diff --git a/src/client/inc/tscUtil.h b/src/client/inc/tscUtil.h
index b15286fe80..af91ac34f0 100644
--- a/src/client/inc/tscUtil.h
+++ b/src/client/inc/tscUtil.h
@@ -277,6 +277,9 @@ void tscAsyncQuerySingleRowForNextVnode(void *param, TAOS_RES *tres, int numOfRo
 void tscTryQueryNextClause(SSqlObj* pSql, __async_cb_func_t fp);
 int  tscSetMgmtEpSetFromCfg(const char *first, const char *second);
 
+bool tscSetSqlOwner(SSqlObj* pSql);
+void tscClearSqlOwner(SSqlObj* pSql);
+
 void* malloc_throw(size_t size);
 void* calloc_throw(size_t nmemb, size_t size);
 char* strdup_throw(const char* str);
diff --git a/src/client/inc/tsclient.h b/src/client/inc/tsclient.h
index b38e6377a9..6d02bc7fbd 100644
--- a/src/client/inc/tsclient.h
+++ b/src/client/inc/tsclient.h
@@ -80,8 +80,9 @@ typedef struct STableMetaInfo {
    * 2. keep the vgroup index for multi-vnode insertion
    */
   int32_t vgroupIndex;
-  char    name[TSDB_TABLE_ID_LEN];        // (super) table name
-  SArray* tagColList;                     // SArray<SColumn*>, involved tag columns
+  char    name[TSDB_TABLE_FNAME_LEN];        // (super) table name
+  char    aliasName[TSDB_TABLE_NAME_LEN];    // alias name of table specified in query sql
+  SArray* tagColList;                        // SArray<SColumn*>, involved tag columns
 } STableMetaInfo;
 
 /* the structure for sql function in select clause */
@@ -106,7 +107,7 @@ typedef struct SColumnIndex {
 typedef struct SFieldSupInfo {
   bool            visible;
   SExprInfo      *pArithExprInfo;
-  SSqlExpr *      pSqlExpr;
+  SSqlExpr       *pSqlExpr;
 } SFieldSupInfo;
 
 typedef struct SFieldInfo {
@@ -128,7 +129,7 @@ typedef struct SCond {
 } SCond;
 
 typedef struct SJoinNode {
-  char     tableId[TSDB_TABLE_ID_LEN];
+  char     tableId[TSDB_TABLE_FNAME_LEN];
   uint64_t uid;
   int16_t  tagColId;
 } SJoinNode;
@@ -162,7 +163,7 @@ typedef struct SParamInfo {
 } SParamInfo;
 
 typedef struct STableDataBlocks {
-  char     tableId[TSDB_TABLE_ID_LEN];
+  char     tableId[TSDB_TABLE_FNAME_LEN];
   int8_t   tsSource;     // where does the UNIX timestamp come from, server or client
   bool     ordered;      // if current rows are ordered or not
   int64_t  vgId;         // virtual group id
@@ -255,6 +256,7 @@ typedef struct SResRec {
 
 typedef struct {
   int64_t               numOfRows;                  // num of results in current retrieved
+  int64_t               numOfRowsGroup;             // num of results of current group
   int64_t               numOfTotal;                 // num of total results
   int64_t               numOfClauseTotal;           // num of total result in current subclause
   char *                pRsp;
@@ -301,6 +303,7 @@ typedef struct STscObj {
 
 typedef struct SSqlObj {
   void            *signature;
+  pthread_t        owner;        // owner of sql object, by which it is executed
   STscObj         *pTscObj;
   void            *pRpcCtx;
   void            (*fp)();
@@ -419,7 +422,6 @@ char *tscGetErrorMsgPayload(SSqlCmd *pCmd);
 int32_t tscInvalidSQLErrMsg(char *msg, const char *additionalInfo, const char *sql);
 
 int32_t tscToSQLCmd(SSqlObj *pSql, struct SSqlInfo *pInfo);
-//void    tscGetResultColumnChr(SSqlRes *pRes, SFieldInfo* pFieldInfo, int32_t column);
 
 static FORCE_INLINE void tscGetResultColumnChr(SSqlRes* pRes, SFieldInfo* pFieldInfo, int32_t columnIndex) {
   SFieldSupInfo* pInfo = (SFieldSupInfo*) TARRAY_GET_ELEM(pFieldInfo->pSupportInfo, columnIndex);
diff --git a/src/client/src/tscAsync.c b/src/client/src/tscAsync.c
index 759c6e5e1e..b05aef76eb 100644
--- a/src/client/src/tscAsync.c
+++ b/src/client/src/tscAsync.c
@@ -220,14 +220,13 @@ void taos_fetch_rows_a(TAOS_RES *taosa, void (*fp)(void *, TAOS_RES *, int), voi
   if (pCmd->command == TSDB_SQL_TABLE_JOIN_RETRIEVE) {
     tscFetchDatablockFromSubquery(pSql);
   } else if (pRes->completed) {
-    if(pCmd->command == TSDB_SQL_FETCH) {
+    if(pCmd->command == TSDB_SQL_FETCH || (pCmd->command >= TSDB_SQL_SERV_STATUS && pCmd->command <= TSDB_SQL_CURRENT_USER)) {
       if (hasMoreVnodesToTry(pSql)) {  // sequentially retrieve data from remain vnodes.
         tscTryQueryNextVnode(pSql, tscAsyncQueryRowsForNextVnode);
-        return;
       } else {
         /*
-       * all available virtual node has been checked already, now we need to check
-       * for the next subclause queries
+         * all available virtual nodes in current clause has been checked already, now try the
+         * next one in the following union subclause
          */
         if (pCmd->clauseIndex < pCmd->numOfClause - 1) {
           tscTryQueryNextClause(pSql, tscAsyncQueryRowsForNextVnode);
@@ -235,11 +234,12 @@ void taos_fetch_rows_a(TAOS_RES *taosa, void (*fp)(void *, TAOS_RES *, int), voi
         }
 
         /*
-       * 1. has reach the limitation
-       * 2. no remain virtual nodes to be retrieved anymore
+         * 1. has reach the limitation
+         * 2. no remain virtual nodes to be retrieved anymore
          */
         (*pSql->fetchFp)(param, pSql, 0);
       }
+
       return;
     } else if (pCmd->command == TSDB_SQL_RETRIEVE || pCmd->command == TSDB_SQL_RETRIEVE_LOCALMERGE) {
       // in case of show command, return no data
diff --git a/src/client/src/tscFunctionImpl.c b/src/client/src/tscFunctionImpl.c
index 9c0951cdd6..5c708dffee 100644
--- a/src/client/src/tscFunctionImpl.c
+++ b/src/client/src/tscFunctionImpl.c
@@ -1942,11 +1942,12 @@ static void do_top_function_add(STopBotInfo *pInfo, int32_t maxLen, void *pData,
 
 static void do_bottom_function_add(STopBotInfo *pInfo, int32_t maxLen, void *pData, int64_t ts, uint16_t type,
                                    SExtTagsInfo *pTagInfo, char *pTags, int16_t stage) {
-  tValuePair **pList = pInfo->res;
-  
   tVariant val = {0};
   tVariantCreateFromBinary(&val, pData, tDataTypeDesc[type].nSize, type);
-  
+
+  tValuePair **pList = pInfo->res;
+  assert(pList != NULL);
+
   if (pInfo->num < maxLen) {
     if (pInfo->num == 0) {
       valuePairAssign(pList[pInfo->num], type, (const char*) &val.i64Key, ts, pTags, pTagInfo, stage);
diff --git a/src/client/src/tscLocal.c b/src/client/src/tscLocal.c
index a56a01ba02..caaaa5bc18 100644
--- a/src/client/src/tscLocal.c
+++ b/src/client/src/tscLocal.c
@@ -293,7 +293,7 @@ static void tscProcessCurrentDB(SSqlObj *pSql) {
   char db[TSDB_DB_NAME_LEN] = {0};
   extractDBName(pSql->pTscObj->db, db);
   
-  SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(&pSql->cmd, 0);
+  SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(&pSql->cmd, pSql->cmd.clauseIndex);
   
   SSqlExpr* pExpr = taosArrayGetP(pQueryInfo->exprList, 0);
   pExpr->resType = TSDB_DATA_TYPE_BINARY;
@@ -314,7 +314,7 @@ static void tscProcessCurrentDB(SSqlObj *pSql) {
 
 static void tscProcessServerVer(SSqlObj *pSql) {
   const char* v = pSql->pTscObj->sversion;
-  SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(&pSql->cmd, 0);
+  SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(&pSql->cmd, pSql->cmd.clauseIndex);
   
   SSqlExpr* pExpr = taosArrayGetP(pQueryInfo->exprList, 0);
   pExpr->resType = TSDB_DATA_TYPE_BINARY;
diff --git a/src/client/src/tscLocalMerge.c b/src/client/src/tscLocalMerge.c
index b7d8a0b7b2..5955515bbd 100644
--- a/src/client/src/tscLocalMerge.c
+++ b/src/client/src/tscLocalMerge.c
@@ -68,7 +68,7 @@ static void tscInitSqlContext(SSqlCmd *pCmd, SLocalReducer *pReducer, tOrderDesc
     SSqlExpr *      pExpr = tscSqlExprGet(pQueryInfo, i);
 
     pCtx->aOutputBuf =
-        pReducer->pResultBuf->data + tscFieldInfoGetOffset(pQueryInfo, i) * pReducer->resColModel->capacity;
+        pReducer->pResultBuf->data + pExpr->offset * pReducer->resColModel->capacity;
     pCtx->order = pQueryInfo->order.order;
     pCtx->functionId = pExpr->functionId;
 
@@ -321,6 +321,7 @@ void tscCreateLocalReducer(tExtMemBuffer **pMemBuffer, int32_t numOfBuffer, tOrd
   pReducer->finalRowSize = tscGetResRowLength(pQueryInfo->exprList);
   pReducer->resColModel = finalmodel;
   pReducer->resColModel->capacity = pReducer->nResultBufSize;
+
   assert(pReducer->finalRowSize > 0);
   if (pReducer->finalRowSize > 0) {
     pReducer->resColModel->capacity /= pReducer->finalRowSize;
@@ -328,7 +329,6 @@ void tscCreateLocalReducer(tExtMemBuffer **pMemBuffer, int32_t numOfBuffer, tOrd
   assert(pReducer->finalRowSize <= pReducer->rowSize);
 
   pReducer->pFinalRes = calloc(1, pReducer->rowSize * pReducer->resColModel->capacity);
-//  pReducer->pBufForInterpo = calloc(1, pReducer->nResultBufSize);
 
   if (pReducer->pTempBuffer == NULL || pReducer->discardData == NULL || pReducer->pResultBuf == NULL ||
       /*pReducer->pBufForInterpo == NULL || */pReducer->pFinalRes == NULL || pReducer->prevRowOfInput == NULL) {
@@ -856,24 +856,6 @@ void savePrevRecordAndSetupInterpoInfo(SLocalReducer *pLocalReducer, SQueryInfo
   tColModelAppend(pModel, pLocalReducer->discardData, pLocalReducer->prevRowOfInput, 0, 1, 1);
 }
 
-// todo merge with following function
-// static void reversedCopyResultToDstBuf(SQueryInfo* pQueryInfo, SSqlRes *pRes, tFilePage *pFinalDataPage) {
-//
-//  for (int32_t i = 0; i < pQueryInfo->exprList.numOfExprs; ++i) {
-//    TAOS_FIELD *pField = tscFieldInfoGetField(&pQueryInfo->fieldsInfo, i);
-//
-//    int32_t offset = tscFieldInfoGetOffset(pQueryInfo, i);
-//    char *  src = pFinalDataPage->data + (pRes->numOfRows - 1) * pField->bytes + pRes->numOfRows * offset;
-//    char *  dst = pRes->data + pRes->numOfRows * offset;
-//
-//    for (int32_t j = 0; j < pRes->numOfRows; ++j) {
-//      memcpy(dst, src, (size_t)pField->bytes);
-//      dst += pField->bytes;
-//      src -= pField->bytes;
-//    }
-//  }
-//}
-
 static void reversedCopyFromInterpolationToDstBuf(SQueryInfo *pQueryInfo, SSqlRes *pRes, tFilePage **pResPages,
                                                   SLocalReducer *pLocalReducer) {
   assert(0);
@@ -907,20 +889,10 @@ static void doFillResult(SSqlObj *pSql, SLocalReducer *pLocalReducer, bool doneO
   tFilePage * pFinalDataPage = pLocalReducer->pResultBuf;
   SQueryInfo *pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);
 
-//  if (pRes->pLocalReducer != pLocalReducer) {
-//    /*
-//     * Release the SSqlObj is called, and it is int destroying function invoked by other thread.
-//     * However, the other thread will WAIT until current process fully completes.
-//     * Since the flag of release struct is set by doLocalReduce function
-//     */
-//    assert(pRes->pLocalReducer == NULL);
-//  }
-
   // no interval query, no fill operation
   if (pQueryInfo->intervalTime == 0 || pQueryInfo->fillType == TSDB_FILL_NONE) {
     pRes->data = pLocalReducer->pFinalRes;
     pRes->numOfRows = pFinalDataPage->num;
-    pRes->numOfClauseTotal += pRes->numOfRows;
 
     if (pQueryInfo->limit.offset > 0) {
       if (pQueryInfo->limit.offset < pRes->numOfRows) {
@@ -931,22 +903,22 @@ static void doFillResult(SSqlObj *pSql, SLocalReducer *pLocalReducer, bool doneO
         tColModelCompact(pLocalReducer->resColModel, pFinalDataPage, prevSize);
 
         pRes->numOfRows -= pQueryInfo->limit.offset;
-        pRes->numOfClauseTotal -= pQueryInfo->limit.offset;
         pQueryInfo->limit.offset = 0;
       } else {
         pQueryInfo->limit.offset -= pRes->numOfRows;
         pRes->numOfRows = 0;
-        pRes->numOfClauseTotal = 0;
       }
     }
 
-    if (pQueryInfo->limit.limit >= 0 && pRes->numOfClauseTotal > pQueryInfo->limit.limit) {
+    pRes->numOfRowsGroup += pRes->numOfRows;
+
+    if (pQueryInfo->limit.limit >= 0 && pRes->numOfRowsGroup > pQueryInfo->limit.limit) {
       /* impose the limitation of output rows on the final result */
-      int32_t prevSize = (int32_t)pFinalDataPage->num;
-      int32_t overflow = (int32_t)(pRes->numOfClauseTotal - pQueryInfo->limit.limit);
+      int32_t prevSize = pFinalDataPage->num;
+      int32_t overflow = pRes->numOfRowsGroup - pQueryInfo->limit.limit;
       assert(overflow < pRes->numOfRows);
 
-      pRes->numOfClauseTotal = pQueryInfo->limit.limit;
+      pRes->numOfRowsGroup = pQueryInfo->limit.limit;
       pRes->numOfRows -= overflow;
       pFinalDataPage->num -= overflow;
 
@@ -957,6 +929,8 @@ static void doFillResult(SSqlObj *pSql, SLocalReducer *pLocalReducer, bool doneO
     }
 
     memcpy(pRes->data, pFinalDataPage->data, pRes->numOfRows * pLocalReducer->finalRowSize);
+
+    pRes->numOfClauseTotal += pRes->numOfRows;
     pFinalDataPage->num = 0;
     return;
   }
@@ -969,7 +943,7 @@ static void doFillResult(SSqlObj *pSql, SLocalReducer *pLocalReducer, bool doneO
     TAOS_FIELD *pField = tscFieldInfoGetField(&pQueryInfo->fieldsInfo, i);
     pResPages[i] = calloc(1, sizeof(tFilePage) + pField->bytes * pLocalReducer->resColModel->capacity);
   }
-  
+
   while (1) {
     int64_t newRows = taosGenerateDataBlock(pFillInfo, pResPages, pLocalReducer->resColModel->capacity);
 
@@ -986,7 +960,6 @@ static void doFillResult(SSqlObj *pSql, SLocalReducer *pLocalReducer, bool doneO
 
       pRes->data = pLocalReducer->pFinalRes;
       pRes->numOfRows = newRows;
-      pRes->numOfClauseTotal += newRows;
 
       pQueryInfo->limit.offset = 0;
       break;
@@ -1010,15 +983,13 @@ static void doFillResult(SSqlObj *pSql, SLocalReducer *pLocalReducer, bool doneO
   }
 
   if (pRes->numOfRows > 0) {
-    if (pQueryInfo->limit.limit >= 0 && pRes->numOfClauseTotal > pQueryInfo->limit.limit) {
-      int32_t overflow = (int32_t)(pRes->numOfClauseTotal - pQueryInfo->limit.limit);
+    if (pQueryInfo->limit.limit >= 0 && pRes->numOfRows > pQueryInfo->limit.limit) {
+      int32_t overflow = pRes->numOfRows - pQueryInfo->limit.limit;
       pRes->numOfRows -= overflow;
-
-      assert(pRes->numOfRows >= 0);
-
-      pRes->numOfClauseTotal = pQueryInfo->limit.limit;
       pFinalDataPage->num -= overflow;
 
+      assert(pRes->numOfRows >= 0 && pFinalDataPage->num > 0);
+
       /* set remain data to be discarded, and reset the interpolation information */
       savePrevRecordAndSetupInterpoInfo(pLocalReducer, pQueryInfo, pFillInfo);
     }
@@ -1032,6 +1003,9 @@ static void doFillResult(SSqlObj *pSql, SLocalReducer *pLocalReducer, bool doneO
     } else {  // todo bug??
       reversedCopyFromInterpolationToDstBuf(pQueryInfo, pRes, pResPages, pLocalReducer);
     }
+
+    pRes->numOfRowsGroup += pRes->numOfRows;
+    pRes->numOfClauseTotal += pRes->numOfRows;
   }
 
   pFinalDataPage->num = 0;
@@ -1227,7 +1201,10 @@ static bool saveGroupResultInfo(SSqlObj *pSql) {
   SSqlRes *pRes = &pSql->res;
 
   SQueryInfo *pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);
-  pRes->numOfGroups += 1;
+
+  if (pRes->numOfRowsGroup > 0) {
+    pRes->numOfGroups += 1;
+  }
 
   // the output group is limited by the slimit clause
   if (reachGroupResultLimit(pQueryInfo, pRes)) {
@@ -1266,7 +1243,12 @@ bool doGenerateFinalResults(SSqlObj *pSql, SLocalReducer *pLocalReducer, bool no
     pRes->numOfRows = 0;
     pQueryInfo->slimit.offset -= 1;
     pLocalReducer->discard = !noMoreCurrentGroupRes;
-    
+
+    if (pLocalReducer->discard) {
+      SColumnModel *pInternModel = pLocalReducer->pDesc->pColumnModel;
+      tColModelAppend(pInternModel, pLocalReducer->discardData, pLocalReducer->pTempBuffer->data, 0, 1, 1);
+    }
+
     return false;
   }
 
@@ -1299,7 +1281,7 @@ void resetOutputBuf(SQueryInfo *pQueryInfo, SLocalReducer *pLocalReducer) {  //
 static void resetEnvForNewResultset(SSqlRes *pRes, SSqlCmd *pCmd, SLocalReducer *pLocalReducer) {
   // In handling data in other groups, we need to reset the interpolation information for a new group data
   pRes->numOfRows = 0;
-  pRes->numOfClauseTotal = 0;
+  pRes->numOfRowsGroup = 0;
 
   SQueryInfo *pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);
 
@@ -1363,7 +1345,8 @@ static bool doHandleLastRemainData(SSqlObj *pSql) {
   if ((isAllSourcesCompleted(pLocalReducer) && !pLocalReducer->hasPrevRow) || pLocalReducer->pLocalDataSrc[0] == NULL ||
       prevGroupCompleted) {
     // if fillType == TSDB_FILL_NONE, return directly
-    if (pQueryInfo->fillType != TSDB_FILL_NONE) {
+    if (pQueryInfo->fillType != TSDB_FILL_NONE &&
+      ((pRes->numOfRowsGroup < pQueryInfo->limit.limit && pQueryInfo->limit.limit > 0) || (pQueryInfo->limit.limit < 0))) {
       int64_t etime = (pQueryInfo->window.skey < pQueryInfo->window.ekey) ? pQueryInfo->window.ekey : pQueryInfo->window.skey;
 
       assert(pFillInfo->numOfRows == 0);
diff --git a/src/client/src/tscParseInsert.c b/src/client/src/tscParseInsert.c
index 33c8799624..e97d6c32e0 100644
--- a/src/client/src/tscParseInsert.c
+++ b/src/client/src/tscParseInsert.c
@@ -989,7 +989,7 @@ static int32_t tscCheckIfCreateTable(char **sqlstr, SSqlObj *pSql) {
 }
 
 int validateTableName(char *tblName, int len, SSQLToken* psTblToken) {
-  tstrncpy(psTblToken->z, tblName, TSDB_TABLE_ID_LEN);
+  tstrncpy(psTblToken->z, tblName, TSDB_TABLE_FNAME_LEN);
 
   psTblToken->n    = len;
   psTblToken->type = TK_ID;
@@ -1038,7 +1038,7 @@ int tsParseInsertSql(SSqlObj *pSql) {
   }
 
   if (NULL == pCmd->pTableList) {
-    pCmd->pTableList = taosHashInit(128, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BIGINT), false);
+    pCmd->pTableList = taosHashInit(128, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BIGINT), true, false);
     pCmd->pDataBlocks = taosArrayInit(4, POINTER_BYTES);
     if (NULL == pCmd->pTableList || NULL == pSql->cmd.pDataBlocks) {
       code = TSDB_CODE_TSC_OUT_OF_MEMORY;
@@ -1077,7 +1077,7 @@ int tsParseInsertSql(SSqlObj *pSql) {
     }
 
     pCmd->curSql = sToken.z;
-    char buf[TSDB_TABLE_ID_LEN];
+    char buf[TSDB_TABLE_FNAME_LEN];
     SSQLToken sTblToken;
     sTblToken.z = buf;
     // Check if the table name available or not
diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index bc33aac174..1a97a9a997 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -86,7 +86,7 @@ static int32_t parseOrderbyClause(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SQueryS
 static int32_t tsRewriteFieldNameIfNecessary(SSqlCmd* pCmd, SQueryInfo* pQueryInfo);
 static int32_t setAlterTableInfo(SSqlObj* pSql, struct SSqlInfo* pInfo);
 static int32_t validateSqlFunctionInStreamSql(SSqlCmd* pCmd, SQueryInfo* pQueryInfo);
-static int32_t buildArithmeticExprString(tSQLExpr* pExpr, char** exprString);
+static int32_t arithmeticExprToString(tSQLExpr* pExpr, char** exprString);
 static int32_t validateFunctionsInIntervalOrGroupbyQuery(SSqlCmd* pCmd, SQueryInfo* pQueryInfo);
 static int32_t validateArithmeticSQLExpr(SSqlCmd* pCmd, tSQLExpr* pExpr, SQueryInfo* pQueryInfo, SColumnList* pList, int32_t* type);
 static int32_t validateEp(char* ep);
@@ -1087,11 +1087,11 @@ int32_t setObjFullName(char* fullName, const char* account, SSQLToken* pDB, SSQL
     *xlen = totalLen;
   }
 
-  if (totalLen < TSDB_TABLE_ID_LEN) {
+  if (totalLen < TSDB_TABLE_FNAME_LEN) {
     fullName[totalLen] = 0;
   }
 
-  return (totalLen < TSDB_TABLE_ID_LEN) ? TSDB_CODE_SUCCESS : TSDB_CODE_TSC_INVALID_SQL;
+  return (totalLen < TSDB_TABLE_FNAME_LEN) ? TSDB_CODE_SUCCESS : TSDB_CODE_TSC_INVALID_SQL;
 }
 
 static void extractColumnNameFromString(tSQLExprItem* pItem) {
@@ -1106,23 +1106,138 @@ static void extractColumnNameFromString(tSQLExprItem* pItem) {
   }
 }
 
+static int32_t handleArithmeticExpr(SSqlCmd* pCmd, int32_t clauseIndex, int32_t exprIndex, tSQLExprItem* pItem) {
+  const char* msg1 = "invalid column name, or illegal column type";
+  const char* msg2 = "invalid arithmetic expression in select clause";
+  const char* msg3 = "tag columns can not be used in arithmetic expression";
+  const char* msg4 = "columns from different table mixed up in arithmetic expression";
+
+  // arithmetic function in select clause
+  SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, clauseIndex);
+
+  SColumnList columnList = {0};
+  int32_t     arithmeticType = NON_ARITHMEIC_EXPR;
+
+  if (validateArithmeticSQLExpr(pCmd, pItem->pNode, pQueryInfo, &columnList, &arithmeticType) != TSDB_CODE_SUCCESS) {
+    return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg1);
+  }
+
+  int32_t tableIndex = columnList.ids[0].tableIndex;
+
+  // todo potential data overflow
+  char  arithmeticExprStr[1024*12];
+  char* p = arithmeticExprStr;
+
+  if (arithmeticType == NORMAL_ARITHMETIC) {
+    pQueryInfo->type |= TSDB_QUERY_TYPE_PROJECTION_QUERY;
+
+    // all columns in arithmetic expression must belong to the same table
+    for (int32_t f = 1; f < columnList.num; ++f) {
+      if (columnList.ids[f].tableIndex != tableIndex) {
+        return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg4);
+      }
+    }
+
+    if (arithmeticExprToString(pItem->pNode, &p) != TSDB_CODE_SUCCESS) {
+      return TSDB_CODE_TSC_INVALID_SQL;
+    }
+
+    // expr string is set as the parameter of function
+    SColumnIndex index = {.tableIndex = tableIndex};
+
+    SSqlExpr* pExpr = tscSqlExprAppend(pQueryInfo, TSDB_FUNC_ARITHM, &index, TSDB_DATA_TYPE_DOUBLE, sizeof(double),
+                                       sizeof(double), false);
+
+    char* name = (pItem->aliasName != NULL)? pItem->aliasName:arithmeticExprStr;
+    tstrncpy(pExpr->aliasName, name, sizeof(pExpr->aliasName));
+
+    tExprNode* pNode = NULL;
+    SArray* colList = taosArrayInit(10, sizeof(SColIndex));
+
+    int32_t ret = exprTreeFromSqlExpr(pCmd, &pNode, pItem->pNode, pQueryInfo->exprList, pQueryInfo, colList);
+    if (ret != TSDB_CODE_SUCCESS) {
+      tExprTreeDestroy(&pNode, NULL);
+      return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg2);
+    }
+
+    size_t numOfNode = taosArrayGetSize(colList);
+    for(int32_t k = 0; k < numOfNode; ++k) {
+      SColIndex* pIndex = taosArrayGet(colList, k);
+      if (pIndex->flag == 1) {
+        return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg3);
+      }
+    }
+
+    SBufferWriter bw = tbufInitWriter(NULL, false);
+
+    TRY(0) {
+        exprTreeToBinary(&bw, pNode);
+      } CATCH(code) {
+        tbufCloseWriter(&bw);
+        UNUSED(code);
+        // TODO: other error handling
+      } END_TRY
+
+    size_t len = tbufTell(&bw);
+    char* c = tbufGetData(&bw, true);
+
+    // set the serialized binary string as the parameter of arithmetic expression
+    addExprParams(pExpr, c, TSDB_DATA_TYPE_BINARY, len, index.tableIndex);
+
+    insertResultField(pQueryInfo, exprIndex, &columnList, sizeof(double), TSDB_DATA_TYPE_DOUBLE, pExpr->aliasName, pExpr);
+
+    taosArrayDestroy(colList);
+    tExprTreeDestroy(&pNode, NULL);
+  } else {
+    if (arithmeticExprToString(pItem->pNode, &p) != TSDB_CODE_SUCCESS) {
+      return TSDB_CODE_TSC_INVALID_SQL;
+    }
+
+    columnList.num = 0;
+    columnList.ids[0] = (SColumnIndex) {0, 0};
+
+    char* name = (pItem->aliasName != NULL)? pItem->aliasName:arithmeticExprStr;
+    insertResultField(pQueryInfo, exprIndex, &columnList, sizeof(double), TSDB_DATA_TYPE_DOUBLE, name, NULL);
+
+    int32_t slot = tscNumOfFields(pQueryInfo) - 1;
+    SFieldSupInfo* pInfo = tscFieldInfoGetSupp(&pQueryInfo->fieldsInfo, slot);
+
+    if (pInfo->pSqlExpr == NULL) {
+      SExprInfo* pArithExprInfo = calloc(1, sizeof(SExprInfo));
+
+      // arithmetic expression always return result in the format of double float
+      pArithExprInfo->bytes = sizeof(double);
+      pArithExprInfo->interBytes = sizeof(double);
+      pArithExprInfo->type = TSDB_DATA_TYPE_DOUBLE;
+
+      int32_t ret = exprTreeFromSqlExpr(pCmd, &pArithExprInfo->pExpr, pItem->pNode, pQueryInfo->exprList, pQueryInfo, NULL);
+      if (ret != TSDB_CODE_SUCCESS) {
+        tExprTreeDestroy(&pArithExprInfo->pExpr, NULL);
+        return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), "invalid expression in select clause");
+      }
+
+      pInfo->pArithExprInfo = pArithExprInfo;
+    }
+  }
+
+  return TSDB_CODE_SUCCESS;
+}
+
 int32_t parseSelectClause(SSqlCmd* pCmd, int32_t clauseIndex, tSQLExprList* pSelection, bool isSTable) {
   assert(pSelection != NULL && pCmd != NULL);
 
-  const char* msg1 = "invalid column name, or illegal column type";
   const char* msg2 = "functions can not be mixed up";
   const char* msg3 = "not support query expression";
-  const char* msg4 = "columns from different table mixed up in arithmetic expression";
   const char* msg5 = "invalid function name";
 
   SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, clauseIndex);
-  
+
   if (pQueryInfo->colList == NULL) {
     pQueryInfo->colList = taosArrayInit(4, POINTER_BYTES);
   }
-  
+
   for (int32_t i = 0; i < pSelection->nExpr; ++i) {
-    int32_t outputIndex = (int32_t)tscSqlExprNumOfExprs(pQueryInfo);
+    int32_t outputIndex = tscSqlExprNumOfExprs(pQueryInfo);
     tSQLExprItem* pItem = &pSelection->a[i];
 
     // project on all fields
@@ -1147,96 +1262,11 @@ int32_t parseSelectClause(SSqlCmd* pCmd, int32_t clauseIndex, tSQLExprList* pSel
       }
 
     } else if (pItem->pNode->nSQLOptr >= TK_PLUS && pItem->pNode->nSQLOptr <= TK_REM) {
-      // arithmetic function in select clause
-      SColumnList columnList = {0};
-      int32_t     arithmeticType = NON_ARITHMEIC_EXPR;
-
-      if (validateArithmeticSQLExpr(pCmd, pItem->pNode, pQueryInfo, &columnList, &arithmeticType) != TSDB_CODE_SUCCESS) {
-        return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg1);
+      int32_t code = handleArithmeticExpr(pCmd, clauseIndex, i, pItem);
+      if (code != TSDB_CODE_SUCCESS) {
+        return code;
       }
-      
-      int32_t tableIndex = columnList.ids[0].tableIndex;
-      char  arithmeticExprStr[1024] = {0};
-      char* p = arithmeticExprStr;
-      
-      if (arithmeticType == NORMAL_ARITHMETIC) {
-        pQueryInfo->type |= TSDB_QUERY_TYPE_PROJECTION_QUERY;
-  
-        // all columns in arithmetic expression must belong to the same table
-        for (int32_t f = 1; f < columnList.num; ++f) {
-          if (columnList.ids[f].tableIndex != tableIndex) {
-            return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg4);
-          }
-        }
-  
-        if (buildArithmeticExprString(pItem->pNode, &p) != TSDB_CODE_SUCCESS) {
-          return TSDB_CODE_TSC_INVALID_SQL;
-        }
-  
-        // expr string is set as the parameter of function
-        SColumnIndex index = {.tableIndex = tableIndex};
-        SSqlExpr*    pExpr = tscSqlExprAppend(pQueryInfo, TSDB_FUNC_ARITHM, &index, TSDB_DATA_TYPE_DOUBLE,
-                                              sizeof(double), sizeof(double), false);
-        
-        /* todo alias name should use the original sql string */
-        char* name = (pItem->aliasName != NULL)? pItem->aliasName:arithmeticExprStr;
-        tstrncpy(pExpr->aliasName, name, sizeof(pExpr->aliasName));
-        
-        tExprNode* pNode = NULL;
-        SArray* colList = taosArrayInit(10, sizeof(SColIndex));
-        
-        int32_t ret = exprTreeFromSqlExpr(pCmd, &pNode, pItem->pNode, pQueryInfo->exprList, pQueryInfo, colList);
-        if (ret != TSDB_CODE_SUCCESS) {
-          tExprTreeDestroy(&pNode, NULL);
-          return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), "invalid arithmetic expression in select clause");
-        }
-        
-        SBufferWriter bw = tbufInitWriter(NULL, false);
 
