests gtest gtest_main pthread common tsdb)
 
-add_test(
-    NAME
-      unit   
-    COMMAND
-      ${CMAKE_CURRENT_BINARY_DIR}/tsdbTests
-)
\ No newline at end of file
+add_test(NAME unit COMMAND ${CMAKE_CURRENT_BINARY_DIR}/tsdbTests)
\ No newline at end of file