-        TRY(0) {
-          exprTreeToBinary(&bw, pNode);
-        } CATCH(code) {
-          tbufCloseWriter(&bw);
-          UNUSED(code);
-          // TODO: other error handling
-        } END_TRY
-        
-        size_t len = tbufTell(&bw);
-        char* c = tbufGetData(&bw, true);
-        
-        // set the serialized binary string as the parameter of arithmetic expression
-        addExprParams(pExpr, c, TSDB_DATA_TYPE_BINARY, (int32_t)len, index.tableIndex);
-        
-        insertResultField(pQueryInfo, i, &columnList, sizeof(double), TSDB_DATA_TYPE_DOUBLE, pExpr->aliasName, pExpr);
-        
-        taosArrayDestroy(colList);
-        tExprTreeDestroy(&pNode, NULL);
-      } else {
-        columnList.num = 0;
-        columnList.ids[0] = (SColumnIndex) {0, 0};
-        
-        insertResultField(pQueryInfo, i, &columnList, sizeof(double), TSDB_DATA_TYPE_DOUBLE, "dummy_column", NULL);
-        
-        int32_t slot = tscNumOfFields(pQueryInfo) - 1;
-        SFieldSupInfo* pInfo = tscFieldInfoGetSupp(&pQueryInfo->fieldsInfo, slot);
-        
-        if (pInfo->pSqlExpr == NULL) {
-          SExprInfo* pArithExprInfo = calloc(1, sizeof(SExprInfo));
-          
-          // arithmetic expression always return result in the format of double float
-          pArithExprInfo->bytes = sizeof(double);
-          pArithExprInfo->interBytes = sizeof(double);
-          pArithExprInfo->type = TSDB_DATA_TYPE_DOUBLE;
-
-          int32_t ret = exprTreeFromSqlExpr(pCmd, &pArithExprInfo->pExpr, pItem->pNode, pQueryInfo->exprList, pQueryInfo, NULL);
-          if (ret != TSDB_CODE_SUCCESS) {
-            tExprTreeDestroy(&pArithExprInfo->pExpr, NULL);
-            return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), "invalid expression in select clause");
-          }
-  
-          pInfo->pArithExprInfo = pArithExprInfo;
-        }
-      }
     } else {
       /*
        * not support such expression
@@ -2106,13 +2136,10 @@ int32_t getTableIndexImpl(SSQLToken* pTableToken, SQueryInfo* pQueryInfo, SColum
   }
 
   pIndex->tableIndex = COLUMN_INDEX_INITIAL_VAL;
-  char tableName[TSDB_TABLE_ID_LEN] = {0};
-
   for (int32_t i = 0; i < pQueryInfo->numOfTables; ++i) {
     STableMetaInfo* pTableMetaInfo = tscGetMetaInfo(pQueryInfo, i);
-    extractTableName(pTableMetaInfo->name, tableName);
-
-    if (strncasecmp(tableName, pTableToken->z, pTableToken->n) == 0 && strlen(tableName) == pTableToken->n) {
+    char* name = pTableMetaInfo->aliasName;
+    if (strncasecmp(name, pTableToken->z, pTableToken->n) == 0 && strlen(name) == pTableToken->n) {
       pIndex->tableIndex = i;
       break;
     }
@@ -3081,14 +3108,14 @@ static int32_t getJoinCondInfo(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, tSQLExpr*
 }
 
 // todo error handle / such as and /or mixed with +/-/*/
-int32_t buildArithmeticExprString(tSQLExpr* pExpr, char** exprString) {
+int32_t doArithmeticExprToString(tSQLExpr* pExpr, char** exprString) {
   tSQLExpr* pLeft = pExpr->pLeft;
   tSQLExpr* pRight = pExpr->pRight;
 
   *(*exprString)++ = '(';
 
   if (pLeft->nSQLOptr >= TK_PLUS && pLeft->nSQLOptr <= TK_REM) {
-    buildArithmeticExprString(pLeft, exprString);
+    doArithmeticExprToString(pLeft, exprString);
   } else {
     int32_t ret = tSQLExprNodeToString(pLeft, exprString);
     if (ret != TSDB_CODE_SUCCESS) {
@@ -3099,7 +3126,7 @@ int32_t buildArithmeticExprString(tSQLExpr* pExpr, char** exprString) {
   optrToString(pExpr, exprString);
 
   if (pRight->nSQLOptr >= TK_PLUS && pRight->nSQLOptr <= TK_REM) {
-    buildArithmeticExprString(pRight, exprString);
+    doArithmeticExprToString(pRight, exprString);
   } else {
     int32_t ret = tSQLExprNodeToString(pRight, exprString);
     if (ret != TSDB_CODE_SUCCESS) {
@@ -3112,6 +3139,19 @@ int32_t buildArithmeticExprString(tSQLExpr* pExpr, char** exprString) {
   return TSDB_CODE_SUCCESS;
 }
 
+static int32_t arithmeticExprToString(tSQLExpr* pExpr, char** str) {
+  char* start = *str;
+
+  int32_t code = doArithmeticExprToString(pExpr, str);
+  if (code == TSDB_CODE_SUCCESS) { // remove out the parenthesis
+    int32_t len = strlen(start);
+    memmove(start, start + 1, len - 2);
+    start[len - 2] = 0;
+  }
+
+  return code;
+}
+
 static int32_t validateSQLExpr(SSqlCmd* pCmd, tSQLExpr* pExpr, SQueryInfo* pQueryInfo, SColumnList* pList, int32_t* type) {
   if (pExpr->nSQLOptr == TK_ID) {
     if (*type == NON_ARITHMEIC_EXPR) {
@@ -3615,7 +3655,7 @@ static int32_t setTableCondForSTableQuery(SSqlCmd* pCmd, SQueryInfo* pQueryInfo,
   SStringBuilder sb1; memset(&sb1, 0, sizeof(sb1));
   taosStringBuilderAppendStringLen(&sb1, QUERY_COND_REL_PREFIX_IN, QUERY_COND_REL_PREFIX_IN_LEN);
 
-  char db[TSDB_TABLE_ID_LEN] = {0};
+  char db[TSDB_TABLE_FNAME_LEN] = {0};
 
   // remove the duplicated input table names
   int32_t num = 0;
@@ -3640,7 +3680,7 @@ static int32_t setTableCondForSTableQuery(SSqlCmd* pCmd, SQueryInfo* pQueryInfo,
       taosStringBuilderAppendStringLen(&sb1, TBNAME_LIST_SEP, 1);
     }
 
-    char      idBuf[TSDB_TABLE_ID_LEN] = {0};
+    char      idBuf[TSDB_TABLE_FNAME_LEN] = {0};
     int32_t   xlen = (int32_t)strlen(segments[i]);
     SSQLToken t = {.z = segments[i], .n = xlen, .type = TK_STRING};
 
@@ -4345,7 +4385,8 @@ int32_t setAlterTableInfo(SSqlObj* pSql, struct SSqlInfo* pInfo) {
   const char* msg16 = "only support one column";
   const char* msg17 = "invalid column name";
   const char* msg18 = "primary timestamp column cannot be dropped";
-  
+  const char* msg19 = "invalid new tag name";
+
   SSqlCmd*        pCmd = &pSql->cmd;
   SAlterTableSQL* pAlterSQL = pInfo->pAlterInfo;
   SQueryInfo*     pQueryInfo = tscGetQueryInfoDetail(pCmd, 0);
@@ -4446,12 +4487,12 @@ int32_t setAlterTableInfo(SSqlObj* pSql, struct SSqlInfo* pInfo) {
 
     SSQLToken srcToken = {.z = pSrcItem->pVar.pz, .n = pSrcItem->pVar.nLen, .type = TK_STRING};
     if (getColumnIndexByName(pCmd, &srcToken, pQueryInfo, &srcIndex) != TSDB_CODE_SUCCESS) {
-      return TSDB_CODE_TSC_INVALID_SQL;
+      return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg17);
     }
 
     SSQLToken destToken = {.z = pDstItem->pVar.pz, .n = pDstItem->pVar.nLen, .type = TK_STRING};
     if (getColumnIndexByName(pCmd, &destToken, pQueryInfo, &destIndex) == TSDB_CODE_SUCCESS) {
-      return TSDB_CODE_TSC_INVALID_SQL;
+      return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg19);
     }
 
     char name[TSDB_COL_NAME_LEN] = {0};
@@ -5872,15 +5913,16 @@ int32_t doCheckForStream(SSqlObj* pSql, SSqlInfo* pInfo) {
 int32_t doCheckForQuery(SSqlObj* pSql, SQuerySQL* pQuerySql, int32_t index) {
   assert(pQuerySql != NULL && (pQuerySql->from == NULL || pQuerySql->from->nExpr > 0));
 
-  const char* msg0 = "invalid table name";
-  const char* msg1 = "table name too long";
-  const char* msg2 = "point interpolation query needs timestamp";
-  const char* msg5 = "fill only available for interval query";
-  const char* msg6 = "start(end) time of query range required or time range too large";
-  const char* msg7 = "illegal number of tables in from clause";
-  const char* msg8 = "too many columns in selection clause";
-  const char* msg9 = "TWA query requires both the start and end time";
-  const char* msg10= "too many tables in from clause";
+  const char* msg0  = "invalid table name";
+  const char* msg1  = "table name too long";
+  const char* msg2  = "point interpolation query needs timestamp";
+  const char* msg5  = "fill only available for interval query";
+  const char* msg6  = "start(end) time of query range required or time range too large";
+  const char* msg7  = "illegal number of tables in from clause";
+  const char* msg8  = "too many columns in selection clause";
+  const char* msg9  = "TWA query requires both the start and end time";
+  const char* msg10 = "too many tables in from clause";
+  const char* msg11 = "invalid table alias name";
 
   int32_t code = TSDB_CODE_SUCCESS;
 
@@ -5912,18 +5954,18 @@ int32_t doCheckForQuery(SSqlObj* pSql, SQuerySQL* pQuerySql, int32_t index) {
     return doLocalQueryProcess(pCmd, pQueryInfo, pQuerySql);
   }
 
-  if (pQuerySql->from->nExpr > TSDB_MAX_JOIN_TABLE_NUM) {
+  if (pQuerySql->from->nExpr > TSDB_MAX_JOIN_TABLE_NUM * 2) {
     return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg7);
   }
 
   pQueryInfo->command = TSDB_SQL_SELECT;
 
-  if (pQuerySql->from->nExpr > 2) {
+  if (pQuerySql->from->nExpr > 4) {
     return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg10);
   }
 
   // set all query tables, which are maybe more than one.
-  for (int32_t i = 0; i < pQuerySql->from->nExpr; ++i) {
+  for (int32_t i = 0; i < pQuerySql->from->nExpr; ) {
     tVariant* pTableItem = &pQuerySql->from->a[i].pVar;
 
     if (pTableItem->nType != TSDB_DATA_TYPE_BINARY) {
@@ -5937,24 +5979,34 @@ int32_t doCheckForQuery(SSqlObj* pSql, SQuerySQL* pQuerySql, int32_t index) {
       return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg0);
     }
 
-    if (pQueryInfo->numOfTables <= i) {  // more than one table
+    if (pQueryInfo->numOfTables <= i/2) {  // more than one table
       tscAddEmptyMetaInfo(pQueryInfo);
     }
 
-    STableMetaInfo* pMeterInfo1 = tscGetMetaInfo(pQueryInfo, i);
+    STableMetaInfo* pTableMetaInfo1 = tscGetMetaInfo(pQueryInfo, i/2);
 
     SSQLToken t = {.type = TSDB_DATA_TYPE_BINARY, .n = pTableItem->nLen, .z = pTableItem->pz};
-    if (tscSetTableFullName(pMeterInfo1, &t, pSql) != TSDB_CODE_SUCCESS) {
+    if (tscSetTableFullName(pTableMetaInfo1, &t, pSql) != TSDB_CODE_SUCCESS) {
       return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg1);
     }
 
-    code = tscGetTableMeta(pSql, pMeterInfo1);
+    tVariant* pTableItem1 = &pQuerySql->from->a[i + 1].pVar;
+    SSQLToken aliasName = {.z = pTableItem1->pz, .n = pTableItem1->nLen, .type = TK_STRING};
+    if (tscValidateName(&aliasName) != TSDB_CODE_SUCCESS) {
+      return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg11);
+    }
+
+    tstrncpy(pTableMetaInfo1->aliasName, pTableItem1->pz, sizeof(pTableMetaInfo1->aliasName));
+
+    code = tscGetTableMeta(pSql, pTableMetaInfo1);
     if (code != TSDB_CODE_SUCCESS) {
       return code;
     }
+
+    i += 2;
   }
 
-  assert(pQueryInfo->numOfTables == pQuerySql->from->nExpr);
+  assert(pQueryInfo->numOfTables == pQuerySql->from->nExpr / 2);
   bool isSTable = false;
   
   if (UTIL_TABLE_IS_SUPER_TABLE(pTableMetaInfo)) {
@@ -6122,12 +6174,14 @@ int32_t exprTreeFromSqlExpr(SSqlCmd* pCmd, tExprNode **pExpr, const tSQLExpr* pS
       if (ret != TSDB_CODE_SUCCESS) {
         return ret;
       }
-  
+
+      STableMeta* pTableMeta = tscGetMetaInfo(pQueryInfo, 0)->pTableMeta;
+      int32_t numOfColumns = tscGetNumOfColumns(pTableMeta);
+
       *pExpr = calloc(1, sizeof(tExprNode));
       (*pExpr)->nodeType = TSQL_NODE_COL;
       (*pExpr)->pSchema = calloc(1, sizeof(SSchema));
-      
-      STableMeta* pTableMeta = tscGetMetaInfo(pQueryInfo, 0)->pTableMeta;
+
       SSchema* pSchema = tscGetTableColumnSchema(pTableMeta, index.columnIndex);
       *(*pExpr)->pSchema = *pSchema;
   
@@ -6136,7 +6190,8 @@ int32_t exprTreeFromSqlExpr(SSqlCmd* pCmd, tExprNode **pExpr, const tSQLExpr* pS
         tstrncpy(colIndex.name, pSchema->name, sizeof(colIndex.name));
         colIndex.colId = pSchema->colId;
         colIndex.colIndex = index.columnIndex;
-        
+        colIndex.flag = (index.columnIndex >= numOfColumns)? 1:0;
+
         taosArrayPush(pCols, &colIndex);
       }
       
diff --git a/src/client/src/tscServer.c b/src/client/src/tscServer.c
index 3390710472..8d86f046ef 100644
--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@@ -45,19 +45,27 @@ void tscSaveSubscriptionProgress(void* sub);
 static int32_t minMsgSize() { return tsRpcHeadSize + 100; }
 
 static void tscSetDnodeEpSet(SSqlObj* pSql, SCMVgroupInfo* pVgroupInfo) {
+  assert(pSql != NULL && pVgroupInfo != NULL && pVgroupInfo->numOfEps > 0);
+
   SRpcEpSet* pEpSet = &pSql->epSet;
-  pEpSet->inUse    = 0;
-  if (pVgroupInfo == NULL) {
-    pEpSet->numOfEps = 0;
-    return;
-  }
+  pEpSet->inUse = 0;
+
+  // apply the FQDN string length check here
+  bool hasFqdn = false;
 
   pEpSet->numOfEps = pVgroupInfo->numOfEps;
   for(int32_t i = 0; i < pVgroupInfo->numOfEps; ++i) {
     strcpy(pEpSet->fqdn[i], pVgroupInfo->epAddr[i].fqdn);
     pEpSet->port[i] = pVgroupInfo->epAddr[i].port;
+
+    if (!hasFqdn) {
+      hasFqdn = (strlen(pEpSet->fqdn[i]) > 0);
+    }
   }
+
+  assert(hasFqdn);
 }
+
 static void tscDumpMgmtEpSet(SRpcEpSet *epSet) {
   taosCorBeginRead(&tscMgmtEpSet.version);
   *epSet = tscMgmtEpSet.epSet;
@@ -127,21 +135,6 @@ void tscPrintMgmtEp() {
   }
 }
 
-/*
- * For each management node, try twice at least in case of poor network situation.
- * If the client start to connect to a non-management node from the client, and the first retry may fail due to
- * the poor network quality. And then, the second retry get the response with redirection command.
- * The retry will not be executed since only *two* retry is allowed in case of single management node in the cluster.
- * Therefore, we need to multiply the retry times by factor of 2 to fix this problem.
- */
-UNUSED_FUNC
-static int32_t tscGetMgmtConnMaxRetryTimes() {
-  int32_t factor = 2;
-  SRpcEpSet dump;
-  tscDumpMgmtEpSet(&dump);
-  return dump.numOfEps * factor;
-}
-
 void tscProcessHeartBeatRsp(void *param, TAOS_RES *tres, int code) {
   STscObj *pObj = (STscObj *)param;
   if (pObj == NULL) return;
@@ -424,21 +417,18 @@ int doProcessSql(SSqlObj *pSql) {
 }
 
 int tscProcessSql(SSqlObj *pSql) {
-  char *   name = NULL;
+  char    *name = NULL;
   SSqlCmd *pCmd = &pSql->cmd;
   
-  SQueryInfo *    pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);
+  SQueryInfo     *pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);
   STableMetaInfo *pTableMetaInfo = NULL;
   uint32_t        type = 0;
 
   if (pQueryInfo != NULL) {
     pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
-    if (pTableMetaInfo != NULL) {
-      name = pTableMetaInfo->name;
-    }
-
+    name = (pTableMetaInfo != NULL)? pTableMetaInfo->name:NULL;
     type = pQueryInfo->type;
-  
+
     // while numOfTables equals to 0, it must be Heartbeat
     assert((pQueryInfo->numOfTables == 0 && pQueryInfo->command == TSDB_SQL_HB) || pQueryInfo->numOfTables > 0);
   }
@@ -450,7 +440,6 @@ int tscProcessSql(SSqlObj *pSql) {
       return pSql->res.code;
     }
   } else if (pCmd->command < TSDB_SQL_LOCAL) {
-
     //pSql->epSet = tscMgmtEpSet;
   } else {  // local handler
     return (*tscProcessMsgRsp[pCmd->command])(pSql);
@@ -597,11 +586,11 @@ static char *doSerializeTableInfo(SQueryTableMsg* pQueryMsg, SSqlObj *pSql, char
     } else {
       pVgroupInfo = &pTableMeta->vgroupInfo;
     }
-    tscSetDnodeEpSet(pSql, pVgroupInfo);
 
-    if (pVgroupInfo != NULL) {
-      pQueryMsg->head.vgId = htonl(pVgroupInfo->vgId);
-    } 
+    assert(pVgroupInfo != NULL);
+
+    tscSetDnodeEpSet(pSql, pVgroupInfo);
+    pQueryMsg->head.vgId = htonl(pVgroupInfo->vgId);
 
     STableIdInfo *pTableIdInfo = (STableIdInfo *)pMsg;
     pTableIdInfo->tid = htonl(pTableMeta->id.tid);
@@ -1460,7 +1449,7 @@ int tscProcessRetrieveLocalMergeRsp(SSqlObj *pSql) {
   SQueryInfo *pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);
 
   if (pRes->code == TSDB_CODE_SUCCESS && pRes->numOfRows > 0) {
-    tscSetResultPointer(pQueryInfo, pRes);
+    tscCreateResPointerInfo(pRes, pQueryInfo);
   }
 
   pRes->row = 0;
@@ -1562,7 +1551,7 @@ int tscBuildMultiMeterMetaMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
 
   // fill head info
   SMgmtHead *pMgmt = (SMgmtHead *)(pCmd->payload + tsRpcHeadSize);
-  memset(pMgmt->db, 0, TSDB_TABLE_ID_LEN);  // server don't need the db
+  memset(pMgmt->db, 0, TSDB_TABLE_FNAME_LEN);  // server don't need the db
 
   SCMMultiTableInfoMsg *pInfoMsg = (SCMMultiTableInfoMsg *)(pCmd->payload + tsRpcHeadSize + sizeof(SMgmtHead));
   pInfoMsg->numOfTables = htonl((int32_t)pCmd->count);
@@ -1603,7 +1592,7 @@ int tscBuildMultiMeterMetaMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
 ////    tagLen += strlen(pQueryInfo->tagCond.tbnameCond.cond) * TSDB_NCHAR_SIZE;
 ////  }
 ////
-////  int32_t joinCondLen = (TSDB_TABLE_ID_LEN + sizeof(int16_t)) * 2;
+////  int32_t joinCondLen = (TSDB_TABLE_FNAME_LEN + sizeof(int16_t)) * 2;
 ////  int32_t elemSize = sizeof(SSuperTableMetaElemMsg) * pQueryInfo->numOfTables;
 ////
 ////  int32_t colSize = pQueryInfo->groupbyExpr.numOfGroupCols*sizeof(SColIndex);
@@ -1884,11 +1873,10 @@ int tscProcessSTableVgroupRsp(SSqlObj *pSql) {
 
       for (int32_t k = 0; k < pVgroups->numOfEps; ++k) {
         pVgroups->epAddr[k].port = htons(pVgroups->epAddr[k].port);
-
       }
-
-      pMsg += size;
     }
+
+    pMsg += size;
   }
   
   return pSql->res.code;
@@ -1966,7 +1954,7 @@ int tscProcessShowRsp(SSqlObj *pSql) {
 }
 
 int tscProcessConnectRsp(SSqlObj *pSql) {
-  char temp[TSDB_TABLE_ID_LEN * 2];
+  char temp[TSDB_TABLE_FNAME_LEN * 2];
   STscObj *pObj = pSql->pTscObj;
   SSqlRes *pRes = &pSql->res;
 
@@ -2114,21 +2102,6 @@ int tscProcessRetrieveRspFromNode(SSqlObj *pSql) {
   return 0;
 }
 
-int tscProcessRetrieveRspFromLocal(SSqlObj *pSql) {
-  SSqlRes *   pRes = &pSql->res;
-  SSqlCmd *   pCmd = &pSql->cmd;
-  SQueryInfo *pQueryInfo = tscGetQueryInfoDetail(pCmd, 0);
-
-  SRetrieveTableRsp *pRetrieve = (SRetrieveTableRsp *)pRes->pRsp;
-
-  pRes->numOfRows = htonl(pRetrieve->numOfRows);
-  pRes->data = pRetrieve->data;
-
-  tscSetResultPointer(pQueryInfo, pRes);
-  pRes->row = 0;
-  return 0;
-}
-
 void tscTableMetaCallBack(void *param, TAOS_RES *res, int code);
 
 static int32_t getTableMetaFromMgmt(SSqlObj *pSql, STableMetaInfo *pTableMetaInfo) {
diff --git a/src/client/src/tscSql.c b/src/client/src/tscSql.c
index 3e5280401f..6c7503ea4c 100644
--- a/src/client/src/tscSql.c
+++ b/src/client/src/tscSql.c
@@ -233,35 +233,6 @@ static void waitForRetrieveRsp(void *param, TAOS_RES *tres, int numOfRows) {
   sem_post(&pSql->rspSem);
 }
 
-TAOS_RES* taos_query(TAOS *taos, const char *sqlstr) {
-  STscObj *pObj = (STscObj *)taos;
-  if (pObj == NULL || pObj->signature != pObj) {
-    terrno = TSDB_CODE_TSC_DISCONNECTED;
-    return NULL;
-  }
-  
-  int32_t sqlLen = (int32_t)strlen(sqlstr);
-  if (sqlLen > tsMaxSQLStringLen) {
-    tscError("sql string exceeds max length:%d", tsMaxSQLStringLen);
-    terrno = TSDB_CODE_TSC_INVALID_SQL;
-    return NULL;
-  }
-  
-  taosNotePrintTsc(sqlstr);
-  
-  SSqlObj* pSql = calloc(1, sizeof(SSqlObj));
-  if (pSql == NULL) {
-    tscError("failed to malloc sqlObj");
-    terrno = TSDB_CODE_TSC_OUT_OF_MEMORY;
-    return NULL;
-  }
-  
-  doAsyncQuery(pObj, pSql, waitForQueryRsp, taos, sqlstr, sqlLen);
-
-  // wait for the callback function to post the semaphore
-  tsem_wait(&pSql->rspSem);
-  return pSql;
-}
 TAOS_RES* taos_query_c(TAOS *taos, const char *sqlstr, uint32_t sqlLen) {
   STscObj *pObj = (STscObj *)taos;
   if (pObj == NULL || pObj->signature != pObj) {
@@ -274,7 +245,9 @@ TAOS_RES* taos_query_c(TAOS *taos, const char *sqlstr, uint32_t sqlLen) {
     terrno = TSDB_CODE_TSC_INVALID_SQL;
     return NULL;
   }
-  
+
+  taosNotePrintTsc(sqlstr);
+
   SSqlObj* pSql = calloc(1, sizeof(SSqlObj));
   if (pSql == NULL) {
     tscError("failed to malloc sqlObj");
@@ -287,6 +260,11 @@ TAOS_RES* taos_query_c(TAOS *taos, const char *sqlstr, uint32_t sqlLen) {
   tsem_wait(&pSql->rspSem);
   return pSql; 
 }
+
+TAOS_RES* taos_query(TAOS *taos, const char *sqlstr) {
+  return taos_query_c(taos, sqlstr, strlen(sqlstr));
+}
+
 int taos_result_precision(TAOS_RES *res) {
   SSqlObj *pSql = (SSqlObj *)res;
   if (pSql == NULL || pSql->signature != pSql) return 0;
@@ -422,7 +400,10 @@ TAOS_ROW taos_fetch_row(TAOS_RES *res) {
       pCmd->command == TSDB_SQL_INSERT) {
     return NULL;
   }
-  
+
+  // set the sql object owner
+  tscSetSqlOwner(pSql);
+
   // current data set are exhausted, fetch more data from node
   if (pRes->row >= pRes->numOfRows && (pRes->completed != true || hasMoreVnodesToTry(pSql) || hasMoreClauseToTry(pSql)) &&
       (pCmd->command == TSDB_SQL_RETRIEVE ||
@@ -441,7 +422,10 @@ TAOS_ROW taos_fetch_row(TAOS_RES *res) {
     sem_wait(&pSql->rspSem);
   }
 
-  return doSetResultRowData(pSql, true);
+  void* data = doSetResultRowData(pSql, true);
+
+  tscClearSqlOwner(pSql);
+  return data;
 }
 
 int taos_fetch_block(TAOS_RES *res, TAOS_ROW *rows) {
@@ -509,7 +493,7 @@ int taos_select_db(TAOS *taos, const char *db) {
 }
 
 // send free message to vnode to free qhandle and corresponding resources in vnode
-static bool tscFreeQhandleInVnode(SSqlObj* pSql) {
+static bool tscKillQueryInVnode(SSqlObj* pSql) {
   SSqlCmd* pCmd = &pSql->cmd;
   SSqlRes* pRes = &pSql->res;
 
@@ -557,16 +541,14 @@ void taos_free_result(TAOS_RES *res) {
   }
 
   pQueryInfo->type = TSDB_QUERY_TYPE_FREE_RESOURCE;
-  if (!tscFreeQhandleInVnode(pSql)) {
+  if (!tscKillQueryInVnode(pSql)) {
     tscFreeSqlObj(pSql);
     tscDebug("%p sqlObj is freed by app", pSql);
   }
 }
 
-// todo should not be used in async query
 int taos_errno(TAOS_RES *tres) {
   SSqlObj *pSql = (SSqlObj *) tres;
-
   if (pSql == NULL || pSql->signature != pSql) {
     return terrno;
   }
@@ -812,7 +794,7 @@ static int tscParseTblNameList(SSqlObj *pSql, const char *tblNameList, int32_t t
   }
 
   char *nextStr;
-  char  tblName[TSDB_TABLE_ID_LEN];
+  char  tblName[TSDB_TABLE_FNAME_LEN];
   int   payloadLen = 0;
   char *pMsg = pCmd->payload;
   while (1) {
diff --git a/src/client/src/tscSubquery.c b/src/client/src/tscSubquery.c
index 8a596d8893..69a6d5db5b 100644
--- a/src/client/src/tscSubquery.c
+++ b/src/client/src/tscSubquery.c
@@ -1026,9 +1026,11 @@ void tscSetupOutputColumnIndex(SSqlObj* pSql) {
   }
 
   SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);
-  pRes->pColumnIndex = calloc(1, sizeof(SColumnIndex) * pQueryInfo->fieldsInfo.numOfOutput);
 
-  for (int32_t i = 0; i < pQueryInfo->fieldsInfo.numOfOutput; ++i) {
+  int32_t numOfExprs = tscSqlExprNumOfExprs(pQueryInfo);
+  pRes->pColumnIndex = calloc(1, sizeof(SColumnIndex) * numOfExprs);
+
+  for (int32_t i = 0; i < numOfExprs; ++i) {
     SSqlExpr* pExpr = tscSqlExprGet(pQueryInfo, i);
 
     int32_t tableIndexOfSub = -1;
@@ -1045,8 +1047,8 @@ void tscSetupOutputColumnIndex(SSqlObj* pSql) {
     SSqlCmd* pSubCmd = &pSql->pSubs[tableIndexOfSub]->cmd;
     SQueryInfo* pSubQueryInfo = tscGetQueryInfoDetail(pSubCmd, 0);
     
-    size_t numOfExprs = taosArrayGetSize(pSubQueryInfo->exprList);
-    for (int32_t k = 0; k < numOfExprs; ++k) {
+    size_t numOfSubExpr = taosArrayGetSize(pSubQueryInfo->exprList);
+    for (int32_t k = 0; k < numOfSubExpr; ++k) {
       SSqlExpr* pSubExpr = tscSqlExprGet(pSubQueryInfo, k);
       if (pExpr->functionId == pSubExpr->functionId && pExpr->colInfo.colId == pSubExpr->colInfo.colId) {
         pRes->pColumnIndex[i] = (SColumnIndex){.tableIndex = tableIndexOfSub, .columnIndex = k};
@@ -1054,6 +1056,10 @@ void tscSetupOutputColumnIndex(SSqlObj* pSql) {
       }
     }
   }
+
+  // restore the offset value for super table query in case of final result.
+  tscRestoreSQLFuncForSTableQuery(pQueryInfo);
+  tscFieldInfoUpdateOffset(pQueryInfo);
 }
 
 void tscJoinQueryCallback(void* param, TAOS_RES* tres, int code) {
@@ -1079,7 +1085,7 @@ void tscJoinQueryCallback(void* param, TAOS_RES* tres, int code) {
   if (taos_errno(pSql) != TSDB_CODE_SUCCESS) {
     assert(taos_errno(pSql) == code);
 
-    tscError("%p abort query, code:%d, global code:%d", pSql, code, pParentSql->res.code);
+    tscError("%p abort query, code:%s, global code:%s", pSql, tstrerror(code), tstrerror(pParentSql->res.code));
     pParentSql->res.code = code;
 
     quitAllSubquery(pParentSql, pSupporter);
@@ -2052,9 +2058,7 @@ void tscBuildResFromSubqueries(SSqlObj *pSql) {
   }
 
   while (1) {
-    if (pRes->row < pRes->numOfRows) {
-      assert(0);
-    }
+    assert (pRes->row >= pRes->numOfRows);
 
     doBuildResFromSubqueries(pSql);
     sem_post(&pSql->rspSem);
diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index 1b6d18be0c..fcc752983c 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -644,7 +644,7 @@ int32_t tscMergeTableDataBlocks(SSqlObj* pSql, SArray* pTableDataBlockList) {
   STableDataBlocks* pOneTableBlock = taosArrayGetP(pTableDataBlockList, 0);
   int32_t expandSize = getRowExpandSize(pOneTableBlock->pTableMeta);
 
-  void* pVnodeDataBlockHashList = taosHashInit(128, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BIGINT), false);
+  void* pVnodeDataBlockHashList = taosHashInit(128, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BIGINT), true, false);
   SArray* pVnodeDataBlockList = taosArrayInit(8, POINTER_BYTES);
 
   size_t total = taosArrayGetSize(pTableDataBlockList);
@@ -858,12 +858,13 @@ void tscFieldInfoCopy(SFieldInfo* dst, const SFieldInfo* src) {
 }
 
 TAOS_FIELD* tscFieldInfoGetField(SFieldInfo* pFieldInfo, int32_t index) {
+  assert(index < pFieldInfo->numOfOutput);
   return TARRAY_GET_ELEM(pFieldInfo->pFields, index);
 }
 
 int16_t tscFieldInfoGetOffset(SQueryInfo* pQueryInfo, int32_t index) {
   SFieldSupInfo* pInfo = tscFieldInfoGetSupp(&pQueryInfo->fieldsInfo, index);
-  assert(pInfo != NULL);
+  assert(pInfo != NULL && pInfo->pSqlExpr != NULL);
 
   return pInfo->pSqlExpr->offset;
 }
@@ -1680,6 +1681,77 @@ SSqlObj* createSimpleSubObj(SSqlObj* pSql, void (*fp)(), void* param, int32_t cm
   return pNew;
 }
 
+// current sql function is not direct output result, so create a dummy output field
+static void doSetNewFieldInfo(SQueryInfo* pNewQueryInfo, SSqlExpr* pExpr) {
+  TAOS_FIELD f = {.type = pExpr->resType, .bytes = pExpr->resBytes};
+  tstrncpy(f.name, pExpr->aliasName, sizeof(f.name));
+
+  SFieldSupInfo* pInfo1 = tscFieldInfoAppend(&pNewQueryInfo->fieldsInfo, &f);
+
+  pInfo1->pSqlExpr = pExpr;
+  pInfo1->visible = false;
+}
+
+static void doSetSqlExprAndResultFieldInfo(SQueryInfo* pQueryInfo, SQueryInfo* pNewQueryInfo, int64_t uid) {
+  int32_t numOfOutput = tscSqlExprNumOfExprs(pNewQueryInfo);
+  if (numOfOutput == 0) {
+    return;
+  }
+
+  size_t      numOfExprs = tscSqlExprNumOfExprs(pQueryInfo);
+  SFieldInfo* pFieldInfo = &pQueryInfo->fieldsInfo;
+
+  // set the field info in pNewQueryInfo object
+  for (int32_t i = 0; i < numOfExprs; ++i) {
+    SSqlExpr* pExpr = tscSqlExprGet(pQueryInfo, i);
+
+    if (pExpr->uid == uid) {
+      if (i < pFieldInfo->numOfOutput) {
+        SFieldSupInfo* pInfo = tscFieldInfoGetSupp(pFieldInfo, i);
+
+        if (pInfo->pSqlExpr != NULL) {
+          TAOS_FIELD* p = tscFieldInfoGetField(pFieldInfo, i);
+          assert(strcmp(p->name, pExpr->aliasName) == 0);
+
+          SFieldSupInfo* pInfo1 = tscFieldInfoAppend(&pNewQueryInfo->fieldsInfo, p);
+          *pInfo1 = *pInfo;
+        } else {
+          assert(pInfo->pArithExprInfo != NULL);
+          doSetNewFieldInfo(pNewQueryInfo, pExpr);
+        }
+      } else { // it is a arithmetic column, does not have actual field for sqlExpr, so build it
+        doSetNewFieldInfo(pNewQueryInfo, pExpr);
+      }
+    }
+  }
+
+  // make sure the the sqlExpr for each fields is correct
+  numOfExprs = tscSqlExprNumOfExprs(pNewQueryInfo);
+
+  // update the pSqlExpr pointer in SFieldSupInfo according the field name
+  // make sure the pSqlExpr point to the correct SqlExpr in pNewQueryInfo, not SqlExpr in pQueryInfo
+  for (int32_t f = 0; f < pNewQueryInfo->fieldsInfo.numOfOutput; ++f) {
+    TAOS_FIELD* field = tscFieldInfoGetField(&pNewQueryInfo->fieldsInfo, f);
+
+    bool matched = false;
+    for (int32_t k1 = 0; k1 < numOfExprs; ++k1) {
+      SSqlExpr* pExpr1 = tscSqlExprGet(pNewQueryInfo, k1);
+
+      if (strcmp(field->name, pExpr1->aliasName) == 0) {  // establish link according to the result field name
+        SFieldSupInfo* pInfo = tscFieldInfoGetSupp(&pNewQueryInfo->fieldsInfo, f);
+        pInfo->pSqlExpr = pExpr1;
+
+        matched = true;
+        break;
+      }
+    }
+
+    assert(matched);
+  }
+
+  tscFieldInfoUpdateOffset(pNewQueryInfo);
+}
+
 SSqlObj* createSubqueryObj(SSqlObj* pSql, int16_t tableIndex, void (*fp)(), void* param, int32_t cmd, SSqlObj* pPrevSql) {
   SSqlCmd* pCmd = &pSql->cmd;
   SSqlObj* pNew = (SSqlObj*)calloc(1, sizeof(SSqlObj));
@@ -1773,49 +1845,7 @@ SSqlObj* createSubqueryObj(SSqlObj* pSql, int16_t tableIndex, void (*fp)(), void
   uint64_t uid = pTableMetaInfo->pTableMeta->id.uid;
   tscSqlExprCopy(pNewQueryInfo->exprList, pQueryInfo->exprList, uid, true);
 
-  int32_t numOfOutput = (int32_t)tscSqlExprNumOfExprs(pNewQueryInfo);
-
-  if (numOfOutput > 0) {  // todo refactor to extract method
-    size_t numOfExprs = tscSqlExprNumOfExprs(pQueryInfo);
-    SFieldInfo* pFieldInfo = &pQueryInfo->fieldsInfo;
-    
-    for (int32_t i = 0; i < numOfExprs; ++i) {
-      SSqlExpr* pExpr = tscSqlExprGet(pQueryInfo, i);
-      
-      if (pExpr->uid == uid) {
-        TAOS_FIELD* p = tscFieldInfoGetField(pFieldInfo, i);
-        SFieldSupInfo* pInfo = tscFieldInfoGetSupp(pFieldInfo, i);
-  
-        SFieldSupInfo* pInfo1 = tscFieldInfoAppend(&pNewQueryInfo->fieldsInfo, p);
-        *pInfo1 = *pInfo;
-      }
-    }
-
-    // make sure the the sqlExpr for each fields is correct
-    // todo handle the agg arithmetic expression
-    numOfExprs = tscSqlExprNumOfExprs(pNewQueryInfo);
-
-    for(int32_t f = 0; f < pNewQueryInfo->fieldsInfo.numOfOutput; ++f) {
-      TAOS_FIELD* field = tscFieldInfoGetField(&pNewQueryInfo->fieldsInfo, f);
-      bool matched = false;
-
-      for(int32_t k1 = 0; k1 < numOfExprs; ++k1) {
-        SSqlExpr* pExpr1 = tscSqlExprGet(pNewQueryInfo, k1);
-
-        if (strcmp(field->name, pExpr1->aliasName) == 0) {  // establish link according to the result field name
-          SFieldSupInfo* pInfo = tscFieldInfoGetSupp(&pNewQueryInfo->fieldsInfo, f);
-          pInfo->pSqlExpr = pExpr1;
-
-          matched = true;
-          break;
-        }
-      }
-
-      assert(matched);
-    }
-  
-    tscFieldInfoUpdateOffset(pNewQueryInfo);
-  }
+  doSetSqlExprAndResultFieldInfo(pQueryInfo, pNewQueryInfo, uid);
 
   pNew->fp = fp;
   pNew->fetchFp = fp;
@@ -2013,6 +2043,10 @@ bool hasMoreVnodesToTry(SSqlObj* pSql) {
   }
   
   int32_t numOfVgroups = pTableMetaInfo->vgroupList->numOfVgroups;
+  if (pTableMetaInfo->pVgroupTables != NULL) {
+    numOfVgroups = taosArrayGetSize(pTableMetaInfo->pVgroupTables);
+  }
+
   return tscNonOrderedProjectionQueryOnSTable(pQueryInfo, 0) &&
          (!tscHasReachLimitation(pQueryInfo, pRes)) && (pTableMetaInfo->vgroupIndex < numOfVgroups - 1);
 }
@@ -2200,3 +2234,21 @@ int tscSetMgmtEpSetFromCfg(const char *first, const char *second) {
 
   return 0;
 }
+
+bool tscSetSqlOwner(SSqlObj* pSql) {
+  SSqlRes* pRes = &pSql->res;
+
+  // set the sql object owner
+  uint64_t threadId = taosGetPthreadId();
+  if (atomic_val_compare_exchange_64(&pSql->owner, 0, threadId) != 0) {
+    pRes->code = TSDB_CODE_QRY_IN_EXEC;
+    return false;
+  }
+
+  return true;
+}
+
+void tscClearSqlOwner(SSqlObj* pSql) {
+  assert(pSql->owner != 0);
+  atomic_store_64(&pSql->owner, 0);
+}
\ No newline at end of file
diff --git a/src/dnode/src/dnodeVRead.c b/src/dnode/src/dnodeVRead.c
index cb53bb5e60..c99cf87b21 100644
--- a/src/dnode/src/dnodeVRead.c
+++ b/src/dnode/src/dnodeVRead.c
@@ -202,8 +202,9 @@ static void *dnodeProcessReadQueue(void *param) {
       break;
     }
 
-    dDebug("%p, msg:%s will be processed in vread queue, qtype:%d", pReadMsg->rpcMsg.ahandle,
-           taosMsg[pReadMsg->rpcMsg.msgType], type);
+    dDebug("%p, msg:%s will be processed in vread queue, qtype:%d, msg:%p", pReadMsg->rpcMsg.ahandle,
+           taosMsg[pReadMsg->rpcMsg.msgType], type, pReadMsg);
+
     int32_t code = vnodeProcessRead(pVnode, pReadMsg);
 
     if (type == TAOS_QTYPE_RPC && code != TSDB_CODE_QRY_NOT_READY) {
diff --git a/src/inc/query.h b/src/inc/query.h
index ec1e458b62..0c18f85dc3 100644
--- a/src/inc/query.h
+++ b/src/inc/query.h
@@ -76,6 +76,9 @@ void* qGetResultRetrieveMsg(qinfo_t qinfo);
  */
 int32_t qKillQuery(qinfo_t qinfo);
 
+int32_t qQueryCompleted(qinfo_t qinfo);
+
+
 /**
  * destroy query info structure
  * @param qHandle
diff --git a/src/inc/taosdef.h b/src/inc/taosdef.h
index ff05c840da..aa59418347 100644
--- a/src/inc/taosdef.h
+++ b/src/inc/taosdef.h
@@ -232,7 +232,7 @@ void tsDataSwap(void *pLeft, void *pRight, int32_t type, int32_t size);
 #define TSDB_NODE_NAME_LEN        64
 #define TSDB_TABLE_NAME_LEN       193     // it is a null-terminated string
 #define TSDB_DB_NAME_LEN          33
-#define TSDB_TABLE_ID_LEN         (TSDB_ACCT_LEN + TSDB_DB_NAME_LEN + TSDB_TABLE_NAME_LEN)
+#define TSDB_TABLE_FNAME_LEN      (TSDB_ACCT_LEN + TSDB_DB_NAME_LEN + TSDB_TABLE_NAME_LEN)
 #define TSDB_COL_NAME_LEN         65
 #define TSDB_MAX_SAVED_SQL_LEN    TSDB_MAX_COLUMNS * 64
 #define TSDB_MAX_SQL_LEN          TSDB_PAYLOAD_SIZE
diff --git a/src/inc/taoserror.h b/src/inc/taoserror.h
index ece08ae173..9af4cee28a 100644
--- a/src/inc/taoserror.h
+++ b/src/inc/taoserror.h
@@ -219,6 +219,7 @@ TAOS_DEFINE_ERROR(TSDB_CODE_QRY_DUP_JOIN_KEY,             0, 0x0705, "Duplicated
 TAOS_DEFINE_ERROR(TSDB_CODE_QRY_EXCEED_TAGS_LIMIT,        0, 0x0706, "Tag conditon too many")
 TAOS_DEFINE_ERROR(TSDB_CODE_QRY_NOT_READY,                0, 0x0707, "Query not ready")
 TAOS_DEFINE_ERROR(TSDB_CODE_QRY_HAS_RSP,                  0, 0x0708, "Query should response")
+TAOS_DEFINE_ERROR(TSDB_CODE_QRY_IN_EXEC,                  0, 0x0709, "Multiple retrieval of this query")
 
 // grant
 TAOS_DEFINE_ERROR(TSDB_CODE_GRANT_EXPIRED,                0, 0x0800, "License expired")
diff --git a/src/inc/taosmsg.h b/src/inc/taosmsg.h
index 6d43568ecd..265bf47d6d 100644
--- a/src/inc/taosmsg.h
+++ b/src/inc/taosmsg.h
@@ -246,13 +246,13 @@ typedef struct {
   uint64_t uid;
   uint64_t superTableUid;
   uint64_t createdTime;
-  char     tableId[TSDB_TABLE_ID_LEN];
-  char     superTableId[TSDB_TABLE_ID_LEN];
+  char     tableId[TSDB_TABLE_FNAME_LEN];
+  char     superTableId[TSDB_TABLE_FNAME_LEN];
   char     data[];
 } SMDCreateTableMsg;
 
 typedef struct {
-  char    tableId[TSDB_TABLE_ID_LEN];
+  char    tableId[TSDB_TABLE_FNAME_LEN];
   char    db[TSDB_ACCT_LEN + TSDB_DB_NAME_LEN];
   int8_t  igExists;
   int8_t  getMeta;
@@ -265,12 +265,12 @@ typedef struct {
 } SCMCreateTableMsg;
 
 typedef struct {
-  char   tableId[TSDB_TABLE_ID_LEN];
+  char   tableId[TSDB_TABLE_FNAME_LEN];
   int8_t igNotExists;
 } SCMDropTableMsg;
 
 typedef struct {
-  char    tableId[TSDB_TABLE_ID_LEN];
+  char    tableId[TSDB_TABLE_FNAME_LEN];
   char    db[TSDB_ACCT_LEN + TSDB_DB_NAME_LEN];
   int16_t type; /* operation type   */
   int16_t numOfCols; /* number of schema */
@@ -297,7 +297,7 @@ typedef struct {
 typedef struct {
   char clientVersion[TSDB_VERSION_LEN];
   char msgVersion[TSDB_VERSION_LEN];
-  char db[TSDB_TABLE_ID_LEN];
+  char db[TSDB_TABLE_FNAME_LEN];
 } SCMConnectMsg;
 
 typedef struct {
@@ -347,14 +347,14 @@ typedef struct {
   int32_t  vgId;
   int32_t  sid;
   uint64_t uid;
-  char     tableId[TSDB_TABLE_ID_LEN];
+  char     tableId[TSDB_TABLE_FNAME_LEN];
 } SMDDropTableMsg;
 
 typedef struct {
   int32_t  contLen;
   int32_t  vgId;
   uint64_t uid;
-  char    tableId[TSDB_TABLE_ID_LEN];
+  char    tableId[TSDB_TABLE_FNAME_LEN];
 } SMDDropSTableMsg;
 
 typedef struct {
@@ -527,7 +527,7 @@ typedef struct {
 } SCMCreateDbMsg, SCMAlterDbMsg;
 
 typedef struct {
-  char    db[TSDB_TABLE_ID_LEN];
+  char    db[TSDB_TABLE_FNAME_LEN];
   uint8_t ignoreNotExists;
 } SCMDropDbMsg, SCMUseDbMsg;
 
@@ -637,7 +637,7 @@ typedef struct {
 } SMDCreateVnodeMsg, SMDAlterVnodeMsg;
 
 typedef struct {
-  char    tableId[TSDB_TABLE_ID_LEN];
+  char    tableId[TSDB_TABLE_FNAME_LEN];
   int16_t createFlag;
   char    tags[];
 } SCMTableInfoMsg;
@@ -664,7 +664,7 @@ typedef struct {
 
 typedef struct STableMetaMsg {
   int32_t       contLen;
-  char          tableId[TSDB_TABLE_ID_LEN];   // table id
+  char          tableId[TSDB_TABLE_FNAME_LEN];   // table id
   uint8_t       numOfTags;
   uint8_t       precision;
   uint8_t       tableType;
@@ -685,7 +685,7 @@ typedef struct SMultiTableMeta {
 
 typedef struct {
   int32_t dataLen;
-  char name[TSDB_TABLE_ID_LEN];
+  char name[TSDB_TABLE_FNAME_LEN];
   char data[TSDB_MAX_TAGS_LEN + TD_KV_ROW_HEAD_SIZE + sizeof(SColIdx) * TSDB_MAX_TAGS];
 } STagData;
 
@@ -771,7 +771,7 @@ typedef struct {
   uint64_t uid;
   uint64_t stime;  // stream starting time
   int32_t  status;
-  char     tableId[TSDB_TABLE_ID_LEN];
+  char     tableId[TSDB_TABLE_FNAME_LEN];
 } SMDAlterStreamMsg;
 
 typedef struct {
diff --git a/src/inc/tsdb.h b/src/inc/tsdb.h
index bab17322f0..4776d1cda7 100644
--- a/src/inc/tsdb.h
+++ b/src/inc/tsdb.h
@@ -167,9 +167,14 @@ typedef struct SDataBlockInfo {
 } SDataBlockInfo;
 
 typedef struct {
-  size_t   numOfTables;
+  void  *pTable;
+  TSKEY  lastKey;
+} STableKeyInfo;
+
+typedef struct {
+  size_t    numOfTables;
   SArray   *pGroupList;
-  SHashObj *map;         // speedup acquire the tableQueryInfo from STableId
+  SHashObj *map;         // speedup acquire the tableQueryInfo by table uid
 } STableGroupInfo;
 
 /**
@@ -177,24 +182,24 @@ typedef struct {
  *
  * @param tsdb       tsdb handle
  * @param pCond      query condition, including time window, result set order, and basic required columns for each block
- * @param tableqinfoGroupInfo  tableId list in the form of set, seperated into different groups according to group by condition
+ * @param tableInfoGroup  table object list in the form of set, grouped into different sets according to the
+ *                        group by condition
  * @param qinfo      query info handle from query processor
  * @return
  */
-TsdbQueryHandleT *tsdbQueryTables(TSDB_REPO_T *tsdb, STsdbQueryCond *pCond, STableGroupInfo *tableqinfoGroupInfo, void *qinfo);
+TsdbQueryHandleT *tsdbQueryTables(TSDB_REPO_T *tsdb, STsdbQueryCond *pCond, STableGroupInfo *tableInfoGroup, void *qinfo);
 
 /**
  * Get the last row of the given query time window for all the tables in STableGroupInfo object.
  * Note that only one data block with only row will be returned while invoking retrieve data block function for
  * all tables in this group.
  *
- * @param tsdb        tsdb handle
- * @param pCond       query condition, including time window, result set order, and basic required columns for each
- * block
- * @param tableqinfoGroupInfo   tableId list.
+ * @param tsdb   tsdb handle
+ * @param pCond  query condition, including time window, result set order, and basic required columns for each block
+ * @param tableInfo  table list.
  * @return
  */
-TsdbQueryHandleT tsdbQueryLastRow(TSDB_REPO_T *tsdb, STsdbQueryCond *pCond, STableGroupInfo *tableqinfoGroupInfo, void *qinfo);
+TsdbQueryHandleT tsdbQueryLastRow(TSDB_REPO_T *tsdb, STsdbQueryCond *pCond, STableGroupInfo *tableInfo, void *qinfo);
 
 /**
  * get the queried table object list
@@ -260,7 +265,7 @@ SArray *tsdbRetrieveDataBlock(TsdbQueryHandleT *pQueryHandle, SArray *pColumnIdL
  * @param stableid. super table sid
  * @param pTagCond. tag query condition
  */
-int32_t tsdbQuerySTableByTagCond(TSDB_REPO_T *tsdb, uint64_t uid, const char *pTagCond, size_t len,
+int32_t tsdbQuerySTableByTagCond(TSDB_REPO_T *tsdb, uint64_t uid, TSKEY key, const char *pTagCond, size_t len,
                                  int16_t tagNameRelType, const char *tbnameCond, STableGroupInfo *pGroupList,
                                  SColIndex *pColIndex, int32_t numOfCols);
 
@@ -278,7 +283,7 @@ void tsdbDestroyTableGroup(STableGroupInfo *pGroupList);
  * @param pGroupInfo  the generated result
  * @return
  */
-int32_t tsdbGetOneTableGroup(TSDB_REPO_T *tsdb, uint64_t uid, STableGroupInfo *pGroupInfo);
+int32_t tsdbGetOneTableGroup(TSDB_REPO_T *tsdb, uint64_t uid, TSKEY startKey, STableGroupInfo *pGroupInfo);
 
 /**
  *
diff --git a/src/mnode/src/mnodeDb.c b/src/mnode/src/mnodeDb.c
index 7f9be7eb54..f6249986fd 100644
--- a/src/mnode/src/mnodeDb.c
+++ b/src/mnode/src/mnodeDb.c
@@ -193,7 +193,7 @@ void mnodeDecDbRef(SDbObj *pDb) {
 }
 
 SDbObj *mnodeGetDbByTableId(char *tableId) {
-  char db[TSDB_TABLE_ID_LEN], *pos;
+  char db[TSDB_TABLE_FNAME_LEN], *pos;
  
   // tableId format should be :  acct.db.table
   pos = strstr(tableId, TS_PATH_DELIMITER);
@@ -1046,7 +1046,7 @@ static int32_t mnodeProcessDropDbMsg(SMnodeMsg *pMsg) {
   if (pMsg->pDb == NULL) pMsg->pDb = mnodeGetDb(pDrop->db);
   if (pMsg->pDb == NULL) {
     if (pDrop->ignoreNotExists) {
-      mDebug("db:%s, db is not exist, think drop success", pDrop->db);
+      mDebug("db:%s, db is not exist, treat as success", pDrop->db);
       return TSDB_CODE_SUCCESS;
     } else {
       mError("db:%s, failed to drop, invalid db", pDrop->db);
diff --git a/src/mnode/src/mnodeProfile.c b/src/mnode/src/mnodeProfile.c
index 353dd59671..85457d7a26 100644
--- a/src/mnode/src/mnodeProfile.c
+++ b/src/mnode/src/mnodeProfile.c
@@ -73,13 +73,13 @@ int32_t mnodeInitProfile() {
 
 void mnodeCleanupProfile() {
   if (tsMnodeConnCache != NULL) {
-    mInfo("conn cache is cleanup");
     taosCacheCleanup(tsMnodeConnCache);
     tsMnodeConnCache = NULL;
   }
 }
 
 SConnObj *mnodeCreateConn(char *user, uint32_t ip, uint16_t port) {
+#if 0
   int32_t connSize = taosHashGetSize(tsMnodeConnCache->pHashTable);
   if (connSize > tsMaxShellConns) {
     mError("failed to create conn for user:%s ip:%s:%u, conns:%d larger than maxShellConns:%d, ", user, taosIpStr(ip),
@@ -87,6 +87,7 @@ SConnObj *mnodeCreateConn(char *user, uint32_t ip, uint16_t port) {
     terrno = TSDB_CODE_MND_TOO_MANY_SHELL_CONNS;
     return NULL;
   }
+#endif  
 
   int32_t connId = atomic_add_fetch_32(&tsConnIndex, 1);
   if (connId == 0) atomic_add_fetch_32(&tsConnIndex, 1);
@@ -100,7 +101,7 @@ SConnObj *mnodeCreateConn(char *user, uint32_t ip, uint16_t port) {
   tstrncpy(connObj.user, user, sizeof(connObj.user));
   
   SConnObj *pConn = taosCachePut(tsMnodeConnCache, &connId, sizeof(int32_t), &connObj, sizeof(connObj), CONN_KEEP_TIME);
-  
+
   mDebug("connId:%d, is created, user:%s ip:%s:%u", connId, user, taosIpStr(ip), port);
   return pConn;
 }
@@ -112,7 +113,7 @@ void mnodeReleaseConn(SConnObj *pConn) {
 
 SConnObj *mnodeAccquireConn(int32_t connId, char *user, uint32_t ip, uint16_t port) {
   uint64_t expireTime = CONN_KEEP_TIME * 1000 + (uint64_t)taosGetTimestampMs();
-  SConnObj *pConn = taosCacheUpdateExpireTimeByName(tsMnodeConnCache, &connId, sizeof(int32_t), expireTime);
+  SConnObj *pConn = taosCacheAcquireByKey(tsMnodeConnCache, &connId, sizeof(int32_t));
   if (pConn == NULL) {
     mDebug("connId:%d, is already destroyed, user:%s ip:%s:%u", connId, user, taosIpStr(ip), port);
     return NULL;
diff --git a/src/mnode/src/mnodeSdb.c b/src/mnode/src/mnodeSdb.c
index efca748e9f..3651aa8aad 100644
--- a/src/mnode/src/mnodeSdb.c
+++ b/src/mnode/src/mnodeSdb.c
@@ -874,7 +874,7 @@ void *sdbOpenTable(SSdbTableDesc *pDesc) {
   if (pTable->keyType == SDB_KEY_STRING || pTable->keyType == SDB_KEY_VAR_STRING) {
     hashFp = taosGetDefaultHashFunction(TSDB_DATA_TYPE_BINARY);
   }
-  pTable->iHandle = taosHashInit(pTable->hashSessions, hashFp, true);
+  pTable->iHandle = taosHashInit(pTable->hashSessions, hashFp, true, true);
 
   tsSdbObj.numOfTables++;
   tsSdbObj.tableList[pTable->tableId] = pTable;
diff --git a/src/mnode/src/mnodeShow.c b/src/mnode/src/mnodeShow.c
index 995bfbe840..9983c111f6 100644
--- a/src/mnode/src/mnodeShow.c
+++ b/src/mnode/src/mnodeShow.c
@@ -302,7 +302,7 @@ static int32_t mnodeProcessConnectMsg(SMnodeMsg *pMsg) {
   SAcctObj *pAcct = pUser->pAcct;
 
   if (pConnectMsg->db[0]) {
-    char dbName[TSDB_TABLE_ID_LEN * 3] = {0};
+    char dbName[TSDB_TABLE_FNAME_LEN * 3] = {0};
     sprintf(dbName, "%x%s%s", pAcct->acctId, TS_PATH_DELIMITER, pConnectMsg->db);
     SDbObj *pDb = mnodeGetDb(dbName);
     if (pDb == NULL) {
diff --git a/src/mnode/src/mnodeTable.c b/src/mnode/src/mnodeTable.c
index 7b928fe885..dbc1bffa5c 100644
--- a/src/mnode/src/mnodeTable.c
+++ b/src/mnode/src/mnodeTable.c
@@ -215,7 +215,7 @@ static int32_t mnodeChildTableActionEncode(SSdbOper *pOper) {
   assert(pTable != NULL && pOper->rowData != NULL);
 
   int32_t len = strlen(pTable->info.tableId);
-  if (len >= TSDB_TABLE_ID_LEN) return TSDB_CODE_MND_INVALID_TABLE_ID;
+  if (len >= TSDB_TABLE_FNAME_LEN) return TSDB_CODE_MND_INVALID_TABLE_ID;
 
   memcpy(pOper->rowData, pTable->info.tableId, len);
   memset(pOper->rowData + len, 0, 1);
@@ -246,7 +246,7 @@ static int32_t mnodeChildTableActionDecode(SSdbOper *pOper) {
   if (pTable == NULL) return TSDB_CODE_MND_OUT_OF_MEMORY;
 
   int32_t len = strlen(pOper->rowData);
-  if (len >= TSDB_TABLE_ID_LEN) {
+  if (len >= TSDB_TABLE_FNAME_LEN) {
     free(pTable);
     return TSDB_CODE_MND_INVALID_TABLE_ID;
   }
@@ -348,7 +348,7 @@ static int32_t mnodeInitChildTables() {
     .tableId      = SDB_TABLE_CTABLE,
     .tableName    = "ctables",
     .hashSessions = TSDB_DEFAULT_CTABLES_HASH_SIZE,
-    .maxRowSize   = sizeof(SChildTableObj) + sizeof(SSchema) * (TSDB_MAX_TAGS + TSDB_MAX_COLUMNS + 16) + TSDB_TABLE_ID_LEN + TSDB_CQ_SQL_SIZE,
+    .maxRowSize   = sizeof(SChildTableObj) + sizeof(SSchema) * (TSDB_MAX_TAGS + TSDB_MAX_COLUMNS + 16) + TSDB_TABLE_FNAME_LEN + TSDB_CQ_SQL_SIZE,
     .refCountPos  = (int8_t *)(&tObj.refCount) - (int8_t *)&tObj,
     .keyType      = SDB_KEY_VAR_STRING,
     .insertFp     = mnodeChildTableActionInsert,
@@ -387,7 +387,7 @@ static void mnodeAddTableIntoStable(SSuperTableObj *pStable, SChildTableObj *pCt
   atomic_add_fetch_32(&pStable->numOfTables, 1);
 
   if (pStable->vgHash == NULL) {
-    pStable->vgHash = taosHashInit(64, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), false);
+    pStable->vgHash = taosHashInit(64, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), true, false);
   }
 
   if (pStable->vgHash != NULL) {
@@ -479,7 +479,7 @@ static int32_t mnodeSuperTableActionEncode(SSdbOper *pOper) {
   assert(pOper->pObj != NULL && pOper->rowData != NULL);
 
   int32_t len = strlen(pStable->info.tableId);
-  if (len >= TSDB_TABLE_ID_LEN) len = TSDB_CODE_MND_INVALID_TABLE_ID;
+  if (len >= TSDB_TABLE_FNAME_LEN) len = TSDB_CODE_MND_INVALID_TABLE_ID;
 
   memcpy(pOper->rowData, pStable->info.tableId, len);
   memset(pOper->rowData + len, 0, 1);
@@ -503,7 +503,7 @@ static int32_t mnodeSuperTableActionDecode(SSdbOper *pOper) {
   if (pStable == NULL) return TSDB_CODE_MND_OUT_OF_MEMORY;
 
   int32_t len = strlen(pOper->rowData);
-  if (len >= TSDB_TABLE_ID_LEN){
+  if (len >= TSDB_TABLE_FNAME_LEN){
     free(pStable);
     return TSDB_CODE_MND_INVALID_TABLE_ID;
   }
@@ -539,7 +539,7 @@ static int32_t mnodeInitSuperTables() {
     .tableId      = SDB_TABLE_STABLE,
     .tableName    = "stables",
     .hashSessions = TSDB_DEFAULT_STABLES_HASH_SIZE,
-    .maxRowSize   = sizeof(SSuperTableObj) + sizeof(SSchema) * (TSDB_MAX_TAGS + TSDB_MAX_COLUMNS + 16) + TSDB_TABLE_ID_LEN,
+    .maxRowSize   = sizeof(SSuperTableObj) + sizeof(SSchema) * (TSDB_MAX_TAGS + TSDB_MAX_COLUMNS + 16) + TSDB_TABLE_FNAME_LEN,
     .refCountPos  = (int8_t *)(&tObj.refCount) - (int8_t *)&tObj,
     .keyType      = SDB_KEY_VAR_STRING,
     .insertFp     = mnodeSuperTableActionInsert,
@@ -751,7 +751,7 @@ static int32_t mnodeProcessDropTableMsg(SMnodeMsg *pMsg) {
   if (pMsg->pTable == NULL) pMsg->pTable = mnodeGetTable(pDrop->tableId);
   if (pMsg->pTable == NULL) {
     if (pDrop->igNotExists) {
-      mDebug("app:%p:%p, table:%s, table is not exist, think drop success", pMsg->rpcMsg.ahandle, pMsg, pDrop->tableId);
+      mDebug("app:%p:%p, table:%s, table is not exist, treat as success", pMsg->rpcMsg.ahandle, pMsg, pDrop->tableId);
       return TSDB_CODE_SUCCESS;
     } else {
       mError("app:%p:%p, table:%s, failed to drop table, table not exist", pMsg->rpcMsg.ahandle, pMsg, pDrop->tableId);
@@ -1464,7 +1464,7 @@ static int32_t mnodeProcessSuperTableVgroupMsg(SMnodeMsg *pMsg) {
   // reserve space
   int32_t contLen = sizeof(SCMSTableVgroupRspMsg) + 32 * sizeof(SCMVgroupInfo) + sizeof(SVgroupsInfo); 
   for (int32_t i = 0; i < numOfTable; ++i) {
-    char *stableName = (char*)pInfo + sizeof(SCMSTableVgroupMsg) + (TSDB_TABLE_ID_LEN) * i;
+    char *stableName = (char*)pInfo + sizeof(SCMSTableVgroupMsg) + (TSDB_TABLE_FNAME_LEN) * i;
     SSuperTableObj *pTable = mnodeGetSuperTable(stableName);
     if (pTable != NULL && pTable->vgHash != NULL) {
       contLen += (taosHashGetSize(pTable->vgHash) * sizeof(SCMVgroupInfo) + sizeof(SVgroupsInfo));
@@ -1481,7 +1481,7 @@ static int32_t mnodeProcessSuperTableVgroupMsg(SMnodeMsg *pMsg) {
   char *msg = (char *)pRsp + sizeof(SCMSTableVgroupRspMsg);
 
   for (int32_t i = 0; i < numOfTable; ++i) {
-    char *          stableName = (char *)pInfo + sizeof(SCMSTableVgroupMsg) + (TSDB_TABLE_ID_LEN)*i;
+    char *          stableName = (char *)pInfo + sizeof(SCMSTableVgroupMsg) + (TSDB_TABLE_FNAME_LEN)*i;
     SSuperTableObj *pTable = mnodeGetSuperTable(stableName);
     if (pTable == NULL) {
       mError("app:%p:%p, stable:%s, not exist while get stable vgroup info", pMsg->rpcMsg.ahandle, pMsg, stableName);
@@ -1828,7 +1828,7 @@ static int32_t mnodeSendDropChildTableMsg(SMnodeMsg *pMsg, bool needReturn) {
     return TSDB_CODE_MND_OUT_OF_MEMORY;
   }
 
-  tstrncpy(pDrop->tableId, pTable->info.tableId, TSDB_TABLE_ID_LEN);
+  tstrncpy(pDrop->tableId, pTable->info.tableId, TSDB_TABLE_FNAME_LEN);
   pDrop->vgId    = htonl(pTable->vgId);
   pDrop->contLen = htonl(sizeof(SMDDropTableMsg));
   pDrop->sid     = htonl(pTable->sid);
@@ -2079,7 +2079,7 @@ static int32_t mnodeDoGetChildTableMeta(SMnodeMsg *pMsg, STableMetaMsg *pMeta) {
   pMeta->sid       = htonl(pTable->sid);
   pMeta->precision = pDb->cfg.precision;
   pMeta->tableType = pTable->info.type;
-  tstrncpy(pMeta->tableId, pTable->info.tableId, TSDB_TABLE_ID_LEN);
+  tstrncpy(pMeta->tableId, pTable->info.tableId, TSDB_TABLE_FNAME_LEN);
 
   if (pTable->info.type == TSDB_CHILD_TABLE) {
     pMeta->sversion     = htons(pTable->superTable->sversion);
@@ -2448,7 +2448,7 @@ static int32_t mnodeProcessMultiTableMetaMsg(SMnodeMsg *pMsg) {
   pMultiMeta->numOfTables = 0;
 
   for (int32_t t = 0; t < pInfo->numOfTables; ++t) {
-    char * tableId = (char *)(pInfo->tableIds + t * TSDB_TABLE_ID_LEN);
+    char * tableId = (char *)(pInfo->tableIds + t * TSDB_TABLE_FNAME_LEN);
     SChildTableObj *pTable = mnodeGetChildTable(tableId);
     if (pTable == NULL) continue;
 
diff --git a/src/plugins/http/src/httpContext.c b/src/plugins/http/src/httpContext.c
index e367911695..f7694ded97 100644
--- a/src/plugins/http/src/httpContext.c
+++ b/src/plugins/http/src/httpContext.c
@@ -167,8 +167,8 @@ bool httpInitContext(HttpContext *pContext) {
   memset(pParser, 0, sizeof(HttpParser));
   pParser->pCur = pParser->pLast = pParser->buffer;
 
-  httpDebug("context:%p, fd:%d, ip:%s, thread:%s, accessTimes:%d, parsed:%d",
-          pContext, pContext->fd, pContext->ipstr, pContext->pThread->label, pContext->accessTimes, pContext->parsed);
+  httpDebug("context:%p, fd:%d, ip:%s, accessTimes:%d, parsed:%d", pContext, pContext->fd, pContext->ipstr,
+            pContext->accessTimes, pContext->parsed);
   return true;
 }
 
diff --git a/src/plugins/monitor/src/monitorMain.c b/src/plugins/monitor/src/monitorMain.c
index 6c7ecbb951..32f5966e2d 100644
--- a/src/plugins/monitor/src/monitorMain.c
+++ b/src/plugins/monitor/src/monitorMain.c
@@ -192,7 +192,7 @@ static void dnodeBuildMonitorSql(char *sql, int32_t cmd) {
     snprintf(sql, SQL_LENGTH,
              "create table if not exists %s.slowquery(ts timestamp, username "
              "binary(%d), created_time timestamp, time bigint, sql binary(%d))",
-             tsMonitorDbName, TSDB_TABLE_ID_LEN - 1, TSDB_SLOW_QUERY_SQL_LEN);
+             tsMonitorDbName, TSDB_TABLE_FNAME_LEN - 1, TSDB_SLOW_QUERY_SQL_LEN);
   } else if (cmd == MONITOR_CMD_CREATE_TB_LOG) {
     snprintf(sql, SQL_LENGTH,
              "create table if not exists %s.log(ts timestamp, level tinyint, "
diff --git a/src/query/inc/qAst.h b/src/query/inc/qAst.h
index 01b4c16ac1..ec568a6cdb 100644
--- a/src/query/inc/qAst.h
+++ b/src/query/inc/qAst.h
@@ -48,7 +48,7 @@ typedef struct tQueryInfo {
   SSchema       sch;      // schema of tags
   char*         q;
   __compar_fn_t compare;  // filter function
-  void*         param;    // STSchema
+  bool          indexed;  // indexed columns
 } tQueryInfo;
 
 typedef struct SExprTraverseSupp {
diff --git a/src/query/inc/qExecutor.h b/src/query/inc/qExecutor.h
index bd2e0a4470..c7026b45c6 100644
--- a/src/query/inc/qExecutor.h
+++ b/src/query/inc/qExecutor.h
@@ -52,10 +52,10 @@ typedef struct SWindowStatus {
 
 typedef struct SWindowResult {
   uint16_t      numOfRows;   // number of rows of current  time window
+  SWindowStatus status;      // this result status: closed or opened
   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;      // this result status: closed or opened
 } SWindowResult;
 
 /**
@@ -122,6 +122,7 @@ typedef struct SQueryCostInfo {
   uint32_t discardBlocks;
   uint64_t elapsedTime;
   uint64_t computTime;
+  uint64_t internalSupSize;
 } SQueryCostInfo;
 
 typedef struct SQuery {
@@ -184,10 +185,8 @@ enum {
 
 typedef struct SQInfo {
   void*            signature;
-  int32_t          pointsInterpo;
-  int32_t          code;  // error code to returned to client
-//  sem_t            dataReady;
-
+  int32_t          code;   // error code to returned to client
+  pthread_t        owner; // if it is in execution
   void*            tsdb;
   int32_t          vgId;
   STableGroupInfo  tableGroupInfo;       // table id list < only includes the STable list>
diff --git a/src/query/inc/qExtbuffer.h b/src/query/inc/qExtbuffer.h
index 36fc0c9820..0bdcf5c45e 100644
--- a/src/query/inc/qExtbuffer.h
+++ b/src/query/inc/qExtbuffer.h
@@ -29,7 +29,7 @@ extern "C" {
 
 #define MAX_TMPFILE_PATH_LENGTH        PATH_MAX
 #define INITIAL_ALLOCATION_BUFFER_SIZE 64
-#define DEFAULT_PAGE_SIZE              (4096L)  // 16k larger than the SHistoInfo
+#define DEFAULT_PAGE_SIZE              (1024L)  // 16k larger than the SHistoInfo
 
 typedef enum EXT_BUFFER_FLUSH_MODEL {
   /*
diff --git a/src/query/inc/sql.y b/src/query/inc/sql.y
index 15cfeee6b2..2b2a967edf 100644
--- a/src/query/inc/sql.y
+++ b/src/query/inc/sql.y
@@ -26,7 +26,12 @@
 #include <string.h>
 #include <assert.h>
 #include <stdbool.h>
+#include "qSqlparser.h"
+#include "tcmdtype.h"
+#include "tstoken.h"
+#include "ttokendef.h"
 #include "tutil.h"
+#include "tvariant.h"
 }
 
 %syntax_error {
@@ -254,7 +259,7 @@ alter_db_optr(Y) ::= alter_db_optr(Z) keep(X).        { Y = Z; Y.keep = X; }
 alter_db_optr(Y) ::= alter_db_optr(Z) blocks(X).      { Y = Z; Y.numOfBlocks = strtol(X.z, NULL, 10); }
 alter_db_optr(Y) ::= alter_db_optr(Z) comp(X).        { Y = Z; Y.compressionLevel = strtol(X.z, NULL, 10); }
 alter_db_optr(Y) ::= alter_db_optr(Z) wal(X).         { Y = Z; Y.walLevel = strtol(X.z, NULL, 10); }
-alter_db_optr(Y) ::= alter_db_optr(Z) fsync(X).       { Y = Z; Y.fsyncPeriod = strtod(X.z, NULL, 10); }
+alter_db_optr(Y) ::= alter_db_optr(Z) fsync(X).       { Y = Z; Y.fsyncPeriod = strtol(X.z, NULL, 10); }
 
 %type typename {TAOS_FIELD}
 typename(A) ::= ids(X). { 
@@ -422,8 +427,35 @@ as(X) ::= .             { X.n = 0;  }
 from(A) ::= FROM tablelist(X).                 {A = X;}
 
 %type tablelist {tVariantList*}
-tablelist(A) ::= ids(X) cpxName(Y).                     { toTSDBType(X.type); X.n += Y.n; A = tVariantListAppendToken(NULL, &X, -1);}
-tablelist(A) ::= tablelist(Y) COMMA ids(X) cpxName(Z).  { toTSDBType(X.type); X.n += Z.n; A = tVariantListAppendToken(Y, &X, -1);   }
+tablelist(A) ::= ids(X) cpxName(Y).                     {
+  toTSDBType(X.type);
+  X.n += Y.n;
+  A = tVariantListAppendToken(NULL, &X, -1);
+  A = tVariantListAppendToken(A, &X, -1);  // table alias name
+}
+
+tablelist(A) ::= ids(X) cpxName(Y) ids(Z).             {
+   toTSDBType(X.type);
+   toTSDBType(Z.type);
+   X.n += Y.n;
+   A = tVariantListAppendToken(NULL, &X, -1);
+   A = tVariantListAppendToken(A, &Z, -1);
+}
+
+tablelist(A) ::= tablelist(Y) COMMA ids(X) cpxName(Z).  {
+  toTSDBType(X.type);
+  X.n += Z.n;
+  A = tVariantListAppendToken(Y, &X, -1);
+  A = tVariantListAppendToken(A, &X, -1);
+}
+
+tablelist(A) ::= tablelist(Y) COMMA ids(X) cpxName(Z) ids(F). {
+   toTSDBType(X.type);
+   toTSDBType(F.type);
+   X.n += Z.n;
+   A = tVariantListAppendToken(Y, &X, -1);
+   A = tVariantListAppendToken(A, &F, -1);
+}
 
 // The value of interval should be the form of "number+[a,s,m,h,d,n,y]" or "now"
 %type tmvar {SSQLToken}
diff --git a/src/query/src/qAst.c b/src/query/src/qAst.c
index e2d609a62c..afa3618a96 100644
--- a/src/query/src/qAst.c
+++ b/src/query/src/qAst.c
@@ -427,8 +427,9 @@ static void tQueryIndexColumn(SSkipList* pSkipList, tQueryInfo* pQueryInfo, SArr
         if (ret != 0) {
           break;
         }
-        
-        taosArrayPush(result, SL_GET_NODE_DATA(pNode));
+
+        STableKeyInfo info = {.pTable = *(void**)SL_GET_NODE_DATA(pNode), .lastKey = TSKEY_INITIAL_VAL};
+        taosArrayPush(result, &info);
       }
     } else if (optr == TSDB_RELATION_GREATER || optr == TSDB_RELATION_GREATER_EQUAL) { // greater equal
       bool comp = true;
@@ -445,7 +446,8 @@ static void tQueryIndexColumn(SSkipList* pSkipList, tQueryInfo* pQueryInfo, SArr
         if (ret == 0 && optr == TSDB_RELATION_GREATER) {
           continue;
         } else {
-          taosArrayPush(result, SL_GET_NODE_DATA(pNode));
+          STableKeyInfo info = {.pTable = *(void**)SL_GET_NODE_DATA(pNode), .lastKey = TSKEY_INITIAL_VAL};
+          taosArrayPush(result, &info);
           comp = false;
         }
       }
@@ -458,8 +460,9 @@ static void tQueryIndexColumn(SSkipList* pSkipList, tQueryInfo* pQueryInfo, SArr
         if (comp) {
           continue;
         }
-        
-        taosArrayPush(result, SL_GET_NODE_DATA(pNode));
+
+        STableKeyInfo info = {.pTable = *(void**)SL_GET_NODE_DATA(pNode), .lastKey = TSKEY_INITIAL_VAL};
+        taosArrayPush(result, &info);
       }
       
       tSkipListDestroyIter(iter);
@@ -472,8 +475,9 @@ static void tQueryIndexColumn(SSkipList* pSkipList, tQueryInfo* pQueryInfo, SArr
         if (comp) {
           continue;
         }
-  
-        taosArrayPush(result, SL_GET_NODE_DATA(pNode));
+
+        STableKeyInfo info = {.pTable = *(void**)SL_GET_NODE_DATA(pNode), .lastKey = TSKEY_INITIAL_VAL};
+        taosArrayPush(result, &info);
       }
   
     } else {
@@ -496,12 +500,14 @@ static void tQueryIndexColumn(SSkipList* pSkipList, tQueryInfo* pQueryInfo, SArr
         if (ret == 0 && optr == TSDB_RELATION_LESS) {
           continue;
         } else {
-          taosArrayPush(result, SL_GET_NODE_DATA(pNode));
+          STableKeyInfo info = {.pTable = *(void**)SL_GET_NODE_DATA(pNode), .lastKey = TSKEY_INITIAL_VAL};
+          taosArrayPush(result, &info);
           comp = false;  // no need to compare anymore
         }
       }
     }
   }
+
   free(cond.start); 
   free(cond.end);
   tSkipListDestroyIter(iter);
@@ -689,7 +695,8 @@ static void tQueryIndexlessColumn(SSkipList* pSkipList, tQueryInfo* pQueryInfo,
     }
 
     if (addToResult) {
-      taosArrayPush(res, pData);
+      STableKeyInfo info = {.pTable = *(void**)pData, .lastKey = TSKEY_INITIAL_VAL};
+      taosArrayPush(res, &info);
     }
   }
 
@@ -716,7 +723,7 @@ void tExprTreeTraverse(tExprNode *pExpr, SSkipList *pSkipList, SArray *result, S
     }
 
     tQueryInfo *pQueryInfo = pExpr->_node.info;
-    if (pQueryInfo->sch.colId == PRIMARYKEY_TIMESTAMP_COL_INDEX && pQueryInfo->optr != TSDB_RELATION_LIKE) {
+    if (pQueryInfo->indexed && pQueryInfo->optr != TSDB_RELATION_LIKE) {
       tQueryIndexColumn(pSkipList, pQueryInfo, result);
     } else {
       tQueryIndexlessColumn(pSkipList, pQueryInfo, result, param->nodeFilterFn);
diff --git a/src/query/src/qExecutor.c b/src/query/src/qExecutor.c
index 3a31e5b9eb..7f6fac3631 100644
--- a/src/query/src/qExecutor.c
+++ b/src/query/src/qExecutor.c
@@ -130,6 +130,9 @@ static void finalizeQueryResult(SQueryRuntimeEnv *pRuntimeEnv);
     (tw)->ekey = (tw)->skey + ((_q)->intervalTime - 1);               \
   } while (0)
 
+#define SET_STABLE_QUERY_OVER(_q) ((_q)->tableIndex = (_q)->tableqinfoGroupInfo.numOfTables)
+#define IS_STASBLE_QUERY_OVER(_q) ((_q)->tableIndex >= (_q)->tableqinfoGroupInfo.numOfTables)
+
 // todo move to utility
 static int32_t mergeIntoGroupResultImpl(SQInfo *pQInfo, SArray *group);
 
@@ -400,8 +403,16 @@ static SWindowResult *doSetTimeWindowFromKey(SQueryRuntimeEnv *pRuntimeEnv, SWin
 
     // more than the capacity, reallocate the resources
     if (pWindowResInfo->size >= pWindowResInfo->capacity) {
-      int64_t newCap = (int64_t)(pWindowResInfo->capacity * 1.5f);
+      int64_t newCap = 0;
+      if (pWindowResInfo->capacity > 10000) {
+        newCap = pWindowResInfo->capacity * 1.25;
+      } else {
+        newCap = pWindowResInfo->capacity * 1.5;
+      }
+
       char *t = realloc(pWindowResInfo->pResult, newCap * sizeof(SWindowResult));
+      pRuntimeEnv->summary.internalSupSize += (newCap - pWindowResInfo->capacity) * sizeof(SWindowResult);
+
       if (t == NULL) {
         longjmp(pRuntimeEnv->env, TSDB_CODE_QRY_OUT_OF_MEMORY);
       }
@@ -411,6 +422,8 @@ static SWindowResult *doSetTimeWindowFromKey(SQueryRuntimeEnv *pRuntimeEnv, SWin
       int32_t inc = (int32_t)newCap - pWindowResInfo->capacity;
       memset(&pWindowResInfo->pResult[pWindowResInfo->capacity], 0, sizeof(SWindowResult) * inc);
 
+      pRuntimeEnv->summary.internalSupSize += (pQuery->numOfOutput * sizeof(SResultInfo) + pRuntimeEnv->interBufSize) * inc;
+
       for (int32_t i = pWindowResInfo->capacity; i < newCap; ++i) {
         createQueryResultInfo(pQuery, &pWindowResInfo->pResult[i], pRuntimeEnv->stableQuery, pRuntimeEnv->interBufSize);
       }
@@ -1823,10 +1836,14 @@ static void doExchangeTimeWindow(SQInfo* pQInfo) {
   for(int32_t i = 0; i < t; ++i) {
     SArray* p1 = GET_TABLEGROUP(pQInfo, i);
 
+    SArray* tableKeyGroup = taosArrayGetP(pQInfo->tableGroupInfo.pGroupList, i);
     size_t len = taosArrayGetSize(p1);
     for(int32_t j = 0; j < len; ++j) {
       STableQueryInfo* pTableQueryInfo = (STableQueryInfo*) taosArrayGetP(p1, j);
       SWAP(pTableQueryInfo->win.skey, pTableQueryInfo->win.ekey, TSKEY);
+
+      STableKeyInfo* pInfo = taosArrayGet(tableKeyGroup, j);
+      pInfo->lastKey = pTableQueryInfo->win.skey;
     }
   }
 }
@@ -2225,7 +2242,7 @@ static void ensureOutputBufferSimple(SQueryRuntimeEnv* pRuntimeEnv, int32_t capa
 static void ensureOutputBuffer(SQueryRuntimeEnv* pRuntimeEnv, SDataBlockInfo* pBlockInfo) {
   // in case of prj/diff query, ensure the output buffer is sufficient to accommodate the results of current block
   SQuery* pQuery = pRuntimeEnv->pQuery;
-  if (!QUERY_IS_INTERVAL_QUERY(pQuery) && !pRuntimeEnv->groupbyNormalCol && !isFixedOutputQuery(pRuntimeEnv)) {
+  if (!QUERY_IS_INTERVAL_QUERY(pQuery) && !pRuntimeEnv->groupbyNormalCol && !isFixedOutputQuery(pRuntimeEnv) && !isTSCompQuery(pQuery)) {
     SResultRec *pRec = &pQuery->rec;
     
     if (pQuery->rec.capacity - pQuery->rec.rows < pBlockInfo->rows) {
@@ -2662,6 +2679,10 @@ int32_t mergeIntoGroupResult(SQInfo *pQInfo) {
     qDebug("QInfo:%p no result in group %d, continue", pQInfo, pQInfo->groupIndex - 1);
   }
 
+  if (pQInfo->groupIndex == numOfGroups && pQInfo->offset == pQInfo->numOfGroupResultPages) {
+    SET_STABLE_QUERY_OVER(pQInfo);
+  }
+
   qDebug("QInfo:%p merge res data into group, index:%d, total group:%d, elapsed time:%" PRId64 "ms", pQInfo,
          pQInfo->groupIndex - 1, numOfGroups, taosGetTimestampMs() - st);
 
@@ -2680,7 +2701,7 @@ void copyResToQueryResultBuf(SQInfo *pQInfo, SQuery *pQuery) {
     // check if all results has been sent to client
     int32_t numOfGroup = (int32_t)(GET_NUM_OF_TABLEGROUP(pQInfo));
     if (pQInfo->numOfGroupResultPages == 0 && pQInfo->groupIndex == numOfGroup) {
-      pQInfo->tableIndex = (int32_t)pQInfo->tableqinfoGroupInfo.numOfTables;  // set query completed
+      SET_STABLE_QUERY_OVER(pQInfo);
       return;
     }
   }
@@ -2704,8 +2725,7 @@ void copyResToQueryResultBuf(SQInfo *pQInfo, SQuery *pQuery) {
       memcpy(pDest + offset * bytes, pData->data + pRuntimeEnv->offset[i] * pData->num, bytes * pData->num);
     }
 
-//    rows += pData->num;
-    offset += (int32_t)pData->num;
+    offset += pData->num;
   }
 
   assert(pQuery->rec.rows == 0);
@@ -2790,14 +2810,20 @@ int32_t mergeIntoGroupResultImpl(SQInfo *pQInfo, SArray *pGroup) {
   setWindowResultInfo(pResultInfo, pQuery, pRuntimeEnv->stableQuery, buf);
   resetMergeResultBuf(pQuery, pRuntimeEnv->pCtx, pResultInfo);
 
+  // todo add windowRes iterator
   int64_t lastTimestamp = -1;
   int64_t startt = taosGetTimestampMs();
 
   while (1) {
+    if (IS_QUERY_KILLED(pQInfo)) {
+      qDebug("QInfo:%p it is already killed, abort", pQInfo);
+      longjmp(pRuntimeEnv->env, TSDB_CODE_TSC_QUERY_CANCELLED);
+    }
+
     int32_t pos = pTree->pNode[0].index;
 
     SWindowResInfo *pWindowResInfo = &pTableList[pos]->windowResInfo;
-    SWindowResult * pWindowRes = getWindowResult(pWindowResInfo, cs.position[pos]);
+    SWindowResult  *pWindowRes = getWindowResult(pWindowResInfo, cs.position[pos]);
     tFilePage *page = getResBufPage(pRuntimeEnv->pResultBuf, pWindowRes->pos.pageId);
 
     char *b = getPosInResultPage(pRuntimeEnv, PRIMARYKEY_TIMESTAMP_COL_INDEX, pWindowRes, page);
@@ -2834,6 +2860,9 @@ int32_t mergeIntoGroupResultImpl(SQInfo *pQInfo, SArray *pGroup) {
 
       lastTimestamp = ts;
 
+      // move to the next element of current entry
+      int32_t currentPageId = pWindowRes->pos.pageId;
+
       cs.position[pos] += 1;
       if (cs.position[pos] >= pWindowResInfo->size) {
         cs.position[pos] = -1;
@@ -2842,6 +2871,12 @@ int32_t mergeIntoGroupResultImpl(SQInfo *pQInfo, SArray *pGroup) {
         if (--numOfTables == 0) {
           break;
         }
+      } else {
+        // current page is not needed anymore
+        SWindowResult  *pNextWindowRes = getWindowResult(pWindowResInfo, cs.position[pos]);
+        if (pNextWindowRes->pos.pageId != currentPageId) {
+          releaseResBufPage(pRuntimeEnv->pResultBuf, page);
+        }
       }
     }
 
@@ -2935,7 +2970,7 @@ static void updateTableQueryInfoForReverseScan(SQuery *pQuery, STableQueryInfo *
     return;
   }
   
-  // order has change already!
+  // order has changed already
   int32_t step = GET_FORWARD_DIRECTION_FACTOR(pQuery->order.order);
   
   // TODO validate the assertion
@@ -2944,9 +2979,13 @@ static void updateTableQueryInfoForReverseScan(SQuery *pQuery, STableQueryInfo *
 //  } else {
 //    assert(pTableQueryInfo->win.ekey <= pTableQueryInfo->lastKey + step);
 //  }
-  
-  pTableQueryInfo->win.ekey = pTableQueryInfo->lastKey + step;
-  
+
+  if (pTableQueryInfo->lastKey == pTableQueryInfo->win.skey) {
+    // do nothing, no results
+  } else {
+    pTableQueryInfo->win.ekey = pTableQueryInfo->lastKey + step;
+  }
+
   SWAP(pTableQueryInfo->win.skey, pTableQueryInfo->win.ekey, TSKEY);
   pTableQueryInfo->lastKey = pTableQueryInfo->win.skey;
   
@@ -3008,16 +3047,26 @@ void disableFuncInReverseScan(SQInfo *pQInfo) {
       }
     }
   }
-  
-  int32_t numOfGroups = (int32_t)(GET_NUM_OF_TABLEGROUP(pQInfo));
-  
+}
+
+static void setupQueryRangeForReverseScan(SQInfo* pQInfo) {
+  SQuery* pQuery = pQInfo->runtimeEnv.pQuery;
+  int32_t numOfGroups = GET_NUM_OF_TABLEGROUP(pQInfo);
+
   for(int32_t i = 0; i < numOfGroups; ++i) {
     SArray *group = GET_TABLEGROUP(pQInfo, i);
-    
+    SArray *tableKeyGroup = taosArrayGetP(pQInfo->tableGroupInfo.pGroupList, i);
+
     size_t t = taosArrayGetSize(group);
     for (int32_t j = 0; j < t; ++j) {
       STableQueryInfo *pCheckInfo = taosArrayGetP(group, j);
       updateTableQueryInfoForReverseScan(pQuery, pCheckInfo);
+
+      // update the last key in tableKeyInfo list
+      STableKeyInfo *pTableKeyInfo = taosArrayGet(tableKeyGroup, j);
+      pTableKeyInfo->lastKey = pCheckInfo->lastKey;
+
+      assert(pCheckInfo->pTable == pTableKeyInfo->pTable);
     }
   }
 }
@@ -3266,20 +3315,20 @@ static void setEnvBeforeReverseScan(SQueryRuntimeEnv *pRuntimeEnv, SQueryStatusI
 
   TIME_WINDOW_COPY(cond.twindow, pQuery->window);
 
+  setQueryStatus(pQuery, QUERY_NOT_COMPLETED);
+  switchCtxOrder(pRuntimeEnv);
+  disableFuncInReverseScan(pQInfo);
+  setupQueryRangeForReverseScan(pQInfo);
+
   // clean unused handle
   if (pRuntimeEnv->pSecQueryHandle != NULL) {
     tsdbCleanupQueryHandle(pRuntimeEnv->pSecQueryHandle);
   }
 
-  // add ref for table
   pRuntimeEnv->pSecQueryHandle = tsdbQueryTables(pQInfo->tsdb, &cond, &pQInfo->tableGroupInfo, pQInfo);
   if (pRuntimeEnv->pSecQueryHandle == NULL) {
     longjmp(pRuntimeEnv->env, terrno);
   }
-
-  setQueryStatus(pQuery, QUERY_NOT_COMPLETED);
-  switchCtxOrder(pRuntimeEnv);
-  disableFuncInReverseScan(pQInfo);
 }
 
 static void clearEnvAfterReverseScan(SQueryRuntimeEnv *pRuntimeEnv, SQueryStatusInfo *pStatus) {
@@ -3304,6 +3353,13 @@ static void clearEnvAfterReverseScan(SQueryRuntimeEnv *pRuntimeEnv, SQueryStatus
   pQuery->window = pTableQueryInfo->win;
 }
 
+static void restoreTimeWindow(STableGroupInfo* pTableGroupInfo, STsdbQueryCond* pCond) {
+  assert(pTableGroupInfo->numOfTables == 1);
+  SArray* pTableKeyGroup = taosArrayGetP(pTableGroupInfo->pGroupList, 0);
+  STableKeyInfo* pKeyInfo = taosArrayGet(pTableKeyGroup, 0);
+  pKeyInfo->lastKey = pCond->twindow.skey;
+}
+
 void scanOneTableDataBlocks(SQueryRuntimeEnv *pRuntimeEnv, TSKEY start) {
   SQInfo *pQInfo = (SQInfo *) GET_QINFO_ADDR(pRuntimeEnv);
   SQuery *pQuery = pRuntimeEnv->pQuery;
@@ -3352,6 +3408,7 @@ void scanOneTableDataBlocks(SQueryRuntimeEnv *pRuntimeEnv, TSKEY start) {
       tsdbCleanupQueryHandle(pRuntimeEnv->pSecQueryHandle);
     }
 
+    restoreTimeWindow(&pQInfo->tableGroupInfo, &cond);
     pRuntimeEnv->pSecQueryHandle = tsdbQueryTables(pQInfo->tsdb, &cond, &pQInfo->tableGroupInfo, pQInfo);
     if (pRuntimeEnv->pSecQueryHandle == NULL) {
       longjmp(pRuntimeEnv->env, terrno);
@@ -3800,7 +3857,7 @@ static void stableApplyFunctionsOnBlock(SQueryRuntimeEnv *pRuntimeEnv, SDataBloc
   }
 }
 
-bool queryHasRemainResults(SQueryRuntimeEnv* pRuntimeEnv) {
+bool queryHasRemainResForTableQuery(SQueryRuntimeEnv* pRuntimeEnv) {
   SQuery *pQuery = pRuntimeEnv->pQuery;
   SFillInfo *pFillInfo = pRuntimeEnv->pFillInfo;
 
@@ -3809,8 +3866,7 @@ bool queryHasRemainResults(SQueryRuntimeEnv* pRuntimeEnv) {
   }
 
   if (pQuery->fillType != TSDB_FILL_NONE && !isPointInterpoQuery(pQuery)) {
-    // There are results not returned to client yet, so filling operation applied to the remain result is required
-    // in the first place.
+    // There are results not returned to client yet, so filling applied to the remain result is required firstly.
     int32_t remain = taosNumOfRemainRows(pFillInfo);
     if (remain > 0) {
       return true;
@@ -3864,14 +3920,14 @@ static void doCopyQueryResultToMsg(SQInfo *pQInfo, int32_t numOfRows, char *data
     data += sizeof(STableIdInfo);
   }
 
-  // all data returned, set query over
+  // Check if query is completed or not for stable query or normal table query respectively.
   if (Q_STATUS_EQUAL(pQuery->status, QUERY_COMPLETED)) {
     if (pQInfo->runtimeEnv.stableQuery) {
-      if (pQInfo->tableIndex >= pQInfo->tableqinfoGroupInfo.numOfTables) {
+      if (IS_STASBLE_QUERY_OVER(pQInfo)) {
         setQueryStatus(pQuery, QUERY_OVER);
       }
     } else {
-      if (!queryHasRemainResults(&pQInfo->runtimeEnv)) {
+      if (!queryHasRemainResForTableQuery(&pQInfo->runtimeEnv)) {
         setQueryStatus(pQuery, QUERY_OVER);
       }
     }
@@ -3917,7 +3973,7 @@ int32_t doFillGapsInResults(SQueryRuntimeEnv* pRuntimeEnv, tFilePage **pDst, int
       ret = 0;
     }
 
-    if (!queryHasRemainResults(pRuntimeEnv)) {
+    if (!queryHasRemainResForTableQuery(pRuntimeEnv)) {
       return ret;
     }
   }
@@ -3931,6 +3987,8 @@ static void queryCostStatis(SQInfo *pQInfo) {
          " load data block:%d, total rows:%"PRId64 ", check rows:%"PRId64,
          pQInfo, pSummary->elapsedTime, pSummary->totalBlocks, pSummary->loadBlockStatis,
          pSummary->loadBlocks, pSummary->totalRows, pSummary->totalCheckedRows);
+
+  qDebug("QInfo:%p :cost summary: internal size:%"PRId64, pQInfo, pSummary->internalSupSize);
 }
 
 static void updateOffsetVal(SQueryRuntimeEnv *pRuntimeEnv, SDataBlockInfo *pBlockInfo) {
@@ -4425,9 +4483,11 @@ static bool multiTableMultioutputHelper(SQInfo *pQInfo, int32_t index) {
 
   // todo refactor
   SArray *g1 = taosArrayInit(1, POINTER_BYTES);
-  SArray *tx = taosArrayInit(1, POINTER_BYTES);
+  SArray *tx = taosArrayInit(1, sizeof(STableKeyInfo));
+
+  STableKeyInfo info = {.pTable = pCheckInfo->pTable, .lastKey = pCheckInfo->lastKey};
+  taosArrayPush(tx, &info);
 
-  taosArrayPush(tx, &pCheckInfo->pTable);
   taosArrayPush(g1, &tx);
   STableGroupInfo gp = {.numOfTables = 1, .pGroupList = g1};
 
@@ -4579,7 +4639,9 @@ static void sequentialTableProcess(SQInfo *pQInfo) {
         pRuntimeEnv->pQueryHandle = NULL;
       }
 
+      // no need to update the lastkey for each table
       pRuntimeEnv->pQueryHandle = tsdbQueryTables(pQInfo->tsdb, &cond, &gp, pQInfo);
+
       taosArrayDestroy(g1);
       taosArrayDestroy(tx);
       if (pRuntimeEnv->pQueryHandle == NULL) {
@@ -4680,7 +4742,7 @@ static void sequentialTableProcess(SQInfo *pQInfo) {
 
       // the limitation of output result is reached, set the query completed
       if (limitResults(pRuntimeEnv)) {
-        pQInfo->tableIndex = (int32_t)pQInfo->tableqinfoGroupInfo.numOfTables;
+        SET_STABLE_QUERY_OVER(pQInfo);
         break;
       }
 
@@ -4705,8 +4767,7 @@ static void sequentialTableProcess(SQInfo *pQInfo) {
         taosArrayPush(pQInfo->arrTableIdInfo, &tidInfo);
 
         // if the buffer is full or group by each table, we need to jump out of the loop
-        if (Q_STATUS_EQUAL(pQuery->status, QUERY_RESBUF_FULL) /*||
-            isGroupbyEachTable(pQuery->pGroupbyExpr, pSupporter->pSidSet)*/) {
+        if (Q_STATUS_EQUAL(pQuery->status, QUERY_RESBUF_FULL)) {
           break;
         }
 
@@ -4770,7 +4831,7 @@ static void doSaveContext(SQInfo *pQInfo) {
       .colList = pQuery->colList,
       .numOfCols = pQuery->numOfCols,
   };
-  
+
   TIME_WINDOW_COPY(cond.twindow, pQuery->window);
 
   // clean unused handle
@@ -4778,15 +4839,16 @@ static void doSaveContext(SQInfo *pQInfo) {
     tsdbCleanupQueryHandle(pRuntimeEnv->pSecQueryHandle);
   }
 
+  setQueryStatus(pQuery, QUERY_NOT_COMPLETED);
+  switchCtxOrder(pRuntimeEnv);
+  disableFuncInReverseScan(pQInfo);
+  setupQueryRangeForReverseScan(pQInfo);
+
   pRuntimeEnv->prevGroupId = INT32_MIN;
   pRuntimeEnv->pSecQueryHandle = tsdbQueryTables(pQInfo->tsdb, &cond, &pQInfo->tableGroupInfo, pQInfo);
   if (pRuntimeEnv->pSecQueryHandle == NULL) {
     longjmp(pRuntimeEnv->env, terrno);
   }
-
-  setQueryStatus(pQuery, QUERY_NOT_COMPLETED);
-  switchCtxOrder(pRuntimeEnv);
-  disableFuncInReverseScan(pQInfo);
 }
 
 static void doRestoreContext(SQInfo *pQInfo) {
@@ -5070,15 +5132,13 @@ static void tableIntervalProcess(SQInfo *pQInfo, STableQueryInfo* pTableInfo) {
     copyFromWindowResToSData(pQInfo, &pRuntimeEnv->windowResInfo);
     clearFirstNTimeWindow(pRuntimeEnv, pQInfo->groupIndex);
   }
-
-  pQInfo->pointsInterpo += numOfFilled;
 }
 
 static void tableQueryImpl(SQInfo *pQInfo) {
   SQueryRuntimeEnv *pRuntimeEnv = &pQInfo->runtimeEnv;
   SQuery *          pQuery = pRuntimeEnv->pQuery;
 
-  if (queryHasRemainResults(pRuntimeEnv)) {
+  if (queryHasRemainResForTableQuery(pRuntimeEnv)) {
 
     if (pQuery->fillType != TSDB_FILL_NONE) {
       /*
@@ -5859,7 +5919,7 @@ static SQInfo *createQInfoImpl(SQueryTableMsg *pQueryMsg, SArray* pTableIdList,
     pQInfo->tableqinfoGroupInfo.pGroupList = taosArrayInit(numOfGroups, POINTER_BYTES);
     pQInfo->tableqinfoGroupInfo.numOfTables = pTableGroupInfo->numOfTables;
     pQInfo->tableqinfoGroupInfo.map = taosHashInit(pTableGroupInfo->numOfTables,
-                                                   taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), false);
+                                                   taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), true, false);
   }
 
   int tableIndex = 0;
@@ -5880,8 +5940,8 @@ static SQInfo *createQInfoImpl(SQueryTableMsg *pQueryMsg, SArray* pTableIdList,
     }
 
     for(int32_t j = 0; j < s; ++j) {
-      void* pTable = taosArrayGetP(pa, j);
-      STableId* id = TSDB_TABLEID(pTable);
+      STableKeyInfo* info = taosArrayGet(pa, j);
+      STableId* id = TSDB_TABLEID(info->pTable);
 
       STableIdInfo* pTableId = taosArraySearch(pTableIdList, id, compareTableIdInfo);
       if (pTableId != NULL ) {
@@ -5891,10 +5951,11 @@ static SQInfo *createQInfoImpl(SQueryTableMsg *pQueryMsg, SArray* pTableIdList,
       }
 
       void* buf = (char*)pQInfo->pBuf + index * sizeof(STableQueryInfo);
-      STableQueryInfo* item = createTableQueryInfo(&pQInfo->runtimeEnv, pTable, window, buf);
+      STableQueryInfo* item = createTableQueryInfo(&pQInfo->runtimeEnv, info->pTable, window, buf);
       if (item == NULL) {
         goto _cleanup;
       }
+
       item->groupIndex = i;
       taosArrayPush(p1, &item);
       taosHashPut(pQInfo->tableqinfoGroupInfo.map, &id->tid, sizeof(id->tid), &item, POINTER_BYTES);
@@ -5923,6 +5984,7 @@ _cleanup_query:
     taosArrayDestroy(pGroupbyExpr->columnInfo);
     free(pGroupbyExpr);
   }
+
   taosTFree(pTagCols);
   for (int32_t i = 0; i < numOfOutput; ++i) {
     SExprInfo* pExprInfo = &pExprs[i];
@@ -5930,6 +5992,7 @@ _cleanup_query:
       tExprTreeDestroy(&pExprInfo->pExpr, NULL);
     }
   }
+
   taosTFree(pExprs);
 
 _cleanup:
@@ -6011,8 +6074,6 @@ static void freeQInfo(SQInfo *pQInfo) {
   }
 
   SQuery *pQuery = pQInfo->runtimeEnv.pQuery;
-  setQueryKilled(pQInfo);
-
   qDebug("QInfo:%p start to free QInfo", pQInfo);
   for (int32_t col = 0; col < pQuery->numOfOutput; ++col) {
     taosTFree(pQuery->sdata[col]);
@@ -6217,7 +6278,7 @@ int32_t qCreateQueryInfo(void* tsdb, int32_t vgId, SQueryTableMsg* pQueryMsg, qi
     STableIdInfo *id = taosArrayGet(pTableIdList, 0);
 
     qDebug("qmsg:%p query normal table, uid:%"PRId64", tid:%d", pQueryMsg, id->uid, id->tid);
-    if ((code = tsdbGetOneTableGroup(tsdb, id->uid, &tableGroupInfo)) != TSDB_CODE_SUCCESS) {
+    if ((code = tsdbGetOneTableGroup(tsdb, id->uid, pQueryMsg->window.skey, &tableGroupInfo)) != TSDB_CODE_SUCCESS) {
       goto _over;
     }
   } else if (TSDB_QUERY_HAS_TYPE(pQueryMsg->queryType, TSDB_QUERY_TYPE_MULTITABLE_QUERY|TSDB_QUERY_TYPE_STABLE_QUERY)) {
@@ -6234,8 +6295,9 @@ int32_t qCreateQueryInfo(void* tsdb, int32_t vgId, SQueryTableMsg* pQueryMsg, qi
       }
 
       qDebug("qmsg:%p query stable, uid:%"PRId64", tid:%d", pQueryMsg, id->uid, id->tid);
-      code = tsdbQuerySTableByTagCond(tsdb, id->uid, tagCond, pQueryMsg->tagCondLen, pQueryMsg->tagNameRelType, tbnameCond, &tableGroupInfo, pGroupColIndex,
-                                          numOfGroupByCols);
+      code = tsdbQuerySTableByTagCond(tsdb, id->uid, pQueryMsg->window.skey, tagCond, pQueryMsg->tagCondLen,
+          pQueryMsg->tagNameRelType, tbnameCond, &tableGroupInfo, pGroupColIndex, numOfGroupByCols);
+
       if (code != TSDB_CODE_SUCCESS) {
         qError("qmsg:%p failed to query stable, reason: %s", pQueryMsg, tstrerror(code));
         goto _over;
@@ -6315,14 +6377,22 @@ static bool doBuildResCheck(SQInfo* pQInfo) {
 
   pthread_mutex_unlock(&pQInfo->lock);
 
+  // clear qhandle owner
+  assert(pQInfo->owner == pthread_self());
+  pQInfo->owner = 0;
+
   return buildRes;
 }
 
 bool qTableQuery(qinfo_t qinfo) {
   SQInfo *pQInfo = (SQInfo *)qinfo;
+  assert(pQInfo && pQInfo->signature == pQInfo);
+  int64_t threadId = pthread_self();
 
-  if (pQInfo == NULL || pQInfo->signature != pQInfo) {
-    qDebug("QInfo:%p has been freed, no need to execute", pQInfo);
+  int64_t curOwner = 0;
+  if ((curOwner = atomic_val_compare_exchange_64(&pQInfo->owner, 0, threadId)) != 0) {
+    qError("QInfo:%p qhandle is now executed by thread:%p", pQInfo, (void*) curOwner);
+    pQInfo->code = TSDB_CODE_QRY_IN_EXEC;
     return false;
   }
 
@@ -6377,6 +6447,7 @@ int32_t qRetrieveQueryResultInfo(qinfo_t qinfo, bool* buildRes, void* pRspContex
     return TSDB_CODE_QRY_INVALID_QHANDLE;
   }
 
+  *buildRes = false;
   SQuery *pQuery = pQInfo->runtimeEnv.pQuery;
   if (IS_QUERY_KILLED(pQInfo)) {
     qDebug("QInfo:%p query is killed, code:%d", pQInfo, pQInfo->code);
@@ -6400,34 +6471,6 @@ int32_t qRetrieveQueryResultInfo(qinfo_t qinfo, bool* buildRes, void* pRspContex
   return code;
 }
 
-bool qHasMoreResultsToRetrieve(qinfo_t qinfo) {
-  SQInfo *pQInfo = (SQInfo *)qinfo;
-
-  if (!isValidQInfo(pQInfo) || pQInfo->code != TSDB_CODE_SUCCESS) {
-    qDebug("QInfo:%p invalid qhandle or error occurs, abort query, code:%x", pQInfo, pQInfo->code);
-    return false;
-  }
-
-  SQuery *pQuery = pQInfo->runtimeEnv.pQuery;
-
-  bool ret = false;
-  if (Q_STATUS_EQUAL(pQuery->status, QUERY_OVER)) {
-    ret = false;
-  } else if (Q_STATUS_EQUAL(pQuery->status, QUERY_RESBUF_FULL)) {
-    ret = true;
-  } else if (Q_STATUS_EQUAL(pQuery->status, QUERY_COMPLETED)) {
-    ret = true;
-  } else {
-    assert(0);
-  }
-
-  if (ret) {
-    qDebug("QInfo:%p has more results waits for client retrieve", pQInfo);
-  }
-
-  return ret;
-}
-
 int32_t qDumpRetrieveResult(qinfo_t qinfo, SRetrieveTableRsp **pRsp, int32_t *contLen, bool* continueExec) {
   SQInfo *pQInfo = (SQInfo *)qinfo;
 
@@ -6455,11 +6498,11 @@ int32_t qDumpRetrieveResult(qinfo_t qinfo, SRetrieveTableRsp **pRsp, int32_t *co
 
   int32_t code = pQInfo->code;
   if (code == TSDB_CODE_SUCCESS) {
-    (*pRsp)->offset = htobe64(pQuery->limit.offset);
+    (*pRsp)->offset   = htobe64(pQuery->limit.offset);
     (*pRsp)->useconds = htobe64(pRuntimeEnv->summary.elapsedTime);
   } else {
-    (*pRsp)->useconds = 0;
-    (*pRsp)->offset = 0;
+    (*pRsp)->offset   = 0;
+    (*pRsp)->useconds = htobe64(pRuntimeEnv->summary.elapsedTime);
   }
   
   (*pRsp)->precision = htons(pQuery->precision);
@@ -6471,22 +6514,30 @@ int32_t qDumpRetrieveResult(qinfo_t qinfo, SRetrieveTableRsp **pRsp, int32_t *co
   }
 
   pQInfo->rspContext = NULL;
-  pQInfo->dataReady = QUERY_RESULT_NOT_READY;
+  pQInfo->dataReady  = QUERY_RESULT_NOT_READY;
 
   if (IS_QUERY_KILLED(pQInfo) || Q_STATUS_EQUAL(pQuery->status, QUERY_OVER)) {
-    (*pRsp)->completed = 1;  // notify no more result to client
-  }
-
-  if (qHasMoreResultsToRetrieve(pQInfo)) {
-    *continueExec = true;
-  } else { // failed to dump result, free qhandle immediately
     *continueExec = false;
-    qKillQuery(pQInfo);
+    (*pRsp)->completed = 1;  // notify no more result to client
+  } else {
+    *continueExec = true;
+    qDebug("QInfo:%p has more results waits for client retrieve", pQInfo);
   }
 
   return code;
 }
 
+int32_t qQueryCompleted(qinfo_t qinfo) {
+  SQInfo *pQInfo = (SQInfo *)qinfo;
+
+  if (pQInfo == NULL || !isValidQInfo(pQInfo)) {
+    return TSDB_CODE_QRY_INVALID_QHANDLE;
+  }
+
+  SQuery* pQuery = pQInfo->runtimeEnv.pQuery;
+  return IS_QUERY_KILLED(pQInfo) || Q_STATUS_EQUAL(pQuery->status, QUERY_OVER);
+}
+
 int32_t qKillQuery(qinfo_t qinfo) {
   SQInfo *pQInfo = (SQInfo *)qinfo;
 
@@ -6495,6 +6546,13 @@ int32_t qKillQuery(qinfo_t qinfo) {
   }
 
   setQueryKilled(pQInfo);
+
+  // Wait for the query executing thread being stopped/
+  // Once the query is stopped, the owner of qHandle will be cleared immediately.
+  while(pQInfo->owner != 0) {
+    taosMsleep(100);
+  }
+
   return TSDB_CODE_SUCCESS;
 }
 
@@ -6589,7 +6647,7 @@ static void buildTagQueryResult(SQInfo* pQInfo) {
     *(int64_t*) pQuery->sdata[0]->data = num;
 
     count = 1;
-    pQInfo->tableIndex = (int32_t)num;  //set query completed
+    SET_STABLE_QUERY_OVER(pQInfo);
     qDebug("QInfo:%p create count(tbname) query, res:%d rows:1", pQInfo, count);
   } else {  // return only the tags|table name etc.
     count = 0;
@@ -6661,7 +6719,7 @@ void freeqinfoFn(void *qhandle) {
 }
 
 void* qOpenQueryMgmt(int32_t vgId) {
-  const int32_t REFRESH_HANDLE_INTERVAL = 30; // every 30 seconds, refresh handle pool
+  const int32_t REFRESH_HANDLE_INTERVAL = 60; // every 30 seconds, refresh handle pool
 
   char cacheName[128] = {0};
   sprintf(cacheName, "qhandle_%d", vgId);
@@ -6691,9 +6749,9 @@ void qQueryMgmtNotifyClosed(void* pQMgmt) {
   SQueryMgmt* pQueryMgmt = pQMgmt;
   qDebug("vgId:%d, set querymgmt closed, wait for all queries cancelled", pQueryMgmt->vgId);
 
-  pthread_mutex_lock(&pQueryMgmt->lock);
+//  pthread_mutex_lock(&pQueryMgmt->lock);
   pQueryMgmt->closed = true;
-  pthread_mutex_unlock(&pQueryMgmt->lock);
+//  pthread_mutex_unlock(&pQueryMgmt->lock);
 
   taosCacheRefresh(pQueryMgmt->qinfoPool, queryMgmtKillQueryFn);
 }
@@ -6723,7 +6781,7 @@ void** qRegisterQInfo(void* pMgmt, uint64_t qInfo) {
     return NULL;
   }
 
-  const int32_t DEFAULT_QHANDLE_LIFE_SPAN = tsShellActivityTimer * 2;
+  const int32_t DEFAULT_QHANDLE_LIFE_SPAN = tsShellActivityTimer * 2 * 1000;
 
   SQueryMgmt *pQueryMgmt = pMgmt;
   if (pQueryMgmt->qinfoPool == NULL) {
@@ -6731,16 +6789,16 @@ void** qRegisterQInfo(void* pMgmt, uint64_t qInfo) {
     return NULL;
   }
 
-  pthread_mutex_lock(&pQueryMgmt->lock);
+//  pthread_mutex_lock(&pQueryMgmt->lock);
   if (pQueryMgmt->closed) {
-    pthread_mutex_unlock(&pQueryMgmt->lock);
+//    pthread_mutex_unlock(&pQueryMgmt->lock);
     qError("QInfo:%p failed to add qhandle into cache, since qMgmt is colsing", (void *)qInfo);
     return NULL;
   } else {
     uint64_t handleVal = (uint64_t) qInfo;
 
     void** handle = taosCachePut(pQueryMgmt->qinfoPool, &handleVal, sizeof(int64_t), &qInfo, POINTER_BYTES, DEFAULT_QHANDLE_LIFE_SPAN);
-    pthread_mutex_unlock(&pQueryMgmt->lock);
+//    pthread_mutex_unlock(&pQueryMgmt->lock);
 
     return handle;
   }
@@ -6763,7 +6821,6 @@ void** qAcquireQInfo(void* pMgmt, uint64_t key) {
 
 void** qReleaseQInfo(void* pMgmt, void* pQInfo, bool freeHandle) {
   SQueryMgmt *pQueryMgmt = pMgmt;
-
   if (pQueryMgmt->qinfoPool == NULL) {
     return NULL;
   }
diff --git a/src/query/src/qExtbuffer.c b/src/query/src/qExtbuffer.c
index fcc17a0c9e..a147780144 100644
--- a/src/query/src/qExtbuffer.c
+++ b/src/query/src/qExtbuffer.c
@@ -12,15 +12,14 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
-#include "qExtbuffer.h"
 #include "os.h"
+#include "qExtbuffer.h"
 #include "queryLog.h"
 #include "taos.h"
 #include "taosdef.h"
 #include "taosmsg.h"
 #include "tsqlfunction.h"
 #include "tulog.h"
-#include "tutil.h"
 
 #define COLMODEL_GET_VAL(data, schema, allrow, rowId, colId) \
   (data + (schema)->pFields[colId].offset * (allrow) + (rowId) * (schema)->pFields[colId].field.bytes)
diff --git a/src/query/src/qResultbuf.c b/src/query/src/qResultbuf.c
index a300cc6382..7c40c33933 100644
--- a/src/query/src/qResultbuf.c
+++ b/src/query/src/qResultbuf.c
@@ -6,7 +6,8 @@
 #include "queryLog.h"
 #include "taoserror.h"
 
-#define GET_DATA_PAYLOAD(_p) ((tFilePage*)(((char*)(_p)->pData) + POINTER_BYTES))
+#define GET_DATA_PAYLOAD(_p) ((_p)->pData + POINTER_BYTES)
+#define NO_IN_MEM_AVAILABLE_PAGES(_b) (listNEles((_b)->lruList) >= (_b)->inMemPages)
 
 int32_t createDiskbasedResultBuffer(SDiskbasedResultBuf** pResultBuf, int32_t rowSize, int32_t pagesize,
                                     int32_t inMemBufSize, const void* handle) {
@@ -25,7 +26,7 @@ int32_t createDiskbasedResultBuffer(SDiskbasedResultBuf** pResultBuf, int32_t ro
   pResBuf->comp         = true;
   pResBuf->file         = NULL;
   pResBuf->handle       = handle;
-  pResBuf->fileSize = 0;
+  pResBuf->fileSize     = 0;
 
   // at least more than 2 pages must be in memory
   assert(inMemBufSize >= pagesize * 2);
@@ -34,9 +35,9 @@ int32_t createDiskbasedResultBuffer(SDiskbasedResultBuf** pResultBuf, int32_t ro
   pResBuf->lruList = tdListNew(POINTER_BYTES);
 
   // init id hash table
-  pResBuf->groupSet  = taosHashInit(10, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), false);
+  pResBuf->groupSet  = taosHashInit(10, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), true, false);
   pResBuf->assistBuf = malloc(pResBuf->pageSize + 2); // EXTRA BYTES
-  pResBuf->all = taosHashInit(10, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), false);
+  pResBuf->all = taosHashInit(10, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), true, false);
 
   char path[PATH_MAX] = {0};
   taosGetTmpfilePath("qbuf", path);
@@ -186,8 +187,6 @@ static char* loadPageFromDisk(SDiskbasedResultBuf* pResultBuf, SPageInfo* pg) {
   return (char*)GET_DATA_PAYLOAD(pg);
 }
 
-#define NO_AVAILABLE_PAGES(_b) ((_b)->numOfPages >= (_b)->inMemPages)
-
 static SIDList addNewGroup(SDiskbasedResultBuf* pResultBuf, int32_t groupId) {
   assert(taosHashGet(pResultBuf->groupSet, (const char*) &groupId, sizeof(int32_t)) == NULL);
 
@@ -211,11 +210,12 @@ static SPageInfo* registerPage(SDiskbasedResultBuf* pResultBuf, int32_t groupId,
   pResultBuf->numOfPages += 1;
 
   SPageInfo* ppi = malloc(sizeof(SPageInfo));//{ .info = PAGE_INFO_INITIALIZER, .pageId = pageId, .pn = NULL};
-  ppi->info     = PAGE_INFO_INITIALIZER;
-  ppi->pageId   = pageId;
-  ppi->pData    = NULL;
-  ppi->pn       = NULL;
-  ppi->used     = true;
+
+  ppi->pageId = pageId;
+  ppi->pData  = NULL;
+  ppi->info   = PAGE_INFO_INITIALIZER;
+  ppi->used   = true;
+  ppi->pn     = NULL;
 
   return *(SPageInfo**) taosArrayPush(list, &ppi);
 }
@@ -246,7 +246,9 @@ static char* evicOneDataPage(SDiskbasedResultBuf* pResultBuf) {
   // all pages are referenced by user, try to allocate new space
   if (pn == NULL) {
     int32_t prev = pResultBuf->inMemPages;
-    pResultBuf->inMemPages = (int32_t)(pResultBuf->inMemPages * 1.5f);
+
+    // increase by 50% of previous mem pages
+    pResultBuf->inMemPages = pResultBuf->inMemPages * 1.5f;
 
     qWarn("%p in memory buf page not sufficient, expand from %d to %d, page size:%d", pResultBuf, prev,
           pResultBuf->inMemPages, pResultBuf->pageSize);
@@ -281,7 +283,7 @@ tFilePage* getNewDataBuf(SDiskbasedResultBuf* pResultBuf, int32_t groupId, int32
   pResultBuf->statis.getPages += 1;
 
   char* availablePage = NULL;
-  if (NO_AVAILABLE_PAGES(pResultBuf)) {
+  if (NO_IN_MEM_AVAILABLE_PAGES(pResultBuf)) {
     availablePage = evicOneDataPage(pResultBuf);
   }
 
@@ -340,7 +342,7 @@ tFilePage* getResBufPage(SDiskbasedResultBuf* pResultBuf, int32_t id) {
     assert((*pi)->pData == NULL && (*pi)->pn == NULL && (*pi)->info.length >= 0 && (*pi)->info.offset >= 0);
 
     char* availablePage = NULL;
-    if (NO_AVAILABLE_PAGES(pResultBuf)) {
+    if (NO_IN_MEM_AVAILABLE_PAGES(pResultBuf)) {
       availablePage = evicOneDataPage(pResultBuf);
     }
 
@@ -353,6 +355,8 @@ tFilePage* getResBufPage(SDiskbasedResultBuf* pResultBuf, int32_t id) {
     ((void**)((*pi)->pData))[0] = (*pi);
 
     lruListPushFront(pResultBuf->lruList, *pi);
+    (*pi)->used = true;
+
     loadPageFromDisk(pResultBuf, *pi);
     return GET_DATA_PAYLOAD(*pi);
   }
@@ -396,12 +400,13 @@ void destroyResultBuf(SDiskbasedResultBuf* pResultBuf) {
   }
 
   if (pResultBuf->file != NULL) {
-    qDebug("QInfo:%p disk-based output buffer closed, total:%" PRId64 " bytes, file size:%"PRId64" bytes",
-        pResultBuf->handle, pResultBuf->totalBufSize, pResultBuf->fileSize);
+    qDebug("QInfo:%p res output buffer closed, total:%" PRId64 " bytes, inmem size:%dbytes, file size:%"PRId64" bytes",
+        pResultBuf->handle, pResultBuf->totalBufSize, listNEles(pResultBuf->lruList) * pResultBuf->pageSize,
+        pResultBuf->fileSize);
 
     fclose(pResultBuf->file);
   } else {
-    qDebug("QInfo:%p disk-based output buffer closed, total:%" PRId64 " bytes, no file created", pResultBuf->handle,
+    qDebug("QInfo:%p res output buffer closed, total:%" PRId64 " bytes, no file created", pResultBuf->handle,
            pResultBuf->totalBufSize);
   }
 
diff --git a/src/query/src/qTokenizer.c b/src/query/src/qTokenizer.c
index d730b3cab0..227aded5f1 100644
--- a/src/query/src/qTokenizer.c
+++ b/src/query/src/qTokenizer.c
@@ -25,7 +25,7 @@
 // All the keywords of the SQL language are stored in a hash table
 typedef struct SKeyword {
   const char* name;  // The keyword name
-  uint16_t     type;  // type
+  uint16_t    type;  // type
   uint8_t     len;   // length
 } SKeyword;
 
@@ -257,7 +257,7 @@ static void* KeywordHashTable = NULL;
 static void doInitKeywordsTable(void) {
   int numOfEntries = tListLen(keywordTable);
   
-  KeywordHashTable = taosHashInit(numOfEntries, MurmurHash3_32, false);
+  KeywordHashTable = taosHashInit(numOfEntries, MurmurHash3_32, true, false);
   for (int32_t i = 0; i < numOfEntries; i++) {
     keywordTable[i].len = (uint8_t)strlen(keywordTable[i].name);
     void* ptr = &keywordTable[i];
diff --git a/src/query/src/qTsbuf.c b/src/query/src/qTsbuf.c
index ab7678a22b..25eb33ff7d 100644
--- a/src/query/src/qTsbuf.c
+++ b/src/query/src/qTsbuf.c
@@ -72,6 +72,7 @@ STSBuf* tsBufCreateFromFile(const char* path, bool autoDelete) {
 
   // invalid file
   if (header.magic != TS_COMP_FILE_MAGIC) {
+    tsBufDestroy(pTSBuf);
     return NULL;
   }
   
diff --git a/src/query/src/qUtil.c b/src/query/src/qUtil.c
index 7175262270..a01eb33ec7 100644
--- a/src/query/src/qUtil.c
+++ b/src/query/src/qUtil.c
@@ -37,7 +37,7 @@ int32_t initWindowResInfo(SWindowResInfo *pWindowResInfo, SQueryRuntimeEnv *pRun
   
   pWindowResInfo->type = type;
   _hash_fn_t fn = taosGetDefaultHashFunction(type);
-  pWindowResInfo->hashList = taosHashInit(threshold, fn, false);
+  pWindowResInfo->hashList = taosHashInit(threshold, fn, true, false);
   if (pWindowResInfo->hashList == NULL) {
     return TSDB_CODE_QRY_OUT_OF_MEMORY;
   }
@@ -46,12 +46,17 @@ int32_t initWindowResInfo(SWindowResInfo *pWindowResInfo, SQueryRuntimeEnv *pRun
   pWindowResInfo->size     = 0;
   pWindowResInfo->prevSKey = TSKEY_INITIAL_VAL;
   
+  pRuntimeEnv->summary.internalSupSize += sizeof(SWindowResult) * threshold;
+
   // use the pointer arraylist
   pWindowResInfo->pResult = calloc(threshold, sizeof(SWindowResult));
   if (pWindowResInfo->pResult == NULL) {
     return TSDB_CODE_QRY_OUT_OF_MEMORY;
   }
 
+  pRuntimeEnv->summary.internalSupSize += sizeof(SWindowResult) * threshold;
+  pRuntimeEnv->summary.internalSupSize += (pRuntimeEnv->pQuery->numOfOutput * sizeof(SResultInfo) + pRuntimeEnv->interBufSize) * pWindowResInfo->capacity;
+
   for (int32_t i = 0; i < pWindowResInfo->capacity; ++i) {
     int32_t code = createQueryResultInfo(pRuntimeEnv->pQuery, &pWindowResInfo->pResult[i], pRuntimeEnv->stableQuery, pRuntimeEnv->interBufSize);
     if (code != TSDB_CODE_SUCCESS) {
@@ -104,7 +109,7 @@ void resetTimeWindowInfo(SQueryRuntimeEnv *pRuntimeEnv, SWindowResInfo *pWindowR
   pWindowResInfo->size = 0;
   
   _hash_fn_t fn = taosGetDefaultHashFunction(pWindowResInfo->type);
-  pWindowResInfo->hashList = taosHashInit(pWindowResInfo->capacity, fn, false);
+  pWindowResInfo->hashList = taosHashInit(pWindowResInfo->capacity, fn, true, false);
   
   pWindowResInfo->startTime = TSKEY_INITIAL_VAL;
   pWindowResInfo->prevSKey = TSKEY_INITIAL_VAL;
diff --git a/src/query/src/sql.c b/src/query/src/sql.c
index fe26f61725..75ef2f3218 100644
--- a/src/query/src/sql.c
+++ b/src/query/src/sql.c
@@ -126,17 +126,17 @@ typedef union {
 #define ParseARG_FETCH SSqlInfo* pInfo = yypParser->pInfo
 #define ParseARG_STORE yypParser->pInfo = pInfo
 #define YYFALLBACK 1
-#define YYNSTATE             243
-#define YYNRULE              226
+#define YYNSTATE             245
+#define YYNRULE              228
 #define YYNTOKEN             207
-#define YY_MAX_SHIFT         242
-#define YY_MIN_SHIFTREDUCE   405
-#define YY_MAX_SHIFTREDUCE   630
-#define YY_ERROR_ACTION      631
-#define YY_ACCEPT_ACTION     632
-#define YY_NO_ACTION         633
-#define YY_MIN_REDUCE        634
-#define YY_MAX_REDUCE        859
+#define YY_MAX_SHIFT         244
+#define YY_MIN_SHIFTREDUCE   407
+#define YY_MAX_SHIFTREDUCE   634
+#define YY_ERROR_ACTION      635
+#define YY_ACCEPT_ACTION     636
+#define YY_NO_ACTION         637
+#define YY_MIN_REDUCE        638
+#define YY_MAX_REDUCE        865
 /************* End control #defines *******************************************/
 
 /* Define the yytestcase() macro to be a no-op if is not already defined
@@ -202,64 +202,64 @@ typedef union {
 **  yy_default[]       Default action for each state.
 **
 *********** Begin parsing tables **********************************************/
-#define YY_ACTTAB_COUNT (552)
+#define YY_ACTTAB_COUNT (554)
 static const YYACTIONTYPE yy_action[] = {
- /*     0 */   103,  446,  135,  673,  632,  242,  126,  515,  135,  447,
- /*    10 */   135,  158,  847,   41,   43,   11,   35,   36,  846,  157,
- /*    20 */   847,   29,  134,  446,  197,   39,   37,   40,   38,  155,
- /*    30 */   103,  447,  139,   34,   33,  217,  216,   32,   31,   30,
- /*    40 */    41,   43,  767,   35,   36,   32,   31,   30,   29,  756,
- /*    50 */   446,  197,   39,   37,   40,   38,  182,  802,  447,  192,
- /*    60 */    34,   33,   21,   21,   32,   31,   30,  406,  407,  408,
- /*    70 */   409,  410,  411,  412,  413,  414,  415,  416,  417,  241,
- /*    80 */    41,   43,  228,   35,   36,  194,  843,   58,   29,   21,
- /*    90 */   842,  197,   39,   37,   40,   38,  166,  167,  753,  753,
- /*   100 */    34,   33,  168,   56,   32,   31,   30,  778,  841,   16,
- /*   110 */   235,  208,  234,  233,  207,  206,  205,  232,  204,  231,
- /*   120 */   230,  229,  203,  215,  151,  753,  732,  586,  719,  720,
- /*   130 */   721,  722,  723,  724,  725,  726,  727,  728,  729,  730,
- /*   140 */   731,   43,    8,   35,   36,   61,  113,   21,   29,  153,
- /*   150 */   240,  197,   39,   37,   40,   38,  239,  238,   95,  775,
- /*   160 */    34,   33,  165,   99,   32,   31,   30,  169,   35,   36,
- /*   170 */   214,  213,  592,   29,  595,  103,  197,   39,   37,   40,
- /*   180 */    38,  220,  756,  753,  236,   34,   33,  175,   12,   32,
- /*   190 */    31,   30,  162,  599,  179,  178,  590,  767,  593,  103,
- /*   200 */   596,  161,  162,  599,  756,   17,  590,  148,  593,  152,
- /*   210 */   596,  154,   26,   88,   87,  142,  185,  567,  568,   16,
- /*   220 */   235,  147,  234,  233,  159,  160,  219,  232,  196,  231,
- /*   230 */   230,  229,  801,   76,  159,  160,  162,  599,  547,  228,
- /*   240 */   590,    3,  593,   17,  596,   74,   78,   83,   86,   77,
- /*   250 */    26,   39,   37,   40,   38,   80,   59,  754,   21,   34,
- /*   260 */    33,  544,   60,   32,   31,   30,   18,  140,  159,  160,
- /*   270 */   181,  737,  539,  736,   27,  734,  735,  150,  682,  184,
- /*   280 */   738,  126,  740,  741,  739,  674,  531,  141,  126,  528,
- /*   290 */    42,  529,  558,  530,  752,  591,   46,  594,   34,   33,
- /*   300 */    42,  598,   32,   31,   30,  116,  117,   68,   64,   67,
- /*   310 */   588,  598,  143,   50,   73,   72,  597,  170,  171,  130,
- /*   320 */   128,   91,   90,   89,   98,   47,  597,  144,  559,  616,
- /*   330 */    51,   26,   14,   13,   42,  145,  600,  521,  520,  201,
- /*   340 */    13,   46,   22,   22,   48,  598,  589,   10,    9,  535,
- /*   350 */   533,  536,  534,   85,   84,  146,  137,  133,  856,  138,
- /*   360 */   597,  136,  755,  812,  811,  163,  808,  807,  164,  777,
- /*   370 */   747,  218,  794,  100,  793,  769,  114,  115,   26,  684,
- /*   380 */   112,  202,  131,  183,   24,  211,  681,  212,  855,  532,
- /*   390 */    70,  854,   93,  852,  118,  702,  554,   25,   23,  132,
- /*   400 */   671,   79,   52,  186,  669,   81,   82,  667,  666,  172,
- /*   410 */   127,  664,  190,  663,  662,  661,  660,  652,  129,  658,
- /*   420 */    49,  656,  654,  766,  781,  782,  795,  104,  195,   44,
- /*   430 */   193,  191,  189,  187,  210,  105,   75,   28,  221,  199,
- /*   440 */   222,  223,   53,  225,  224,  149,  226,   62,   65,  703,
- /*   450 */   227,  237,  630,  173,  174,  629,  177,  665,  628,  119,
- /*   460 */   176,   92,  121,  125,  120,  751,  122,  123,  659,  124,
- /*   470 */   108,  106,  107,  109,  110,  111,   94,    1,    2,  621,
- /*   480 */   180,  184,  541,   55,   57,  555,  101,  156,  188,  198,
- /*   490 */    19,   63,    5,  560,  102,    4,    6,  601,   20,   15,
- /*   500 */     7,  488,  484,  200,  482,  481,  480,  477,  450,  209,
- /*   510 */    66,   45,   22,   69,   71,  517,  516,  514,  471,   54,
- /*   520 */   469,  461,  467,  463,  465,  459,  457,  487,  486,  485,
- /*   530 */   483,  479,  478,  476,   46,  448,  421,  419,  634,  633,
- /*   540 */   633,  633,  633,  633,  633,  633,  633,  633,  633,  633,
- /*   550 */    96,   97,
+ /*     0 */   105,  448,  137,  677,  636,  244,  128,  517,  137,  449,
+ /*    10 */   137,  160,  853,   41,   43,   11,   35,   36,  852,  159,
+ /*    20 */   853,   29,  136,  448,  199,   39,   37,   40,   38,  157,
+ /*    30 */   105,  449,  141,   34,   33,  219,  218,   32,   31,   30,
+ /*    40 */    41,   43,  771,   35,   36,   32,   31,   30,   29,  760,
+ /*    50 */   448,  199,   39,   37,   40,   38,  184,  808,  449,  194,
+ /*    60 */    34,   33,   21,   21,   32,   31,   30,  408,  409,  410,
+ /*    70 */   411,  412,  413,  414,  415,  416,  417,  418,  419,  243,
+ /*    80 */    41,   43,  230,   35,   36,  196,  849,   60,   29,   21,
+ /*    90 */   848,  199,   39,   37,   40,   38,  168,  169,  757,  757,
+ /*   100 */    34,   33,  170,   56,   32,   31,   30,  782,  847,   16,
+ /*   110 */   237,  210,  236,  235,  209,  208,  207,  234,  206,  233,
+ /*   120 */   232,  231,  205,  217,  153,  757,  736,  590,  723,  724,
+ /*   130 */   725,  726,  727,  728,  729,  730,  731,  732,  733,  734,
+ /*   140 */   735,   43,    8,   35,   36,   63,  115,   21,   29,  155,
+ /*   150 */   242,  199,   39,   37,   40,   38,  241,  240,   97,  779,
+ /*   160 */    34,   33,  167,  101,   32,   31,   30,  171,   35,   36,
+ /*   170 */   216,  215,  596,   29,  599,  105,  199,   39,   37,   40,
+ /*   180 */    38,  222,  760,  757,  238,   34,   33,  177,   12,   32,
+ /*   190 */    31,   30,  164,  603,  181,  180,  594,  771,  597,  105,
+ /*   200 */   600,  163,  164,  603,  760,   17,  594,  150,  597,  154,
+ /*   210 */   600,  156,   26,   90,   89,  144,  187,  571,  572,   16,
+ /*   220 */   237,  149,  236,  235,  161,  162,  221,  234,  198,  233,
+ /*   230 */   232,  231,  807,   78,  161,  162,  164,  603,  549,  230,
+ /*   240 */   594,    3,  597,   17,  600,   76,   80,   85,   88,   79,
+ /*   250 */    26,   39,   37,   40,   38,   82,   61,  758,   21,   34,
+ /*   260 */    33,  546,   62,   32,   31,   30,   18,  142,  161,  162,
+ /*   270 */   183,  741,  541,  740,   27,  738,  739,  152,  686,  186,
+ /*   280 */   742,  128,  744,  745,  743,  678,  533,  143,  128,  530,
+ /*   290 */    42,  531,  562,  532,  756,  595,   46,  598,   34,   33,
+ /*   300 */    42,  602,   32,   31,   30,  118,  119,   70,   66,   69,
+ /*   310 */   592,  602,  145,   50,   75,   74,  601,  172,  173,  132,
+ /*   320 */   130,   93,   92,   91,  100,   47,  601,  146,  563,  620,
+ /*   330 */    51,   26,   14,   13,   42,  147,  604,  523,  522,  203,
+ /*   340 */    13,   46,   22,   22,   48,  602,  593,   10,    9,  537,
+ /*   350 */   535,  538,  536,   87,   86,  148,  139,  135,  862,  140,
+ /*   360 */   601,  138,  759,  818,  817,  165,  814,  813,  166,  781,
+ /*   370 */   751,  220,  800,  786,  788,  773,  102,  799,   26,  116,
+ /*   380 */   114,  117,  688,  185,  204,  133,   24,  213,  685,  534,
+ /*   390 */   214,  861,   95,   72,  860,  858,  558,  120,  706,   25,
+ /*   400 */    23,  134,   52,  188,  675,   81,  673,   83,   84,  671,
+ /*   410 */   670,  174,  192,  129,  668,  667,  666,  665,  664,  656,
+ /*   420 */    49,  131,  662,  660,  658,  770,   57,   58,  801,   44,
+ /*   430 */   197,  195,  193,  191,  189,   28,  106,  212,   77,  223,
+ /*   440 */   224,  225,  226,  201,   53,  227,  228,  229,  239,   64,
+ /*   450 */    67,  634,  151,  175,  176,  633,  178,  179,  632,  669,
+ /*   460 */   186,  625,   94,   96,  123,  127,    2,  122,  707,  755,
+ /*   470 */   121,  124,  125,  111,  107,  108,  126,  109,  110,  112,
+ /*   480 */   663,  113,  182,    1,  543,   55,   59,  559,  103,  158,
+ /*   490 */   564,    5,  190,  104,    6,   65,  490,  605,    4,   19,
+ /*   500 */    20,   15,  200,    7,  202,  486,  484,  483,  482,  479,
+ /*   510 */   452,  211,   68,   45,   22,   71,   73,  519,  518,  516,
+ /*   520 */    54,  473,  471,  463,  469,  465,  467,  461,  459,  489,
+ /*   530 */   488,  487,  485,  481,  480,  478,   46,  450,  423,  421,
+ /*   540 */   638,  637,  637,  637,  637,  637,  637,  637,  637,  637,
+ /*   550 */   637,  637,   98,   99,
 };
 static const YYCODETYPE yy_lookahead[] = {
  /*     0 */   211,    1,  262,  215,  208,  209,  218,    5,  262,    9,
@@ -299,25 +299,25 @@ static const YYCODETYPE yy_lookahead[] = {
  /*   340 */   104,  104,  104,  104,  123,  110,   37,  129,  130,    5,
  /*   350 */     5,    7,    7,   72,   73,  262,  262,  262,  248,  262,
  /*   360 */   125,  262,  248,  243,  243,  243,  243,  243,  243,  211,
- /*   370 */   244,  243,  269,  211,  269,  246,  211,  211,  106,  211,
+ /*   370 */   244,  243,  269,  211,  211,  246,  211,  269,  106,  211,
  /*   380 */   250,  211,  211,  246,  211,  211,  211,  211,  211,  105,
  /*   390 */   211,  211,   59,  211,  211,  211,  110,  211,  211,  211,
  /*   400 */   211,  211,  120,  265,  211,  211,  211,  211,  211,  211,
  /*   410 */   211,  211,  265,  211,  211,  211,  211,  211,  211,  211,
- /*   420 */   122,  211,  211,  259,  212,  212,  212,  258,  114,  119,
- /*   430 */   118,  113,  112,  111,   75,  257,   84,  124,   83,  212,
- /*   440 */    49,   80,  212,   53,   82,  212,   81,  216,  216,  226,
- /*   450 */    79,   75,    5,  136,    5,    5,    5,  212,    5,  225,
- /*   460 */   136,  213,  220,  219,  224,  246,  223,  221,  212,  222,
- /*   470 */   254,  256,  255,  253,  252,  251,  213,  217,  214,   87,
- /*   480 */   127,  107,  100,  108,  104,  100,   99,    1,   99,  101,
- /*   490 */   104,   72,  115,  100,   99,   99,  115,  100,  104,   99,
- /*   500 */    99,    9,    5,  101,    5,    5,    5,    5,   76,   15,
- /*   510 */    72,   16,  104,  130,  130,    5,    5,  100,    5,   99,
- /*   520 */     5,    5,    5,    5,    5,    5,    5,    5,    5,    5,
- /*   530 */     5,    5,    5,    5,  104,   76,   59,   58,    0,  273,
- /*   540 */   273,  273,  273,  273,  273,  273,  273,  273,  273,  273,
- /*   550 */    21,   21,  273,  273,  273,  273,  273,  273,  273,  273,
+ /*   420 */   122,  211,  211,  211,  211,  259,  212,  212,  212,  119,
+ /*   430 */   114,  118,  113,  112,  111,  124,  258,   75,   84,   83,
+ /*   440 */    49,   80,   82,  212,  212,   53,   81,   79,   75,  216,
+ /*   450 */   216,    5,  212,  136,    5,    5,  136,    5,    5,  212,
+ /*   460 */   107,   87,  213,  213,  220,  219,  214,  224,  226,  246,
+ /*   470 */   225,  223,  221,  253,  257,  256,  222,  255,  254,  252,
+ /*   480 */   212,  251,  127,  217,  100,  108,  104,  100,   99,    1,
+ /*   490 */   100,  115,   99,   99,  115,   72,    9,  100,   99,  104,
+ /*   500 */   104,   99,  101,   99,  101,    5,    5,    5,    5,    5,
+ /*   510 */    76,   15,   72,   16,  104,  130,  130,    5,    5,  100,
+ /*   520 */    99,    5,    5,    5,    5,    5,    5,    5,    5,    5,
+ /*   530 */     5,    5,    5,    5,    5,    5,  104,   76,   59,   58,
+ /*   540 */     0,  273,  273,  273,  273,  273,  273,  273,  273,  273,
+ /*   550 */   273,  273,   21,   21,  273,  273,  273,  273,  273,  273,
  /*   560 */   273,  273,  273,  273,  273,  273,  273,  273,  273,  273,
  /*   570 */   273,  273,  273,  273,  273,  273,  273,  273,  273,  273,
  /*   580 */   273,  273,  273,  273,  273,  273,  273,  273,  273,  273,
@@ -337,83 +337,84 @@ static const YYCODETYPE yy_lookahead[] = {
  /*   720 */   273,  273,  273,  273,  273,  273,  273,  273,  273,  273,
  /*   730 */   273,  273,  273,  273,  273,  273,  273,  273,  273,  273,
  /*   740 */   273,  273,  273,  273,  273,  273,  273,  273,  273,  273,
- /*   750 */   273,  273,  273,  273,  273,  273,  273,  273,  273,
+ /*   750 */   273,  273,  273,  273,  273,  273,  273,  273,  273,  273,
+ /*   760 */   273,
 };
-#define YY_SHIFT_COUNT    (242)
+#define YY_SHIFT_COUNT    (244)
 #define YY_SHIFT_MIN      (0)
-#define YY_SHIFT_MAX      (538)
+#define YY_SHIFT_MAX      (540)
 static const unsigned short int yy_shift_ofst[] = {
  /*     0 */   144,   24,  134,  191,  235,   49,   49,   49,   49,   49,
  /*    10 */    49,    0,   22,  235,  284,  284,  284,  106,   49,   49,
- /*    20 */    49,   49,   49,  161,    4,    4,  552,  201,  235,  235,
+ /*    20 */    49,   49,   49,  161,    4,    4,  554,  201,  235,  235,
  /*    30 */   235,  235,  235,  235,  235,  235,  235,  235,  235,  235,
  /*    40 */   235,  235,  235,  235,  235,  284,  284,    2,    2,    2,
- /*    50 */     2,    2,    2,   43,    2,  225,   49,   49,  101,  101,
- /*    60 */   157,   49,   49,   49,   49,   49,   49,   49,   49,   49,
+ /*    50 */     2,    2,    2,   43,    2,  225,   49,   49,   49,   49,
+ /*    60 */   101,  101,  157,   49,   49,   49,   49,   49,   49,   49,
  /*    70 */    49,   49,   49,   49,   49,   49,   49,   49,   49,   49,
  /*    80 */    49,   49,   49,   49,   49,   49,   49,   49,   49,   49,
- /*    90 */    49,   49,   49,   49,   49,   49,   49,   49,  272,  333,
- /*   100 */   333,  286,  286,  333,  282,  298,  310,  314,  312,  318,
- /*   110 */   320,  322,  313,  272,  333,  333,  359,  359,  333,  352,
- /*   120 */   355,  391,  361,  362,  390,  365,  371,  333,  376,  333,
- /*   130 */   376,  552,  552,   27,   67,   67,   67,  127,  152,  226,
- /*   140 */   226,  226,  181,  265,  265,  265,  265,  241,  255,   39,
- /*   150 */    60,    8,    8,   96,  172,  192,  228,  229,  236,  167,
- /*   160 */   290,  309,  142,  221,  209,  237,  238,  239,  185,  218,
- /*   170 */   344,  345,  281,  447,  317,  449,  450,  324,  451,  453,
- /*   180 */   392,  353,  374,  382,  375,  380,  385,  387,  486,  389,
- /*   190 */   393,  395,  386,  377,  394,  381,  397,  396,  400,  388,
- /*   200 */   401,  402,  419,  492,  497,  499,  500,  501,  502,  432,
- /*   210 */   494,  438,  495,  383,  384,  408,  510,  511,  417,  420,
- /*   220 */   408,  513,  515,  516,  517,  518,  519,  520,  521,  522,
- /*   230 */   523,  524,  525,  526,  527,  528,  430,  459,  529,  530,
- /*   240 */   477,  479,  538,
+ /*    90 */    49,   49,   49,   49,   49,   49,   49,   49,   49,   49,
+ /*   100 */   272,  333,  333,  286,  286,  333,  282,  298,  310,  316,
+ /*   110 */   313,  319,  321,  323,  311,  272,  333,  333,  362,  362,
+ /*   120 */   333,  354,  356,  391,  361,  360,  392,  365,  368,  333,
+ /*   130 */   373,  333,  373,  554,  554,   27,   67,   67,   67,  127,
+ /*   140 */   152,  226,  226,  226,  181,  265,  265,  265,  265,  241,
+ /*   150 */   255,   39,   60,    8,    8,   96,  172,  192,  228,  229,
+ /*   160 */   236,  167,  290,  309,  142,  221,  209,  237,  238,  239,
+ /*   170 */   185,  218,  344,  345,  281,  446,  317,  449,  450,  320,
+ /*   180 */   452,  453,  374,  355,  353,  384,  377,  382,  387,  389,
+ /*   190 */   488,  393,  390,  394,  395,  376,  396,  379,  397,  399,
+ /*   200 */   402,  401,  404,  403,  423,  487,  500,  501,  502,  503,
+ /*   210 */   504,  434,  496,  440,  497,  385,  386,  410,  512,  513,
+ /*   220 */   419,  421,  410,  516,  517,  518,  519,  520,  521,  522,
+ /*   230 */   523,  524,  525,  526,  527,  528,  529,  530,  432,  461,
+ /*   240 */   531,  532,  479,  481,  540,
 };
-#define YY_REDUCE_COUNT (132)
+#define YY_REDUCE_COUNT (134)
 #define YY_REDUCE_MIN   (-260)
-#define YY_REDUCE_MAX   (264)
+#define YY_REDUCE_MAX   (268)
 static const short yy_reduce_ofst[] = {
  /*     0 */  -204, -101,   44, -260, -252, -211, -181, -149, -148, -122,
  /*    10 */   -64, -104,  -61, -254, -199,  -66,  -44,  -49,  -48,  -36,
  /*    20 */   -12,   15,   47, -212,   63,   70,   13, -247, -240, -230,
  /*    30 */  -176, -172, -154, -138,  -53,    5,   25,   50,   65,   73,
  /*    40 */    93,   94,   95,   97,   99,  110,  114,  120,  121,  122,
- /*    50 */   123,  124,  125,  126,  128,  129,  158,  162,  103,  105,
- /*    60 */   130,  165,  166,  168,  170,  171,  173,  174,  175,  176,
+ /*    50 */   123,  124,  125,  126,  128,  129,  158,  162,  163,  165,
+ /*    60 */   103,  108,  130,  168,  170,  171,  173,  174,  175,  176,
  /*    70 */   177,  179,  180,  182,  183,  184,  186,  187,  188,  189,
  /*    80 */   190,  193,  194,  195,  196,  197,  198,  199,  200,  202,
- /*    90 */   203,  204,  205,  206,  207,  208,  210,  211,  137,  212,
- /*   100 */   213,  138,  147,  214,  164,  169,  178,  215,  217,  216,
- /*   110 */   220,  222,  224,  219,  227,  230,  231,  232,  233,  223,
- /*   120 */   234,  240,  242,  243,  246,  247,  244,  245,  248,  256,
- /*   130 */   263,  260,  264,
+ /*    90 */   203,  204,  205,  206,  207,  208,  210,  211,  212,  213,
+ /*   100 */   137,  214,  215,  138,  147,  216,  166,  178,  217,  219,
+ /*   110 */   222,  224,  220,  227,  230,  223,  231,  232,  233,  234,
+ /*   120 */   240,  242,  245,  243,  244,  248,  251,  254,  246,  247,
+ /*   130 */   249,  268,  250,  266,  252,
 };
 static const YYACTIONTYPE yy_default[] = {
- /*     0 */   631,  683,  672,  849,  849,  631,  631,  631,  631,  631,
- /*    10 */   631,  779,  649,  849,  631,  631,  631,  631,  631,  631,
- /*    20 */   631,  631,  631,  685,  685,  685,  774,  631,  631,  631,
- /*    30 */   631,  631,  631,  631,  631,  631,  631,  631,  631,  631,
- /*    40 */   631,  631,  631,  631,  631,  631,  631,  631,  631,  631,
- /*    50 */   631,  631,  631,  631,  631,  631,  631,  631,  798,  798,
- /*    60 */   772,  631,  631,  631,  631,  631,  631,  631,  631,  631,
- /*    70 */   631,  631,  631,  631,  631,  631,  631,  631,  631,  670,
- /*    80 */   631,  668,  631,  631,  631,  631,  631,  631,  631,  631,
- /*    90 */   631,  631,  631,  631,  631,  657,  631,  631,  631,  651,
- /*   100 */   651,  631,  631,  651,  805,  809,  803,  791,  799,  790,
- /*   110 */   786,  785,  813,  631,  651,  651,  680,  680,  651,  701,
- /*   120 */   699,  697,  689,  695,  691,  693,  687,  651,  678,  651,
- /*   130 */   678,  718,  733,  631,  814,  848,  804,  832,  831,  844,
- /*   140 */   838,  837,  631,  836,  835,  834,  833,  631,  631,  631,
- /*   150 */   631,  840,  839,  631,  631,  631,  631,  631,  631,  631,
- /*   160 */   631,  631,  816,  810,  806,  631,  631,  631,  631,  631,
- /*   170 */   631,  631,  631,  631,  631,  631,  631,  631,  631,  631,
- /*   180 */   631,  631,  771,  631,  631,  780,  631,  631,  631,  631,
- /*   190 */   631,  631,  800,  631,  792,  631,  631,  631,  631,  631,
- /*   200 */   631,  748,  631,  631,  631,  631,  631,  631,  631,  631,
- /*   210 */   631,  631,  631,  631,  631,  853,  631,  631,  631,  742,
- /*   220 */   851,  631,  631,  631,  631,  631,  631,  631,  631,  631,
- /*   230 */   631,  631,  631,  631,  631,  631,  704,  631,  655,  653,
- /*   240 */   631,  647,  631,
+ /*     0 */   635,  687,  676,  855,  855,  635,  635,  635,  635,  635,
+ /*    10 */   635,  783,  653,  855,  635,  635,  635,  635,  635,  635,
+ /*    20 */   635,  635,  635,  689,  689,  689,  778,  635,  635,  635,
+ /*    30 */   635,  635,  635,  635,  635,  635,  635,  635,  635,  635,
+ /*    40 */   635,  635,  635,  635,  635,  635,  635,  635,  635,  635,
+ /*    50 */   635,  635,  635,  635,  635,  635,  635,  785,  787,  635,
+ /*    60 */   804,  804,  776,  635,  635,  635,  635,  635,  635,  635,
+ /*    70 */   635,  635,  635,  635,  635,  635,  635,  635,  635,  635,
+ /*    80 */   635,  674,  635,  672,  635,  635,  635,  635,  635,  635,
+ /*    90 */   635,  635,  635,  635,  635,  635,  635,  661,  635,  635,
+ /*   100 */   635,  655,  655,  635,  635,  655,  811,  815,  809,  797,
+ /*   110 */   805,  796,  792,  791,  819,  635,  655,  655,  684,  684,
+ /*   120 */   655,  705,  703,  701,  693,  699,  695,  697,  691,  655,
+ /*   130 */   682,  655,  682,  722,  737,  635,  820,  854,  810,  838,
+ /*   140 */   837,  850,  844,  843,  635,  842,  841,  840,  839,  635,
+ /*   150 */   635,  635,  635,  846,  845,  635,  635,  635,  635,  635,
+ /*   160 */   635,  635,  635,  635,  822,  816,  812,  635,  635,  635,
+ /*   170 */   635,  635,  635,  635,  635,  635,  635,  635,  635,  635,
+ /*   180 */   635,  635,  635,  635,  775,  635,  635,  784,  635,  635,
+ /*   190 */   635,  635,  635,  635,  806,  635,  798,  635,  635,  635,
+ /*   200 */   635,  635,  635,  752,  635,  635,  635,  635,  635,  635,
+ /*   210 */   635,  635,  635,  635,  635,  635,  635,  859,  635,  635,
+ /*   220 */   635,  746,  857,  635,  635,  635,  635,  635,  635,  635,
+ /*   230 */   635,  635,  635,  635,  635,  635,  635,  635,  708,  635,
+ /*   240 */   659,  657,  635,  651,  635,
 };
 /********** End of lemon-generated parsing tables *****************************/
 
@@ -1154,84 +1155,86 @@ static const char *const yyRuleName[] = {
  /* 145 */ "as ::=",
  /* 146 */ "from ::= FROM tablelist",
  /* 147 */ "tablelist ::= ids cpxName",
- /* 148 */ "tablelist ::= tablelist COMMA ids cpxName",
- /* 149 */ "tmvar ::= VARIABLE",
- /* 150 */ "interval_opt ::= INTERVAL LP tmvar RP",
- /* 151 */ "interval_opt ::=",
- /* 152 */ "fill_opt ::=",
- /* 153 */ "fill_opt ::= FILL LP ID COMMA tagitemlist RP",
- /* 154 */ "fill_opt ::= FILL LP ID RP",
- /* 155 */ "sliding_opt ::= SLIDING LP tmvar RP",
- /* 156 */ "sliding_opt ::=",
- /* 157 */ "orderby_opt ::=",
- /* 158 */ "orderby_opt ::= ORDER BY sortlist",
- /* 159 */ "sortlist ::= sortlist COMMA item sortorder",
- /* 160 */ "sortlist ::= item sortorder",
- /* 161 */ "item ::= ids cpxName",
- /* 162 */ "sortorder ::= ASC",
- /* 163 */ "sortorder ::= DESC",
- /* 164 */ "sortorder ::=",
- /* 165 */ "groupby_opt ::=",
- /* 166 */ "groupby_opt ::= GROUP BY grouplist",
- /* 167 */ "grouplist ::= grouplist COMMA item",
- /* 168 */ "grouplist ::= item",
- /* 169 */ "having_opt ::=",
- /* 170 */ "having_opt ::= HAVING expr",
- /* 171 */ "limit_opt ::=",
- /* 172 */ "limit_opt ::= LIMIT signed",
- /* 173 */ "limit_opt ::= LIMIT signed OFFSET signed",
- /* 174 */ "limit_opt ::= LIMIT signed COMMA signed",
- /* 175 */ "slimit_opt ::=",
- /* 176 */ "slimit_opt ::= SLIMIT signed",
- /* 177 */ "slimit_opt ::= SLIMIT signed SOFFSET signed",
- /* 178 */ "slimit_opt ::= SLIMIT signed COMMA signed",
- /* 179 */ "where_opt ::=",
- /* 180 */ "where_opt ::= WHERE expr",
- /* 181 */ "expr ::= LP expr RP",
- /* 182 */ "expr ::= ID",
- /* 183 */ "expr ::= ID DOT ID",
- /* 184 */ "expr ::= ID DOT STAR",
- /* 185 */ "expr ::= INTEGER",
- /* 186 */ "expr ::= MINUS INTEGER",
- /* 187 */ "expr ::= PLUS INTEGER",
- /* 188 */ "expr ::= FLOAT",
- /* 189 */ "expr ::= MINUS FLOAT",
- /* 190 */ "expr ::= PLUS FLOAT",
- /* 191 */ "expr ::= STRING",
- /* 192 */ "expr ::= NOW",
- /* 193 */ "expr ::= VARIABLE",
- /* 194 */ "expr ::= BOOL",
- /* 195 */ "expr ::= ID LP exprlist RP",
- /* 196 */ "expr ::= ID LP STAR RP",
- /* 197 */ "expr ::= expr AND expr",
- /* 198 */ "expr ::= expr OR expr",
- /* 199 */ "expr ::= expr LT expr",
- /* 200 */ "expr ::= expr GT expr",
- /* 201 */ "expr ::= expr LE expr",
- /* 202 */ "expr ::= expr GE expr",
- /* 203 */ "expr ::= expr NE expr",
- /* 204 */ "expr ::= expr EQ expr",
- /* 205 */ "expr ::= expr PLUS expr",
- /* 206 */ "expr ::= expr MINUS expr",
- /* 207 */ "expr ::= expr STAR expr",
- /* 208 */ "expr ::= expr SLASH expr",
- /* 209 */ "expr ::= expr REM expr",
- /* 210 */ "expr ::= expr LIKE expr",
- /* 211 */ "expr ::= expr IN LP exprlist RP",
- /* 212 */ "exprlist ::= exprlist COMMA expritem",
- /* 213 */ "exprlist ::= expritem",
- /* 214 */ "expritem ::= expr",
- /* 215 */ "expritem ::=",
- /* 216 */ "cmd ::= RESET QUERY CACHE",
- /* 217 */ "cmd ::= ALTER TABLE ids cpxName ADD COLUMN columnlist",
- /* 218 */ "cmd ::= ALTER TABLE ids cpxName DROP COLUMN ids",
- /* 219 */ "cmd ::= ALTER TABLE ids cpxName ADD TAG columnlist",
- /* 220 */ "cmd ::= ALTER TABLE ids cpxName DROP TAG ids",
- /* 221 */ "cmd ::= ALTER TABLE ids cpxName CHANGE TAG ids ids",
- /* 222 */ "cmd ::= ALTER TABLE ids cpxName SET TAG ids EQ tagitem",
- /* 223 */ "cmd ::= KILL CONNECTION INTEGER",
- /* 224 */ "cmd ::= KILL STREAM INTEGER COLON INTEGER",
- /* 225 */ "cmd ::= KILL QUERY INTEGER COLON INTEGER",
+ /* 148 */ "tablelist ::= ids cpxName ids",
+ /* 149 */ "tablelist ::= tablelist COMMA ids cpxName",
+ /* 150 */ "tablelist ::= tablelist COMMA ids cpxName ids",
+ /* 151 */ "tmvar ::= VARIABLE",
+ /* 152 */ "interval_opt ::= INTERVAL LP tmvar RP",
+ /* 153 */ "interval_opt ::=",
+ /* 154 */ "fill_opt ::=",
+ /* 155 */ "fill_opt ::= FILL LP ID COMMA tagitemlist RP",
+ /* 156 */ "fill_opt ::= FILL LP ID RP",
+ /* 157 */ "sliding_opt ::= SLIDING LP tmvar RP",
+ /* 158 */ "sliding_opt ::=",
+ /* 159 */ "orderby_opt ::=",
+ /* 160 */ "orderby_opt ::= ORDER BY sortlist",
+ /* 161 */ "sortlist ::= sortlist COMMA item sortorder",
+ /* 162 */ "sortlist ::= item sortorder",
+ /* 163 */ "item ::= ids cpxName",
+ /* 164 */ "sortorder ::= ASC",
+ /* 165 */ "sortorder ::= DESC",
+ /* 166 */ "sortorder ::=",
+ /* 167 */ "groupby_opt ::=",
+ /* 168 */ "groupby_opt ::= GROUP BY grouplist",
+ /* 169 */ "grouplist ::= grouplist COMMA item",
+ /* 170 */ "grouplist ::= item",
+ /* 171 */ "having_opt ::=",
+ /* 172 */ "having_opt ::= HAVING expr",
+ /* 173 */ "limit_opt ::=",
+ /* 174 */ "limit_opt ::= LIMIT signed",
+ /* 175 */ "limit_opt ::= LIMIT signed OFFSET signed",
+ /* 176 */ "limit_opt ::= LIMIT signed COMMA signed",
+ /* 177 */ "slimit_opt ::=",
+ /* 178 */ "slimit_opt ::= SLIMIT signed",
+ /* 179 */ "slimit_opt ::= SLIMIT signed SOFFSET signed",
+ /* 180 */ "slimit_opt ::= SLIMIT signed COMMA signed",
+ /* 181 */ "where_opt ::=",
+ /* 182 */ "where_opt ::= WHERE expr",
+ /* 183 */ "expr ::= LP expr RP",
+ /* 184 */ "expr ::= ID",
+ /* 185 */ "expr ::= ID DOT ID",
+ /* 186 */ "expr ::= ID DOT STAR",
+ /* 187 */ "expr ::= INTEGER",
+ /* 188 */ "expr ::= MINUS INTEGER",
+ /* 189 */ "expr ::= PLUS INTEGER",
+ /* 190 */ "expr ::= FLOAT",
+ /* 191 */ "expr ::= MINUS FLOAT",
+ /* 192 */ "expr ::= PLUS FLOAT",
+ /* 193 */ "expr ::= STRING",
+ /* 194 */ "expr ::= NOW",
+ /* 195 */ "expr ::= VARIABLE",
+ /* 196 */ "expr ::= BOOL",
+ /* 197 */ "expr ::= ID LP exprlist RP",
+ /* 198 */ "expr ::= ID LP STAR RP",
+ /* 199 */ "expr ::= expr AND expr",
+ /* 200 */ "expr ::= expr OR expr",
+ /* 201 */ "expr ::= expr LT expr",
+ /* 202 */ "expr ::= expr GT expr",
+ /* 203 */ "expr ::= expr LE expr",
+ /* 204 */ "expr ::= expr GE expr",
+ /* 205 */ "expr ::= expr NE expr",
+ /* 206 */ "expr ::= expr EQ expr",
+ /* 207 */ "expr ::= expr PLUS expr",
+ /* 208 */ "expr ::= expr MINUS expr",
+ /* 209 */ "expr ::= expr STAR expr",
+ /* 210 */ "expr ::= expr SLASH expr",
+ /* 211 */ "expr ::= expr REM expr",
+ /* 212 */ "expr ::= expr LIKE expr",
+ /* 213 */ "expr ::= expr IN LP exprlist RP",
+ /* 214 */ "exprlist ::= exprlist COMMA expritem",
+ /* 215 */ "exprlist ::= expritem",
+ /* 216 */ "expritem ::= expr",
+ /* 217 */ "expritem ::=",
+ /* 218 */ "cmd ::= RESET QUERY CACHE",
+ /* 219 */ "cmd ::= ALTER TABLE ids cpxName ADD COLUMN columnlist",
+ /* 220 */ "cmd ::= ALTER TABLE ids cpxName DROP COLUMN ids",
+ /* 221 */ "cmd ::= ALTER TABLE ids cpxName ADD TAG columnlist",
+ /* 222 */ "cmd ::= ALTER TABLE ids cpxName DROP TAG ids",
+ /* 223 */ "cmd ::= ALTER TABLE ids cpxName CHANGE TAG ids ids",
+ /* 224 */ "cmd ::= ALTER TABLE ids cpxName SET TAG ids EQ tagitem",
+ /* 225 */ "cmd ::= KILL CONNECTION INTEGER",
+ /* 226 */ "cmd ::= KILL STREAM INTEGER COLON INTEGER",
+ /* 227 */ "cmd ::= KILL QUERY INTEGER COLON INTEGER",
 };
 #endif /* NDEBUG */
 
@@ -1837,84 +1840,86 @@ static const struct {
   {  263,    0 }, /* (145) as ::= */
   {  250,   -2 }, /* (146) from ::= FROM tablelist */
   {  264,   -2 }, /* (147) tablelist ::= ids cpxName */
-  {  264,   -4 }, /* (148) tablelist ::= tablelist COMMA ids cpxName */
-  {  265,   -1 }, /* (149) tmvar ::= VARIABLE */
-  {  252,   -4 }, /* (150) interval_opt ::= INTERVAL LP tmvar RP */
-  {  252,    0 }, /* (151) interval_opt ::= */
-  {  253,    0 }, /* (152) fill_opt ::= */
-  {  253,   -6 }, /* (153) fill_opt ::= FILL LP ID COMMA tagitemlist RP */
-  {  253,   -4 }, /* (154) fill_opt ::= FILL LP ID RP */
-  {  254,   -4 }, /* (155) sliding_opt ::= SLIDING LP tmvar RP */
-  {  254,    0 }, /* (156) sliding_opt ::= */
-  {  256,    0 }, /* (157) orderby_opt ::= */
-  {  256,   -3 }, /* (158) orderby_opt ::= ORDER BY sortlist */
-  {  266,   -4 }, /* (159) sortlist ::= sortlist COMMA item sortorder */
-  {  266,   -2 }, /* (160) sortlist ::= item sortorder */
-  {  268,   -2 }, /* (161) item ::= ids cpxName */
-  {  269,   -1 }, /* (162) sortorder ::= ASC */
-  {  269,   -1 }, /* (163) sortorder ::= DESC */
-  {  269,    0 }, /* (164) sortorder ::= */
-  {  255,    0 }, /* (165) groupby_opt ::= */
-  {  255,   -3 }, /* (166) groupby_opt ::= GROUP BY grouplist */
-  {  270,   -3 }, /* (167) grouplist ::= grouplist COMMA item */
-  {  270,   -1 }, /* (168) grouplist ::= item */
-  {  257,    0 }, /* (169) having_opt ::= */
-  {  257,   -2 }, /* (170) having_opt ::= HAVING expr */
-  {  259,    0 }, /* (171) limit_opt ::= */
-  {  259,   -2 }, /* (172) limit_opt ::= LIMIT signed */
-  {  259,   -4 }, /* (173) limit_opt ::= LIMIT signed OFFSET signed */
-  {  259,   -4 }, /* (174) limit_opt ::= LIMIT signed COMMA signed */
-  {  258,    0 }, /* (175) slimit_opt ::= */
-  {  258,   -2 }, /* (176) slimit_opt ::= SLIMIT signed */
-  {  258,   -4 }, /* (177) slimit_opt ::= SLIMIT signed SOFFSET signed */
-  {  258,   -4 }, /* (178) slimit_opt ::= SLIMIT signed COMMA signed */
-  {  251,    0 }, /* (179) where_opt ::= */
-  {  251,   -2 }, /* (180) where_opt ::= WHERE expr */
-  {  262,   -3 }, /* (181) expr ::= LP expr RP */
-  {  262,   -1 }, /* (182) expr ::= ID */
-  {  262,   -3 }, /* (183) expr ::= ID DOT ID */
-  {  262,   -3 }, /* (184) expr ::= ID DOT STAR */
-  {  262,   -1 }, /* (185) expr ::= INTEGER */
-  {  262,   -2 }, /* (186) expr ::= MINUS INTEGER */
-  {  262,   -2 }, /* (187) expr ::= PLUS INTEGER */
-  {  262,   -1 }, /* (188) expr ::= FLOAT */
-  {  262,   -2 }, /* (189) expr ::= MINUS FLOAT */
-  {  262,   -2 }, /* (190) expr ::= PLUS FLOAT */
-  {  262,   -1 }, /* (191) expr ::= STRING */
-  {  262,   -1 }, /* (192) expr ::= NOW */
-  {  262,   -1 }, /* (193) expr ::= VARIABLE */
-  {  262,   -1 }, /* (194) expr ::= BOOL */
-  {  262,   -4 }, /* (195) expr ::= ID LP exprlist RP */
-  {  262,   -4 }, /* (196) expr ::= ID LP STAR RP */
-  {  262,   -3 }, /* (197) expr ::= expr AND expr */
-  {  262,   -3 }, /* (198) expr ::= expr OR expr */
-  {  262,   -3 }, /* (199) expr ::= expr LT expr */
-  {  262,   -3 }, /* (200) expr ::= expr GT expr */
-  {  262,   -3 }, /* (201) expr ::= expr LE expr */
-  {  262,   -3 }, /* (202) expr ::= expr GE expr */
-  {  262,   -3 }, /* (203) expr ::= expr NE expr */
-  {  262,   -3 }, /* (204) expr ::= expr EQ expr */
-  {  262,   -3 }, /* (205) expr ::= expr PLUS expr */
-  {  262,   -3 }, /* (206) expr ::= expr MINUS expr */
-  {  262,   -3 }, /* (207) expr ::= expr STAR expr */
-  {  262,   -3 }, /* (208) expr ::= expr SLASH expr */
-  {  262,   -3 }, /* (209) expr ::= expr REM expr */
-  {  262,   -3 }, /* (210) expr ::= expr LIKE expr */
-  {  262,   -5 }, /* (211) expr ::= expr IN LP exprlist RP */
-  {  271,   -3 }, /* (212) exprlist ::= exprlist COMMA expritem */
-  {  271,   -1 }, /* (213) exprlist ::= expritem */
-  {  272,   -1 }, /* (214) expritem ::= expr */
-  {  272,    0 }, /* (215) expritem ::= */
-  {  209,   -3 }, /* (216) cmd ::= RESET QUERY CACHE */
-  {  209,   -7 }, /* (217) cmd ::= ALTER TABLE ids cpxName ADD COLUMN columnlist */
-  {  209,   -7 }, /* (218) cmd ::= ALTER TABLE ids cpxName DROP COLUMN ids */
-  {  209,   -7 }, /* (219) cmd ::= ALTER TABLE ids cpxName ADD TAG columnlist */
-  {  209,   -7 }, /* (220) cmd ::= ALTER TABLE ids cpxName DROP TAG ids */
-  {  209,   -8 }, /* (221) cmd ::= ALTER TABLE ids cpxName CHANGE TAG ids ids */
-  {  209,   -9 }, /* (222) cmd ::= ALTER TABLE ids cpxName SET TAG ids EQ tagitem */
-  {  209,   -3 }, /* (223) cmd ::= KILL CONNECTION INTEGER */
-  {  209,   -5 }, /* (224) cmd ::= KILL STREAM INTEGER COLON INTEGER */
-  {  209,   -5 }, /* (225) cmd ::= KILL QUERY INTEGER COLON INTEGER */
+  {  264,   -3 }, /* (148) tablelist ::= ids cpxName ids */
+  {  264,   -4 }, /* (149) tablelist ::= tablelist COMMA ids cpxName */
+  {  264,   -5 }, /* (150) tablelist ::= tablelist COMMA ids cpxName ids */
+  {  265,   -1 }, /* (151) tmvar ::= VARIABLE */
+  {  252,   -4 }, /* (152) interval_opt ::= INTERVAL LP tmvar RP */
+  {  252,    0 }, /* (153) interval_opt ::= */
+  {  253,    0 }, /* (154) fill_opt ::= */
+  {  253,   -6 }, /* (155) fill_opt ::= FILL LP ID COMMA tagitemlist RP */
+  {  253,   -4 }, /* (156) fill_opt ::= FILL LP ID RP */
+  {  254,   -4 }, /* (157) sliding_opt ::= SLIDING LP tmvar RP */
+  {  254,    0 }, /* (158) sliding_opt ::= */
+  {  256,    0 }, /* (159) orderby_opt ::= */
+  {  256,   -3 }, /* (160) orderby_opt ::= ORDER BY sortlist */
+  {  266,   -4 }, /* (161) sortlist ::= sortlist COMMA item sortorder */
+  {  266,   -2 }, /* (162) sortlist ::= item sortorder */
+  {  268,   -2 }, /* (163) item ::= ids cpxName */
+  {  269,   -1 }, /* (164) sortorder ::= ASC */
+  {  269,   -1 }, /* (165) sortorder ::= DESC */
+  {  269,    0 }, /* (166) sortorder ::= */
+  {  255,    0 }, /* (167) groupby_opt ::= */
+  {  255,   -3 }, /* (168) groupby_opt ::= GROUP BY grouplist */
+  {  270,   -3 }, /* (169) grouplist ::= grouplist COMMA item */
+  {  270,   -1 }, /* (170) grouplist ::= item */
+  {  257,    0 }, /* (171) having_opt ::= */
+  {  257,   -2 }, /* (172) having_opt ::= HAVING expr */
+  {  259,    0 }, /* (173) limit_opt ::= */
+  {  259,   -2 }, /* (174) limit_opt ::= LIMIT signed */
+  {  259,   -4 }, /* (175) limit_opt ::= LIMIT signed OFFSET signed */
+  {  259,   -4 }, /* (176) limit_opt ::= LIMIT signed COMMA signed */
+  {  258,    0 }, /* (177) slimit_opt ::= */
+  {  258,   -2 }, /* (178) slimit_opt ::= SLIMIT signed */
+  {  258,   -4 }, /* (179) slimit_opt ::= SLIMIT signed SOFFSET signed */
+  {  258,   -4 }, /* (180) slimit_opt ::= SLIMIT signed COMMA signed */
+  {  251,    0 }, /* (181) where_opt ::= */
+  {  251,   -2 }, /* (182) where_opt ::= WHERE expr */
+  {  262,   -3 }, /* (183) expr ::= LP expr RP */
+  {  262,   -1 }, /* (184) expr ::= ID */
+  {  262,   -3 }, /* (185) expr ::= ID DOT ID */
+  {  262,   -3 }, /* (186) expr ::= ID DOT STAR */
+  {  262,   -1 }, /* (187) expr ::= INTEGER */
+  {  262,   -2 }, /* (188) expr ::= MINUS INTEGER */
+  {  262,   -2 }, /* (189) expr ::= PLUS INTEGER */
+  {  262,   -1 }, /* (190) expr ::= FLOAT */
+  {  262,   -2 }, /* (191) expr ::= MINUS FLOAT */
+  {  262,   -2 }, /* (192) expr ::= PLUS FLOAT */
+  {  262,   -1 }, /* (193) expr ::= STRING */
+  {  262,   -1 }, /* (194) expr ::= NOW */
+  {  262,   -1 }, /* (195) expr ::= VARIABLE */
+  {  262,   -1 }, /* (196) expr ::= BOOL */
+  {  262,   -4 }, /* (197) expr ::= ID LP exprlist RP */
+  {  262,   -4 }, /* (198) expr ::= ID LP STAR RP */
+  {  262,   -3 }, /* (199) expr ::= expr AND expr */
+  {  262,   -3 }, /* (200) expr ::= expr OR expr */
+  {  262,   -3 }, /* (201) expr ::= expr LT expr */
+  {  262,   -3 }, /* (202) expr ::= expr GT expr */
+  {  262,   -3 }, /* (203) expr ::= expr LE expr */
+  {  262,   -3 }, /* (204) expr ::= expr GE expr */
+  {  262,   -3 }, /* (205) expr ::= expr NE expr */
+  {  262,   -3 }, /* (206) expr ::= expr EQ expr */
+  {  262,   -3 }, /* (207) expr ::= expr PLUS expr */
+  {  262,   -3 }, /* (208) expr ::= expr MINUS expr */
+  {  262,   -3 }, /* (209) expr ::= expr STAR expr */
+  {  262,   -3 }, /* (210) expr ::= expr SLASH expr */
+  {  262,   -3 }, /* (211) expr ::= expr REM expr */
+  {  262,   -3 }, /* (212) expr ::= expr LIKE expr */
+  {  262,   -5 }, /* (213) expr ::= expr IN LP exprlist RP */
+  {  271,   -3 }, /* (214) exprlist ::= exprlist COMMA expritem */
+  {  271,   -1 }, /* (215) exprlist ::= expritem */
+  {  272,   -1 }, /* (216) expritem ::= expr */
+  {  272,    0 }, /* (217) expritem ::= */
+  {  209,   -3 }, /* (218) cmd ::= RESET QUERY CACHE */
+  {  209,   -7 }, /* (219) cmd ::= ALTER TABLE ids cpxName ADD COLUMN columnlist */
+  {  209,   -7 }, /* (220) cmd ::= ALTER TABLE ids cpxName DROP COLUMN ids */
+  {  209,   -7 }, /* (221) cmd ::= ALTER TABLE ids cpxName ADD TAG columnlist */
+  {  209,   -7 }, /* (222) cmd ::= ALTER TABLE ids cpxName DROP TAG ids */
+  {  209,   -8 }, /* (223) cmd ::= ALTER TABLE ids cpxName CHANGE TAG ids ids */
+  {  209,   -9 }, /* (224) cmd ::= ALTER TABLE ids cpxName SET TAG ids EQ tagitem */
+  {  209,   -3 }, /* (225) cmd ::= KILL CONNECTION INTEGER */
+  {  209,   -5 }, /* (226) cmd ::= KILL STREAM INTEGER COLON INTEGER */
+  {  209,   -5 }, /* (227) cmd ::= KILL QUERY INTEGER COLON INTEGER */
 };
 
 static void yy_accept(yyParser*);  /* Forward Declaration */
@@ -2465,29 +2470,59 @@ static void yy_reduce(
 {yymsp[-1].minor.yy498 = yymsp[0].minor.yy498;}
         break;
       case 147: /* tablelist ::= ids cpxName */
-{ toTSDBType(yymsp[-1].minor.yy0.type); yymsp[-1].minor.yy0.n += yymsp[0].minor.yy0.n; yylhsminor.yy498 = tVariantListAppendToken(NULL, &yymsp[-1].minor.yy0, -1);}
+{
+  toTSDBType(yymsp[-1].minor.yy0.type);
+  yymsp[-1].minor.yy0.n += yymsp[0].minor.yy0.n;
+  yylhsminor.yy498 = tVariantListAppendToken(NULL, &yymsp[-1].minor.yy0, -1);
+  yylhsminor.yy498 = tVariantListAppendToken(yylhsminor.yy498, &yymsp[-1].minor.yy0, -1);  // table alias name
+}
   yymsp[-1].minor.yy498 = yylhsminor.yy498;
         break;
-      case 148: /* tablelist ::= tablelist COMMA ids cpxName */
-{ toTSDBType(yymsp[-1].minor.yy0.type); yymsp[-1].minor.yy0.n += yymsp[0].minor.yy0.n; yylhsminor.yy498 = tVariantListAppendToken(yymsp[-3].minor.yy498, &yymsp[-1].minor.yy0, -1);   }
+      case 148: /* tablelist ::= ids cpxName ids */
+{
+   toTSDBType(yymsp[-2].minor.yy0.type);
+   toTSDBType(yymsp[0].minor.yy0.type);
+   yymsp[-2].minor.yy0.n += yymsp[-1].minor.yy0.n;
+   yylhsminor.yy498 = tVariantListAppendToken(NULL, &yymsp[-2].minor.yy0, -1);
+   yylhsminor.yy498 = tVariantListAppendToken(yylhsminor.yy498, &yymsp[0].minor.yy0, -1);
+}
+  yymsp[-2].minor.yy498 = yylhsminor.yy498;
+        break;
+      case 149: /* tablelist ::= tablelist COMMA ids cpxName */
+{
+  toTSDBType(yymsp[-1].minor.yy0.type);
+  yymsp[-1].minor.yy0.n += yymsp[0].minor.yy0.n;
+  yylhsminor.yy498 = tVariantListAppendToken(yymsp[-3].minor.yy498, &yymsp[-1].minor.yy0, -1);
+  yylhsminor.yy498 = tVariantListAppendToken(yylhsminor.yy498, &yymsp[-1].minor.yy0, -1);
+}
   yymsp[-3].minor.yy498 = yylhsminor.yy498;
         break;
-      case 149: /* tmvar ::= VARIABLE */
+      case 150: /* tablelist ::= tablelist COMMA ids cpxName ids */
+{
+   toTSDBType(yymsp[-2].minor.yy0.type);
+   toTSDBType(yymsp[0].minor.yy0.type);
+   yymsp[-2].minor.yy0.n += yymsp[-1].minor.yy0.n;
+   yylhsminor.yy498 = tVariantListAppendToken(yymsp[-4].minor.yy498, &yymsp[-2].minor.yy0, -1);
+   yylhsminor.yy498 = tVariantListAppendToken(yylhsminor.yy498, &yymsp[0].minor.yy0, -1);
+}
+  yymsp[-4].minor.yy498 = yylhsminor.yy498;
+        break;
+      case 151: /* tmvar ::= VARIABLE */
 {yylhsminor.yy0 = yymsp[0].minor.yy0;}
   yymsp[0].minor.yy0 = yylhsminor.yy0;
         break;
-      case 150: /* interval_opt ::= INTERVAL LP tmvar RP */
-      case 155: /* sliding_opt ::= SLIDING LP tmvar RP */ yytestcase(yyruleno==155);
+      case 152: /* interval_opt ::= INTERVAL LP tmvar RP */
+      case 157: /* sliding_opt ::= SLIDING LP tmvar RP */ yytestcase(yyruleno==157);
 {yymsp[-3].minor.yy0 = yymsp[-1].minor.yy0;     }
         break;
-      case 151: /* interval_opt ::= */
-      case 156: /* sliding_opt ::= */ yytestcase(yyruleno==156);
+      case 153: /* interval_opt ::= */
+      case 158: /* sliding_opt ::= */ yytestcase(yyruleno==158);
 {yymsp[1].minor.yy0.n = 0; yymsp[1].minor.yy0.z = NULL; yymsp[1].minor.yy0.type = 0;   }
         break;
-      case 152: /* fill_opt ::= */
+      case 154: /* fill_opt ::= */
 {yymsp[1].minor.yy498 = 0;     }
         break;
-      case 153: /* fill_opt ::= FILL LP ID COMMA tagitemlist RP */
+      case 155: /* fill_opt ::= FILL LP ID COMMA tagitemlist RP */
 {
     tVariant A = {0};
     toTSDBType(yymsp[-3].minor.yy0.type);
@@ -2497,33 +2532,33 @@ static void yy_reduce(
     yymsp[-5].minor.yy498 = yymsp[-1].minor.yy498;
 }
         break;
-      case 154: /* fill_opt ::= FILL LP ID RP */
+      case 156: /* fill_opt ::= FILL LP ID RP */
 {
     toTSDBType(yymsp[-1].minor.yy0.type);
     yymsp[-3].minor.yy498 = tVariantListAppendToken(NULL, &yymsp[-1].minor.yy0, -1);
 }
         break;
-      case 157: /* orderby_opt ::= */
-      case 165: /* groupby_opt ::= */ yytestcase(yyruleno==165);
+      case 159: /* orderby_opt ::= */
+      case 167: /* groupby_opt ::= */ yytestcase(yyruleno==167);
 {yymsp[1].minor.yy498 = 0;}
         break;
-      case 158: /* orderby_opt ::= ORDER BY sortlist */
-      case 166: /* groupby_opt ::= GROUP BY grouplist */ yytestcase(yyruleno==166);
+      case 160: /* orderby_opt ::= ORDER BY sortlist */
+      case 168: /* groupby_opt ::= GROUP BY grouplist */ yytestcase(yyruleno==168);
 {yymsp[-2].minor.yy498 = yymsp[0].minor.yy498;}
         break;
-      case 159: /* sortlist ::= sortlist COMMA item sortorder */
+      case 161: /* sortlist ::= sortlist COMMA item sortorder */
 {
     yylhsminor.yy498 = tVariantListAppend(yymsp[-3].minor.yy498, &yymsp[-1].minor.yy134, yymsp[0].minor.yy46);
 }
   yymsp[-3].minor.yy498 = yylhsminor.yy498;
         break;
-      case 160: /* sortlist ::= item sortorder */
+      case 162: /* sortlist ::= item sortorder */
 {
   yylhsminor.yy498 = tVariantListAppend(NULL, &yymsp[-1].minor.yy134, yymsp[0].minor.yy46);
 }
   yymsp[-1].minor.yy498 = yylhsminor.yy498;
         break;
-      case 161: /* item ::= ids cpxName */
+      case 163: /* item ::= ids cpxName */
 {
   toTSDBType(yymsp[-1].minor.yy0.type);
   yymsp[-1].minor.yy0.n += yymsp[0].minor.yy0.n;
@@ -2532,196 +2567,196 @@ static void yy_reduce(
 }
   yymsp[-1].minor.yy134 = yylhsminor.yy134;
         break;
-      case 162: /* sortorder ::= ASC */
+      case 164: /* sortorder ::= ASC */
 {yymsp[0].minor.yy46 = TSDB_ORDER_ASC; }
         break;
-      case 163: /* sortorder ::= DESC */
+      case 165: /* sortorder ::= DESC */
 {yymsp[0].minor.yy46 = TSDB_ORDER_DESC;}
         break;
-      case 164: /* sortorder ::= */
+      case 166: /* sortorder ::= */
 {yymsp[1].minor.yy46 = TSDB_ORDER_ASC;}
         break;
-      case 167: /* grouplist ::= grouplist COMMA item */
+      case 169: /* grouplist ::= grouplist COMMA item */
 {
   yylhsminor.yy498 = tVariantListAppend(yymsp[-2].minor.yy498, &yymsp[0].minor.yy134, -1);
 }
   yymsp[-2].minor.yy498 = yylhsminor.yy498;
         break;
-      case 168: /* grouplist ::= item */
+      case 170: /* grouplist ::= item */
 {
   yylhsminor.yy498 = tVariantListAppend(NULL, &yymsp[0].minor.yy134, -1);
 }
   yymsp[0].minor.yy498 = yylhsminor.yy498;
         break;
-      case 169: /* having_opt ::= */
-      case 179: /* where_opt ::= */ yytestcase(yyruleno==179);
-      case 215: /* expritem ::= */ yytestcase(yyruleno==215);
+      case 171: /* having_opt ::= */
+      case 181: /* where_opt ::= */ yytestcase(yyruleno==181);
+      case 217: /* expritem ::= */ yytestcase(yyruleno==217);
 {yymsp[1].minor.yy64 = 0;}
         break;
-      case 170: /* having_opt ::= HAVING expr */
-      case 180: /* where_opt ::= WHERE expr */ yytestcase(yyruleno==180);
+      case 172: /* having_opt ::= HAVING expr */
+      case 182: /* where_opt ::= WHERE expr */ yytestcase(yyruleno==182);
 {yymsp[-1].minor.yy64 = yymsp[0].minor.yy64;}
         break;
-      case 171: /* limit_opt ::= */
-      case 175: /* slimit_opt ::= */ yytestcase(yyruleno==175);
+      case 173: /* limit_opt ::= */
+      case 177: /* slimit_opt ::= */ yytestcase(yyruleno==177);
 {yymsp[1].minor.yy216.limit = -1; yymsp[1].minor.yy216.offset = 0;}
         break;
-      case 172: /* limit_opt ::= LIMIT signed */
-      case 176: /* slimit_opt ::= SLIMIT signed */ yytestcase(yyruleno==176);
+      case 174: /* limit_opt ::= LIMIT signed */
+      case 178: /* slimit_opt ::= SLIMIT signed */ yytestcase(yyruleno==178);
 {yymsp[-1].minor.yy216.limit = yymsp[0].minor.yy207;  yymsp[-1].minor.yy216.offset = 0;}
         break;
-      case 173: /* limit_opt ::= LIMIT signed OFFSET signed */
-      case 177: /* slimit_opt ::= SLIMIT signed SOFFSET signed */ yytestcase(yyruleno==177);
+      case 175: /* limit_opt ::= LIMIT signed OFFSET signed */
+      case 179: /* slimit_opt ::= SLIMIT signed SOFFSET signed */ yytestcase(yyruleno==179);
 {yymsp[-3].minor.yy216.limit = yymsp[-2].minor.yy207;  yymsp[-3].minor.yy216.offset = yymsp[0].minor.yy207;}
         break;
-      case 174: /* limit_opt ::= LIMIT signed COMMA signed */
-      case 178: /* slimit_opt ::= SLIMIT signed COMMA signed */ yytestcase(yyruleno==178);
+      case 176: /* limit_opt ::= LIMIT signed COMMA signed */
+      case 180: /* slimit_opt ::= SLIMIT signed COMMA signed */ yytestcase(yyruleno==180);
 {yymsp[-3].minor.yy216.limit = yymsp[0].minor.yy207;  yymsp[-3].minor.yy216.offset = yymsp[-2].minor.yy207;}
         break;
-      case 181: /* expr ::= LP expr RP */
+      case 183: /* expr ::= LP expr RP */
 {yymsp[-2].minor.yy64 = yymsp[-1].minor.yy64; }
         break;
-      case 182: /* expr ::= ID */
+      case 184: /* expr ::= ID */
 {yylhsminor.yy64 = tSQLExprIdValueCreate(&yymsp[0].minor.yy0, TK_ID);}
   yymsp[0].minor.yy64 = yylhsminor.yy64;
         break;
-      case 183: /* expr ::= ID DOT ID */
+      case 185: /* expr ::= ID DOT ID */
 {yymsp[-2].minor.yy0.n += (1+yymsp[0].minor.yy0.n); yylhsminor.yy64 = tSQLExprIdValueCreate(&yymsp[-2].minor.yy0, TK_ID);}
   yymsp[-2].minor.yy64 = yylhsminor.yy64;
         break;
-      case 184: /* expr ::= ID DOT STAR */
+      case 186: /* expr ::= ID DOT STAR */
 {yymsp[-2].minor.yy0.n += (1+yymsp[0].minor.yy0.n); yylhsminor.yy64 = tSQLExprIdValueCreate(&yymsp[-2].minor.yy0, TK_ALL);}
   yymsp[-2].minor.yy64 = yylhsminor.yy64;
         break;
-      case 185: /* expr ::= INTEGER */
+      case 187: /* expr ::= INTEGER */
 {yylhsminor.yy64 = tSQLExprIdValueCreate(&yymsp[0].minor.yy0, TK_INTEGER);}
   yymsp[0].minor.yy64 = yylhsminor.yy64;
         break;
-      case 186: /* expr ::= MINUS INTEGER */
-      case 187: /* expr ::= PLUS INTEGER */ yytestcase(yyruleno==187);
+      case 188: /* expr ::= MINUS INTEGER */
+      case 189: /* expr ::= PLUS INTEGER */ yytestcase(yyruleno==189);
 {yymsp[-1].minor.yy0.n += yymsp[0].minor.yy0.n; yymsp[-1].minor.yy0.type = TK_INTEGER; yylhsminor.yy64 = tSQLExprIdValueCreate(&yymsp[-1].minor.yy0, TK_INTEGER);}
   yymsp[-1].minor.yy64 = yylhsminor.yy64;
         break;
-      case 188: /* expr ::= FLOAT */
+      case 190: /* expr ::= FLOAT */
 {yylhsminor.yy64 = tSQLExprIdValueCreate(&yymsp[0].minor.yy0, TK_FLOAT);}
   yymsp[0].minor.yy64 = yylhsminor.yy64;
         break;
-      case 189: /* expr ::= MINUS FLOAT */
-      case 190: /* expr ::= PLUS FLOAT */ yytestcase(yyruleno==190);
+      case 191: /* expr ::= MINUS FLOAT */
+      case 192: /* expr ::= PLUS FLOAT */ yytestcase(yyruleno==192);
 {yymsp[-1].minor.yy0.n += yymsp[0].minor.yy0.n; yymsp[-1].minor.yy0.type = TK_FLOAT; yylhsminor.yy64 = tSQLExprIdValueCreate(&yymsp[-1].minor.yy0, TK_FLOAT);}
   yymsp[-1].minor.yy64 = yylhsminor.yy64;
         break;
-      case 191: /* expr ::= STRING */
+      case 193: /* expr ::= STRING */
 {yylhsminor.yy64 = tSQLExprIdValueCreate(&yymsp[0].minor.yy0, TK_STRING);}
   yymsp[0].minor.yy64 = yylhsminor.yy64;
         break;
-      case 192: /* expr ::= NOW */
+      case 194: /* expr ::= NOW */
 {yylhsminor.yy64 = tSQLExprIdValueCreate(&yymsp[0].minor.yy0, TK_NOW); }
   yymsp[0].minor.yy64 = yylhsminor.yy64;
         break;
-      case 193: /* expr ::= VARIABLE */
+      case 195: /* expr ::= VARIABLE */
 {yylhsminor.yy64 = tSQLExprIdValueCreate(&yymsp[0].minor.yy0, TK_VARIABLE);}
   yymsp[0].minor.yy64 = yylhsminor.yy64;
         break;
-      case 194: /* expr ::= BOOL */
+      case 196: /* expr ::= BOOL */
 {yylhsminor.yy64 = tSQLExprIdValueCreate(&yymsp[0].minor.yy0, TK_BOOL);}
   yymsp[0].minor.yy64 = yylhsminor.yy64;
         break;
-      case 195: /* expr ::= ID LP exprlist RP */
+      case 197: /* expr ::= ID LP exprlist RP */
 {
   yylhsminor.yy64 = tSQLExprCreateFunction(yymsp[-1].minor.yy290, &yymsp[-3].minor.yy0, &yymsp[0].minor.yy0, yymsp[-3].minor.yy0.type);
 }
   yymsp[-3].minor.yy64 = yylhsminor.yy64;
         break;
-      case 196: /* expr ::= ID LP STAR RP */
+      case 198: /* expr ::= ID LP STAR RP */
 {
   yylhsminor.yy64 = tSQLExprCreateFunction(NULL, &yymsp[-3].minor.yy0, &yymsp[0].minor.yy0, yymsp[-3].minor.yy0.type);
 }
   yymsp[-3].minor.yy64 = yylhsminor.yy64;
         break;
-      case 197: /* expr ::= expr AND expr */
+      case 199: /* expr ::= expr AND expr */
 {yylhsminor.yy64 = tSQLExprCreate(yymsp[-2].minor.yy64, yymsp[0].minor.yy64, TK_AND);}
   yymsp[-2].minor.yy64 = yylhsminor.yy64;
         break;
-      case 198: /* expr ::= expr OR expr */
+      case 200: /* expr ::= expr OR expr */
 {yylhsminor.yy64 = tSQLExprCreate(yymsp[-2].minor.yy64, yymsp[0].minor.yy64, TK_OR); }
   yymsp[-2].minor.yy64 = yylhsminor.yy64;
         break;
-      case 199: /* expr ::= expr LT expr */
+      case 201: /* expr ::= expr LT expr */
 {yylhsminor.yy64 = tSQLExprCreate(yymsp[-2].minor.yy64, yymsp[0].minor.yy64, TK_LT);}
   yymsp[-2].minor.yy64 = yylhsminor.yy64;
         break;
-      case 200: /* expr ::= expr GT expr */
+      case 202: /* expr ::= expr GT expr */
 {yylhsminor.yy64 = tSQLExprCreate(yymsp[-2].minor.yy64, yymsp[0].minor.yy64, TK_GT);}
   yymsp[-2].minor.yy64 = yylhsminor.yy64;
         break;
-      case 201: /* expr ::= expr LE expr */
+      case 203: /* expr ::= expr LE expr */
 {yylhsminor.yy64 = tSQLExprCreate(yymsp[-2].minor.yy64, yymsp[0].minor.yy64, TK_LE);}
   yymsp[-2].minor.yy64 = yylhsminor.yy64;
         break;
-      case 202: /* expr ::= expr GE expr */
+      case 204: /* expr ::= expr GE expr */
 {yylhsminor.yy64 = tSQLExprCreate(yymsp[-2].minor.yy64, yymsp[0].minor.yy64, TK_GE);}
   yymsp[-2].minor.yy64 = yylhsminor.yy64;
         break;
-      case 203: /* expr ::= expr NE expr */
+      case 205: /* expr ::= expr NE expr */
 {yylhsminor.yy64 = tSQLExprCreate(yymsp[-2].minor.yy64, yymsp[0].minor.yy64, TK_NE);}
   yymsp[-2].minor.yy64 = yylhsminor.yy64;
         break;
-      case 204: /* expr ::= expr EQ expr */
+      case 206: /* expr ::= expr EQ expr */
 {yylhsminor.yy64 = tSQLExprCreate(yymsp[-2].minor.yy64, yymsp[0].minor.yy64, TK_EQ);}
   yymsp[-2].minor.yy64 = yylhsminor.yy64;
         break;
-      case 205: /* expr ::= expr PLUS expr */
+      case 207: /* expr ::= expr PLUS expr */
 {yylhsminor.yy64 = tSQLExprCreate(yymsp[-2].minor.yy64, yymsp[0].minor.yy64, TK_PLUS);  }
   yymsp[-2].minor.yy64 = yylhsminor.yy64;
         break;
-      case 206: /* expr ::= expr MINUS expr */
+      case 208: /* expr ::= expr MINUS expr */
 {yylhsminor.yy64 = tSQLExprCreate(yymsp[-2].minor.yy64, yymsp[0].minor.yy64, TK_MINUS); }
   yymsp[-2].minor.yy64 = yylhsminor.yy64;
         break;
-      case 207: /* expr ::= expr STAR expr */
+      case 209: /* expr ::= expr STAR expr */
 {yylhsminor.yy64 = tSQLExprCreate(yymsp[-2].minor.yy64, yymsp[0].minor.yy64, TK_STAR);  }
   yymsp[-2].minor.yy64 = yylhsminor.yy64;
         break;
-      case 208: /* expr ::= expr SLASH expr */
+      case 210: /* expr ::= expr SLASH expr */
 {yylhsminor.yy64 = tSQLExprCreate(yymsp[-2].minor.yy64, yymsp[0].minor.yy64, TK_DIVIDE);}
   yymsp[-2].minor.yy64 = yylhsminor.yy64;
         break;
-      case 209: /* expr ::= expr REM expr */
+      case 211: /* expr ::= expr REM expr */
 {yylhsminor.yy64 = tSQLExprCreate(yymsp[-2].minor.yy64, yymsp[0].minor.yy64, TK_REM);   }
   yymsp[-2].minor.yy64 = yylhsminor.yy64;
         break;
-      case 210: /* expr ::= expr LIKE expr */
+      case 212: /* expr ::= expr LIKE expr */
 {yylhsminor.yy64 = tSQLExprCreate(yymsp[-2].minor.yy64, yymsp[0].minor.yy64, TK_LIKE);  }
   yymsp[-2].minor.yy64 = yylhsminor.yy64;
         break;
-      case 211: /* expr ::= expr IN LP exprlist RP */
+      case 213: /* expr ::= expr IN LP exprlist RP */
 {yylhsminor.yy64 = tSQLExprCreate(yymsp[-4].minor.yy64, (tSQLExpr*)yymsp[-1].minor.yy290, TK_IN); }
   yymsp[-4].minor.yy64 = yylhsminor.yy64;
         break;
-      case 212: /* exprlist ::= exprlist COMMA expritem */
+      case 214: /* exprlist ::= exprlist COMMA expritem */
 {yylhsminor.yy290 = tSQLExprListAppend(yymsp[-2].minor.yy290,yymsp[0].minor.yy64,0);}
   yymsp[-2].minor.yy290 = yylhsminor.yy290;
         break;
-      case 213: /* exprlist ::= expritem */
+      case 215: /* exprlist ::= expritem */
 {yylhsminor.yy290 = tSQLExprListAppend(0,yymsp[0].minor.yy64,0);}
   yymsp[0].minor.yy290 = yylhsminor.yy290;
         break;
-      case 214: /* expritem ::= expr */
+      case 216: /* expritem ::= expr */
 {yylhsminor.yy64 = yymsp[0].minor.yy64;}
   yymsp[0].minor.yy64 = yylhsminor.yy64;
         break;
-      case 216: /* cmd ::= RESET QUERY CACHE */
+      case 218: /* cmd ::= RESET QUERY CACHE */
 { setDCLSQLElems(pInfo, TSDB_SQL_RESET_CACHE, 0);}
         break;
-      case 217: /* cmd ::= ALTER TABLE ids cpxName ADD COLUMN columnlist */
+      case 219: /* cmd ::= ALTER TABLE ids cpxName ADD COLUMN columnlist */
 {
     yymsp[-4].minor.yy0.n += yymsp[-3].minor.yy0.n;
     SAlterTableSQL* pAlterTable = tAlterTableSQLElems(&yymsp[-4].minor.yy0, yymsp[0].minor.yy523, NULL, TSDB_ALTER_TABLE_ADD_COLUMN);
     setSQLInfo(pInfo, pAlterTable, NULL, TSDB_SQL_ALTER_TABLE);
 }
         break;
-      case 218: /* cmd ::= ALTER TABLE ids cpxName DROP COLUMN ids */
+      case 220: /* cmd ::= ALTER TABLE ids cpxName DROP COLUMN ids */
 {
     yymsp[-4].minor.yy0.n += yymsp[-3].minor.yy0.n;
 
@@ -2732,14 +2767,14 @@ static void yy_reduce(
     setSQLInfo(pInfo, pAlterTable, NULL, TSDB_SQL_ALTER_TABLE);
 }
         break;
-      case 219: /* cmd ::= ALTER TABLE ids cpxName ADD TAG columnlist */
+      case 221: /* cmd ::= ALTER TABLE ids cpxName ADD TAG columnlist */
 {
     yymsp[-4].minor.yy0.n += yymsp[-3].minor.yy0.n;
     SAlterTableSQL* pAlterTable = tAlterTableSQLElems(&yymsp[-4].minor.yy0, yymsp[0].minor.yy523, NULL, TSDB_ALTER_TABLE_ADD_TAG_COLUMN);
     setSQLInfo(pInfo, pAlterTable, NULL, TSDB_SQL_ALTER_TABLE);
 }
         break;
-      case 220: /* cmd ::= ALTER TABLE ids cpxName DROP TAG ids */
+      case 222: /* cmd ::= ALTER TABLE ids cpxName DROP TAG ids */
 {
     yymsp[-4].minor.yy0.n += yymsp[-3].minor.yy0.n;
 
@@ -2750,7 +2785,7 @@ static void yy_reduce(
     setSQLInfo(pInfo, pAlterTable, NULL, TSDB_SQL_ALTER_TABLE);
 }
         break;
-      case 221: /* cmd ::= ALTER TABLE ids cpxName CHANGE TAG ids ids */
+      case 223: /* cmd ::= ALTER TABLE ids cpxName CHANGE TAG ids ids */
 {
     yymsp[-5].minor.yy0.n += yymsp[-4].minor.yy0.n;
 
@@ -2764,7 +2799,7 @@ static void yy_reduce(
     setSQLInfo(pInfo, pAlterTable, NULL, TSDB_SQL_ALTER_TABLE);
 }
         break;
-      case 222: /* cmd ::= ALTER TABLE ids cpxName SET TAG ids EQ tagitem */
+      case 224: /* cmd ::= ALTER TABLE ids cpxName SET TAG ids EQ tagitem */
 {
     yymsp[-6].minor.yy0.n += yymsp[-5].minor.yy0.n;
 
@@ -2776,13 +2811,13 @@ static void yy_reduce(
     setSQLInfo(pInfo, pAlterTable, NULL, TSDB_SQL_ALTER_TABLE);
 }
         break;
-      case 223: /* cmd ::= KILL CONNECTION INTEGER */
+      case 225: /* cmd ::= KILL CONNECTION INTEGER */
 {setKillSQL(pInfo, TSDB_SQL_KILL_CONNECTION, &yymsp[0].minor.yy0);}
         break;
-      case 224: /* cmd ::= KILL STREAM INTEGER COLON INTEGER */
+      case 226: /* cmd ::= KILL STREAM INTEGER COLON INTEGER */
 {yymsp[-2].minor.yy0.n += (yymsp[-1].minor.yy0.n + yymsp[0].minor.yy0.n); setKillSQL(pInfo, TSDB_SQL_KILL_STREAM, &yymsp[-2].minor.yy0);}
         break;
-      case 225: /* cmd ::= KILL QUERY INTEGER COLON INTEGER */
+      case 227: /* cmd ::= KILL QUERY INTEGER COLON INTEGER */
 {yymsp[-2].minor.yy0.n += (yymsp[-1].minor.yy0.n + yymsp[0].minor.yy0.n); setKillSQL(pInfo, TSDB_SQL_KILL_QUERY, &yymsp[-2].minor.yy0);}
         break;
       default:
diff --git a/src/query/tests/resultBufferTest.cpp b/src/query/tests/resultBufferTest.cpp
index e9611a3232..7b946d8589 100644
--- a/src/query/tests/resultBufferTest.cpp
+++ b/src/query/tests/resultBufferTest.cpp
@@ -130,7 +130,6 @@ void recyclePageTest() {
   ASSERT_TRUE(t4 == pBufPage4);
   ASSERT_TRUE(pageId == 4);
   releaseResBufPage(pResultBuf, t4);
-  releaseResBufPage(pResultBuf, t4);
 
   tFilePage* pBufPage5 = getNewDataBuf(pResultBuf, groupId, &pageId);
   tFilePage* t5 = getResBufPage(pResultBuf, pageId);
diff --git a/src/query/tests/tsBufTest.cpp b/src/query/tests/tsBufTest.cpp
index 28b1d9cefe..f8738eec9c 100644
--- a/src/query/tests/tsBufTest.cpp
+++ b/src/query/tests/tsBufTest.cpp
@@ -47,6 +47,8 @@ void simpleTest() {
   EXPECT_EQ(pTSBuf->block.numOfElem, num);
 
   tsBufDestroy(pTSBuf);
+
+  free(list);
 }
 
 // one large list of ts, the ts list need to be split into several small blocks
@@ -71,6 +73,7 @@ void largeTSTest() {
   EXPECT_EQ(pTSBuf->block.numOfElem, num);
 
   tsBufDestroy(pTSBuf);
+  free(list);
 }
 
 void multiTagsTest() {
@@ -208,6 +211,8 @@ void loadDataTest() {
 
   int64_t e = taosGetTimestampUs();
   printf("end:%" PRIu64 ", elapsed:%" PRIu64 ", total obj:%d\n", e, e - s, x);
+  tsBufDestroy(pTSBuf);
+  tsBufDestroy(pNewBuf);
 }
 
 void randomIncTsTest() {}
@@ -338,6 +343,8 @@ void TSTraverse() {
       }
     }
   }
+
+  tsBufDestroy(pTSBuf);
 }
 
 void performanceTest() {}
@@ -352,9 +359,12 @@ void invalidFileTest() {
 
   STSBuf* pNewBuf = tsBufCreateFromFile("/tmp/test", true);
   EXPECT_TRUE(pNewBuf == NULL);
+  tsBufDestroy(pNewBuf);
 
   pNewBuf = tsBufCreateFromFile("/tmp/911", true);
   EXPECT_TRUE(pNewBuf == NULL);
+
+  tsBufDestroy(pNewBuf);
 }
 
 void mergeDiffVnodeBufferTest() {
diff --git a/src/rpc/src/rpcMain.c b/src/rpc/src/rpcMain.c
index 70e5713ee6..13f44f20b7 100644
--- a/src/rpc/src/rpcMain.c
+++ b/src/rpc/src/rpcMain.c
@@ -260,7 +260,7 @@ void *rpcOpen(const SRpcInit *pInit) {
   }
 
   if (pRpc->connType == TAOS_CONN_SERVER) {
-    pRpc->hash = taosHashInit(pRpc->sessions, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BINARY), true);
+    pRpc->hash = taosHashInit(pRpc->sessions, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BINARY), true, true);
     if (pRpc->hash == NULL) {
       tError("%s failed to init string hash", pRpc->label);
       rpcClose(pRpc);
diff --git a/src/sync/src/syncMain.c b/src/sync/src/syncMain.c
index 7c4b57350a..f2abded3b6 100644
--- a/src/sync/src/syncMain.c
+++ b/src/sync/src/syncMain.c
@@ -96,7 +96,7 @@ static void syncModuleInitFunc() {
     return;
   }
     
-  vgIdHash = taosHashInit(TSDB_MIN_VNODES, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), true); 
+  vgIdHash = taosHashInit(TSDB_MIN_VNODES, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), true, true);
   if (vgIdHash == NULL) {
     taosTmrCleanUp(syncTmrCtrl);
     taosCloseTcpThreadPool(tsTcpPool);
diff --git a/src/tsdb/src/tsdbMeta.c b/src/tsdb/src/tsdbMeta.c
index eb1f1fc340..a84bb69777 100644
--- a/src/tsdb/src/tsdbMeta.c
+++ b/src/tsdb/src/tsdbMeta.c
@@ -443,7 +443,7 @@ STsdbMeta *tsdbNewMeta(STsdbCfg *pCfg) {
     goto _err;
   }
 
-  pMeta->uidMap = taosHashInit((size_t)(TSDB_INIT_NTABLES * 1.1), taosGetDefaultHashFunction(TSDB_DATA_TYPE_BIGINT), false);
+  pMeta->uidMap = taosHashInit((size_t)(TSDB_INIT_NTABLES * 1.1), taosGetDefaultHashFunction(TSDB_DATA_TYPE_BIGINT), true, false);
   if (pMeta->uidMap == NULL) {
     terrno = TSDB_CODE_TDB_OUT_OF_MEMORY;
     goto _err;
diff --git a/src/tsdb/src/tsdbRead.c b/src/tsdb/src/tsdbRead.c
index 010955388b..07b50301d3 100644
--- a/src/tsdb/src/tsdbRead.c
+++ b/src/tsdb/src/tsdbRead.c
@@ -208,6 +208,7 @@ TsdbQueryHandleT* tsdbQueryTables(TSDB_REPO_T* tsdb, STsdbQueryCond* pCond, STab
   if (pQueryHandle->statis == NULL) {
     goto out_of_memory;
   }
+
   pQueryHandle->pColumns = taosArrayInit(numOfCols, sizeof(SColumnInfoData));  // todo: use list instead of array?
   if (pQueryHandle->pColumns == NULL) {
     goto out_of_memory;
@@ -229,8 +230,9 @@ TsdbQueryHandleT* tsdbQueryTables(TSDB_REPO_T* tsdb, STsdbQueryCond* pCond, STab
   if (pQueryHandle->pTableCheckInfo == NULL) {
     goto out_of_memory;
   }
+
   STsdbMeta* pMeta = tsdbGetMeta(tsdb);
-  assert(pMeta != NULL);
+  assert(pMeta != NULL && sizeOfGroup >= 1 && pCond != NULL && pCond->numOfCols > 0);
 
   for (int32_t i = 0; i < sizeOfGroup; ++i) {
     SArray* group = *(SArray**) taosArrayGet(groupList->pGroupList, i);
@@ -239,18 +241,26 @@ TsdbQueryHandleT* tsdbQueryTables(TSDB_REPO_T* tsdb, STsdbQueryCond* pCond, STab
     assert(gsize > 0);
 
     for (int32_t j = 0; j < gsize; ++j) {
-      STable* pTable = (STable*) taosArrayGetP(group, j);
+      STableKeyInfo* pKeyInfo = (STableKeyInfo*) taosArrayGet(group, j);
 
       STableCheckInfo info = {
-          .lastKey = pQueryHandle->window.skey,
-          //.tableId = pTable->tableId,
-          .pTableObj = pTable,
+          .lastKey = pKeyInfo->lastKey,
+          .tableId = ((STable*)(pKeyInfo->pTable))->tableId,
+          .pTableObj = pKeyInfo->pTable,
       };
-      info.tableId = pTable->tableId;
 
       assert(info.pTableObj != NULL && (info.pTableObj->type == TSDB_NORMAL_TABLE ||
       info.pTableObj->type == TSDB_CHILD_TABLE || info.pTableObj->type == TSDB_STREAM_TABLE));
 
+      info.tableId.tid = info.pTableObj->tableId.tid;
+      info.tableId.uid = info.pTableObj->tableId.uid;
+
+      if (ASCENDING_TRAVERSE(pQueryHandle->order)) {
+        assert(info.lastKey >= pQueryHandle->window.skey);
+      } else {
+        assert(info.lastKey <= pQueryHandle->window.skey);
+      }
+
       taosArrayPush(pQueryHandle->pTableCheckInfo, &info);
       tsdbDebug("%p check table uid:%"PRId64", tid:%d from lastKey:%"PRId64" %p", pQueryHandle, info.tableId.uid,
           info.tableId.tid, info.lastKey, qinfo);
@@ -326,17 +336,23 @@ static bool initTableMemIterator(STsdbQueryHandle* pHandle, STableCheckInfo* pCh
 
   assert(pCheckInfo->iter == NULL && pCheckInfo->iiter == NULL);
 
-  // TODO: add uid check
-  if (pHandle->mem && pCheckInfo->tableId.tid < pHandle->mem->maxTables &&
-      pHandle->mem->tData[pCheckInfo->tableId.tid] != NULL) {
-    pCheckInfo->iter = tSkipListCreateIterFromVal(pHandle->mem->tData[pCheckInfo->tableId.tid]->pData,
-                                                  (const char*)&pCheckInfo->lastKey, TSDB_DATA_TYPE_TIMESTAMP, order);
+  STableData* pMem = NULL;
+  STableData* pIMem = NULL;
+
+  if (pHandle->mem && pCheckInfo->tableId.tid < pHandle->mem->maxTables) {
+    pMem = pHandle->mem->tData[pCheckInfo->tableId.tid];
+    if (pMem != NULL && pMem->uid == pCheckInfo->tableId.uid) { // check uid
+      pCheckInfo->iter =
+          tSkipListCreateIterFromVal(pMem->pData, (const char*)&pCheckInfo->lastKey, TSDB_DATA_TYPE_TIMESTAMP, order);
+    }
   }
 
-  if (pHandle->imem && pCheckInfo->tableId.tid < pHandle->imem->maxTables &&
-      pHandle->imem->tData[pCheckInfo->tableId.tid] != NULL) {
-    pCheckInfo->iiter = tSkipListCreateIterFromVal(pHandle->imem->tData[pCheckInfo->tableId.tid]->pData,
-                                                   (const char*)&pCheckInfo->lastKey, TSDB_DATA_TYPE_TIMESTAMP, order);
+  if (pHandle->imem && pCheckInfo->tableId.tid < pHandle->imem->maxTables) {
+    pIMem = pHandle->imem->tData[pCheckInfo->tableId.tid];
+    if (pIMem != NULL && pIMem->uid == pCheckInfo->tableId.uid) { // check uid
+      pCheckInfo->iiter =
+          tSkipListCreateIterFromVal(pIMem->pData, (const char*)&pCheckInfo->lastKey, TSDB_DATA_TYPE_TIMESTAMP, order);
+    }
   }
 
   // both iterators are NULL, no data in buffer right now
@@ -356,8 +372,17 @@ static bool initTableMemIterator(STsdbQueryHandle* pHandle, STableCheckInfo* pCh
 
     SDataRow row = *(SDataRow *)SL_GET_NODE_DATA(node);
     TSKEY key = dataRowKey(row);  // first timestamp in buffer
-    tsdbDebug("%p uid:%" PRId64", tid:%d check data in mem from skey:%" PRId64 ", order:%d, %p", pHandle,
-           pCheckInfo->tableId.uid, pCheckInfo->tableId.tid, key, order, pHandle->qinfo);
+    tsdbDebug("%p uid:%" PRId64 ", tid:%d check data in mem from skey:%" PRId64 ", order:%d, ts range in buf:%" PRId64
+              "-%" PRId64 ", lastKey:%" PRId64 ", %p",
+              pHandle, pCheckInfo->tableId.uid, pCheckInfo->tableId.tid, key, order, pMem->keyFirst, pMem->keyLast,
+              pCheckInfo->lastKey, pHandle->qinfo);
+
+    if (ASCENDING_TRAVERSE(order)) {
+      assert(pCheckInfo->lastKey <= key);
+    } else {
+      assert(pCheckInfo->lastKey >= key);
+    }
+
   } else {
     tsdbDebug("%p uid:%"PRId64", tid:%d no data in mem, %p", pHandle, pCheckInfo->tableId.uid, pCheckInfo->tableId.tid,
         pHandle->qinfo);
@@ -369,8 +394,16 @@ static bool initTableMemIterator(STsdbQueryHandle* pHandle, STableCheckInfo* pCh
 
     SDataRow row = *(SDataRow *)SL_GET_NODE_DATA(node);
     TSKEY key = dataRowKey(row);  // first timestamp in buffer
-    tsdbDebug("%p uid:%" PRId64", tid:%d check data in imem from skey:%" PRId64 ", order:%d, %p", pHandle,
-           pCheckInfo->tableId.uid, pCheckInfo->tableId.tid, key, order, pHandle->qinfo);
+    tsdbDebug("%p uid:%" PRId64 ", tid:%d check data in mem from skey:%" PRId64 ", order:%d, ts range in buf:%" PRId64
+              "-%" PRId64 ", lastKey:%" PRId64 ", %p",
+              pHandle, pCheckInfo->tableId.uid, pCheckInfo->tableId.tid, key, order, pIMem->keyFirst, pIMem->keyLast,
+              pCheckInfo->lastKey, pHandle->qinfo);
+
+    if (ASCENDING_TRAVERSE(order)) {
+      assert(pCheckInfo->lastKey <= key);
+    } else {
+      assert(pCheckInfo->lastKey >= key);
+    }
   } else {
     tsdbDebug("%p uid:%"PRId64", tid:%d no data in imem, %p", pHandle, pCheckInfo->tableId.uid, pCheckInfo->tableId.tid,
         pHandle->qinfo);
@@ -2051,7 +2084,9 @@ static int32_t getAllTableList(STable* pSuperTable, SArray* list) {
     SSkipListNode* pNode = tSkipListIterGet(iter);
 
     STable** pTable = (STable**) SL_GET_NODE_DATA((SSkipListNode*) pNode);
-    taosArrayPush(list, pTable);
+
+    STableKeyInfo info = {.pTable = *pTable, .lastKey = TSKEY_INITIAL_VAL};
+    taosArrayPush(list, &info);
   }
 
   tSkipListDestroyIter(iter);
@@ -2089,7 +2124,7 @@ void filterPrepare(void* expr, void* param) {
   pInfo->sch      = *pSchema;
   pInfo->optr     = pExpr->_node.optr;
   pInfo->compare  = getComparFunc(pSchema->type, pInfo->optr);
-  pInfo->param    = pTSSchema;
+  pInfo->indexed  = pTSSchema->columns->colId == pInfo->sch.colId;
 
   if (pInfo->optr == TSDB_RELATION_IN) {
     pInfo->q = (char*) pCond->arr;
@@ -2107,8 +2142,8 @@ typedef struct STableGroupSupporter {
 
 int32_t tableGroupComparFn(const void *p1, const void *p2, const void *param) {
   STableGroupSupporter* pTableGroupSupp = (STableGroupSupporter*) param;
-  STable* pTable1 = *(STable**) p1;
-  STable* pTable2 = *(STable**) p2;
+  STable* pTable1 = ((STableKeyInfo*) p1)->pTable;
+  STable* pTable2 = ((STableKeyInfo*) p2)->pTable;
 
   for (int32_t i = 0; i < pTableGroupSupp->numOfCols; ++i) {
     SColIndex* pColIndex = &pTableGroupSupp->pCols[i];
@@ -2158,12 +2193,14 @@ int32_t tableGroupComparFn(const void *p1, const void *p2, const void *param) {
   return 0;
 }
 
-void createTableGroupImpl(SArray* pGroups, SArray* pTableList, size_t numOfTables, STableGroupSupporter* pSupp,
+void createTableGroupImpl(SArray* pGroups, SArray* pTableList, size_t numOfTables, TSKEY skey, STableGroupSupporter* pSupp,
     __ext_compar_fn_t compareFn) {
   STable* pTable = taosArrayGetP(pTableList, 0);
 
-  SArray* g = taosArrayInit(16, POINTER_BYTES);
-  taosArrayPush(g, &pTable);
+  SArray* g = taosArrayInit(16, sizeof(STableKeyInfo));
+
+  STableKeyInfo info = {.pTable = pTable, .lastKey = skey};
+  taosArrayPush(g, &info);
   tsdbRefTable(pTable);
 
   for (int32_t i = 1; i < numOfTables; ++i) {
@@ -2177,18 +2214,21 @@ void createTableGroupImpl(SArray* pGroups, SArray* pTableList, size_t numOfTable
     assert((*p)->type == TSDB_CHILD_TABLE);
 
     if (ret == 0) {
-      taosArrayPush(g, p);
+      STableKeyInfo info1 = {.pTable = *p, .lastKey = skey};
+      taosArrayPush(g, &info1);
     } else {
       taosArrayPush(pGroups, &g);  // current group is ended, start a new group
-      g = taosArrayInit(16, POINTER_BYTES);
-      taosArrayPush(g, p);
+      g = taosArrayInit(16, sizeof(STableKeyInfo));
+
+      STableKeyInfo info1 = {.pTable = *p, .lastKey = skey};
+      taosArrayPush(g, &info1);
     }
   }
 
   taosArrayPush(pGroups, &g);
 }
 
-SArray* createTableGroup(SArray* pTableList, STSchema* pTagSchema, SColIndex* pCols, int32_t numOfOrderCols) {
+SArray* createTableGroup(SArray* pTableList, STSchema* pTagSchema, SColIndex* pCols, int32_t numOfOrderCols, TSKEY skey) {
   assert(pTableList != NULL);
   SArray* pTableGroup = taosArrayInit(1, POINTER_BYTES);
 
@@ -2199,13 +2239,16 @@ SArray* createTableGroup(SArray* pTableList, STSchema* pTagSchema, SColIndex* pC
   }
 
   if (numOfOrderCols == 0 || size == 1) { // no group by tags clause or only one table
-    SArray* sa = taosArrayInit(size, POINTER_BYTES);
-    for(int32_t i = 0; i < size; ++i) {
-      STable** pTable = taosArrayGet(pTableList, i);
-      assert((*pTable)->type == TSDB_CHILD_TABLE);
+    SArray* sa = taosArrayInit(size, sizeof(STableKeyInfo));
 
-      tsdbRefTable(*pTable);
-      taosArrayPush(sa, pTable);
+    for(int32_t i = 0; i < size; ++i) {
+      STableKeyInfo *pKeyInfo = taosArrayGet(pTableList, i);
+      assert(((STable*)pKeyInfo->pTable)->type == TSDB_CHILD_TABLE);
+
+      tsdbRefTable(pKeyInfo->pTable);
+
+      STableKeyInfo info = {.pTable = pKeyInfo->pTable, .lastKey = skey};
+      taosArrayPush(sa, &info);
     }
 
     taosArrayPush(pTableGroup, &sa);
@@ -2216,8 +2259,8 @@ SArray* createTableGroup(SArray* pTableList, STSchema* pTagSchema, SColIndex* pC
     pSupp->pTagSchema = pTagSchema;
     pSupp->pCols = pCols;
 
-    taosqsort(pTableList->pData, size, POINTER_BYTES, pSupp, tableGroupComparFn);
-    createTableGroupImpl(pTableGroup, pTableList, size, pSupp, tableGroupComparFn);
+    taosqsort(pTableList->pData, size, sizeof(STableKeyInfo), pSupp, tableGroupComparFn);
+    createTableGroupImpl(pTableGroup, pTableList, size, skey, pSupp, tableGroupComparFn);
     taosTFree(pSupp);
   }
 
@@ -2290,7 +2333,7 @@ static int32_t doQueryTableList(STable* pSTable, SArray* pRes, tExprNode* pExpr)
   return TSDB_CODE_SUCCESS;
 }
 
-int32_t tsdbQuerySTableByTagCond(TSDB_REPO_T* tsdb, uint64_t uid, const char* pTagCond, size_t len,
+int32_t tsdbQuerySTableByTagCond(TSDB_REPO_T* tsdb, uint64_t uid, TSKEY skey, const char* pTagCond, size_t len,
                                  int16_t tagNameRelType, const char* tbnameCond, STableGroupInfo* pGroupInfo,
                                  SColIndex* pColIndex, int32_t numOfCols) {
   if (tsdbRLockRepoMeta(tsdb) < 0) goto _error;
@@ -2314,7 +2357,7 @@ int32_t tsdbQuerySTableByTagCond(TSDB_REPO_T* tsdb, uint64_t uid, const char* pT
   }
 
   //NOTE: not add ref count for super table
-  SArray* res = taosArrayInit(8, POINTER_BYTES);
+  SArray* res = taosArrayInit(8, sizeof(STableKeyInfo));
   STSchema* pTagSchema = tsdbGetTableTagSchema(pTable);
 
   // no tags and tbname condition, all child tables of this stable are involved
@@ -2326,7 +2369,7 @@ int32_t tsdbQuerySTableByTagCond(TSDB_REPO_T* tsdb, uint64_t uid, const char* pT
     }
 
     pGroupInfo->numOfTables = taosArrayGetSize(res);
-    pGroupInfo->pGroupList  = createTableGroup(res, pTagSchema, pColIndex, numOfCols);
+    pGroupInfo->pGroupList  = createTableGroup(res, pTagSchema, pColIndex, numOfCols, skey);
 
     tsdbDebug("%p no table name/tag condition, all tables belong to one group, numOfTables:%zu", tsdb, pGroupInfo->numOfTables);
     taosArrayDestroy(res);
@@ -2369,7 +2412,7 @@ int32_t tsdbQuerySTableByTagCond(TSDB_REPO_T* tsdb, uint64_t uid, const char* pT
 
   doQueryTableList(pTable, res, expr);
   pGroupInfo->numOfTables = taosArrayGetSize(res);
-  pGroupInfo->pGroupList  = createTableGroup(res, pTagSchema, pColIndex, numOfCols);
+  pGroupInfo->pGroupList  = createTableGroup(res, pTagSchema, pColIndex, numOfCols, skey);
 
   tsdbDebug("%p stable tid:%d, uid:%"PRIu64" query, numOfTables:%zu, belong to %zu groups", tsdb, pTable->tableId.tid,
       pTable->tableId.uid, pGroupInfo->numOfTables, taosArrayGetSize(pGroupInfo->pGroupList));
@@ -2383,7 +2426,7 @@ int32_t tsdbQuerySTableByTagCond(TSDB_REPO_T* tsdb, uint64_t uid, const char* pT
   return terrno;
 }
 
-int32_t tsdbGetOneTableGroup(TSDB_REPO_T* tsdb, uint64_t uid, STableGroupInfo* pGroupInfo) {
+int32_t tsdbGetOneTableGroup(TSDB_REPO_T* tsdb, uint64_t uid, TSKEY startKey, STableGroupInfo* pGroupInfo) {
   if (tsdbRLockRepoMeta(tsdb) < 0) goto _error;
 
   STable* pTable = tsdbGetTableByUid(tsdbGetMeta(tsdb), uid);
@@ -2400,9 +2443,11 @@ int32_t tsdbGetOneTableGroup(TSDB_REPO_T* tsdb, uint64_t uid, STableGroupInfo* p
   pGroupInfo->numOfTables = 1;
   pGroupInfo->pGroupList = taosArrayInit(1, POINTER_BYTES);
 
-  SArray* group = taosArrayInit(1, POINTER_BYTES);
+  SArray* group = taosArrayInit(1, sizeof(STableKeyInfo));
+
+  STableKeyInfo info = {.pTable = pTable, .lastKey = startKey};
+  taosArrayPush(group, &info);
 
-  taosArrayPush(group, &pTable);
   taosArrayPush(pGroupInfo->pGroupList, &group);
 
   return TSDB_CODE_SUCCESS;
@@ -2419,7 +2464,7 @@ int32_t tsdbGetTableGroupFromIdList(TSDB_REPO_T* tsdb, SArray* pTableIdList, STa
   assert(pTableIdList != NULL);
   size_t size = taosArrayGetSize(pTableIdList);
   pGroupInfo->pGroupList = taosArrayInit(1, POINTER_BYTES);
-  SArray* group = taosArrayInit(1, POINTER_BYTES);
+  SArray* group = taosArrayInit(1, sizeof(STableKeyInfo));
 
   int32_t i = 0;
   for(; i < size; ++i) {
@@ -2437,7 +2482,9 @@ int32_t tsdbGetTableGroupFromIdList(TSDB_REPO_T* tsdb, SArray* pTableIdList, STa
     }
 
     tsdbRefTable(pTable);
-    taosArrayPush(group, &pTable);
+
+    STableKeyInfo info = {.pTable = pTable, .lastKey = id->key};
+    taosArrayPush(group, &info);
   }
 
   if (tsdbUnlockRepoMeta(tsdb) < 0) {
diff --git a/src/util/inc/hash.h b/src/util/inc/hash.h
index 137777f3cb..f289a4e8c3 100644
--- a/src/util/inc/hash.h
+++ b/src/util/inc/hash.h
@@ -20,7 +20,9 @@
 extern "C" {
 #endif
 
+#include "tarray.h"
 #include "hashfunc.h"
+#include "tlockfree.h"
 
 #define HASH_MAX_CAPACITY (1024 * 1024 * 16)
 #define HASH_DEFAULT_LOAD_FACTOR (0.75)
@@ -29,38 +31,45 @@ extern "C" {
 typedef void (*_hash_free_fn_t)(void *param);
 
 typedef struct SHashNode {
-  char *key;
-//  union {
-    struct SHashNode * prev;
-//    struct SHashEntry *prev1;
-//  };
-//
+  char             *key;
+//  struct SHashNode *prev;
   struct SHashNode *next;
   uint32_t          hashVal;  // the hash value of key, if hashVal == HASH_VALUE_IN_TRASH, this node is moved to trash
   uint32_t          keyLen;   // length of the key
-  char              data[];
+  char             *data;
 } SHashNode;
 
-typedef struct SHashObj {
-  SHashNode     **hashList;
-  size_t          capacity;  // number of slots
-  size_t          size;      // number of elements in hash table
-  _hash_fn_t      hashFp;    // hash function
-  _hash_free_fn_t freeFp;    // hash node free callback function
+typedef enum SHashLockTypeE {
+  HASH_NO_LOCK     = 0,
+  HASH_ENTRY_LOCK  = 1,
+} SHashLockTypeE;
 
-#if defined(LINUX)
-  pthread_rwlock_t *lock;
-#else
-  pthread_mutex_t *lock;
-#endif
+typedef struct SHashEntry {
+  int32_t    num;      // number of elements in current entry
+  SRWLatch   latch;    // entry latch
+  SHashNode *next;
+} SHashEntry;
+
+typedef struct SHashObj {
+  SHashEntry    **hashList;
+  size_t          capacity;     // number of slots
+  size_t          size;         // number of elements in hash table
+  _hash_fn_t      hashFp;       // hash function
+  _hash_free_fn_t freeFp;       // hash node free callback function
+
+  SRWLatch        lock;         // read-write spin lock
+  SHashLockTypeE  type;         // lock type
+  bool            enableUpdate; // enable update
+  SArray         *pMemBlock;    // memory block allocated for SHashEntry
 } SHashObj;
 
 typedef struct SHashMutableIterator {
-  SHashObj * pHashObj;
+  SHashObj  *pHashObj;
   int32_t    entryIndex;
   SHashNode *pCur;
-  SHashNode *pNext;  // current node can be deleted for mutable iterator, so keep the next one before return current
-  int32_t    num;    // already check number of elements in hash table
+  SHashNode *pNext;           // current node can be deleted for mutable iterator, so keep the next one before return current
+  size_t     numOfChecked;    // already check number of elements in hash table
+  size_t     numOfEntries;    // number of entries while the iterator is created
 } SHashMutableIterator;
 
 /**
@@ -71,7 +80,7 @@ typedef struct SHashMutableIterator {
  * @param threadsafe  thread safe or not
  * @return
  */
-SHashObj *taosHashInit(size_t capacity, _hash_fn_t fn, bool threadsafe);
+SHashObj *taosHashInit(size_t capacity, _hash_fn_t fn, bool update, SHashLockTypeE type);
 
 /**
  * return the size of hash table
@@ -101,13 +110,19 @@ int32_t taosHashPut(SHashObj *pHashObj, const void *key, size_t keyLen, void *da
  */
 void *taosHashGet(SHashObj *pHashObj, const void *key, size_t keyLen);
 
+void *taosHashGetCB(SHashObj *pHashObj, const void *key, size_t keyLen, void(*fp)(void*));
+
 /**
  * remove item with the specified key
  * @param pHashObj
  * @param key
  * @param keyLen
  */
-void taosHashRemove(SHashObj *pHashObj, const void *key, size_t keyLen);
+int32_t taosHashRemove(SHashObj *pHashObj, const void *key, size_t keyLen);
+
+int32_t taosHashRemoveWithData(SHashObj *pHashObj, const void *key, size_t keyLen, void* data, size_t dsize);
+
+int32_t taosHashCondTraverse(SHashObj *pHashObj, bool (*fp)(void *, void *), void *param);
 
 /**
  * clean up hash table
@@ -115,13 +130,6 @@ void taosHashRemove(SHashObj *pHashObj, const void *key, size_t keyLen);
  */
 void taosHashCleanup(SHashObj *pHashObj);
 
-/**
- * Set the free callback function
- * This function if set will be invoked right before freeing each hash node
- * @param pHashObj
- */
-void taosHashSetFreecb(SHashObj *pHashObj, _hash_free_fn_t freeFp);
-
 /**
  *
  * @param pHashObj
diff --git a/src/util/inc/tcache.h b/src/util/inc/tcache.h
index 1e2aeae394..11121fcf3b 100644
--- a/src/util/inc/tcache.h
+++ b/src/util/inc/tcache.h
@@ -121,7 +121,7 @@ void *taosCacheAcquireByKey(SCacheObj *pCacheObj, const void *key, size_t keyLen
  * @param expireTime    new expire time of data
  * @return
  */ 
-void* taosCacheUpdateExpireTimeByName(SCacheObj *pCacheObj, void *key, size_t keyLen, uint64_t expireTime);
+//void* taosCacheUpdateExpireTimeByName(SCacheObj *pCacheObj, void *key, size_t keyLen, uint64_t expireTime);
 
 /**
  * Add one reference count for the exist data, and assign this data for a new owner.
diff --git a/src/util/inc/tstoken.h b/src/util/inc/tstoken.h
index 705c52af47..c1c6f2de7a 100644
--- a/src/util/inc/tstoken.h
+++ b/src/util/inc/tstoken.h
@@ -24,8 +24,6 @@ extern "C" {
 #include "tutil.h"
 #include "ttokendef.h"
 
-
-
 #define TSQL_TBNAME   "TBNAME"
 #define TSQL_TBNAME_L "tbname"
 
diff --git a/src/util/src/hash.c b/src/util/src/hash.c
index 37c9146a49..8df3e3d4d3 100644
--- a/src/util/src/hash.c
+++ b/src/util/src/hash.c
@@ -18,64 +18,52 @@
 #include "tulog.h"
 #include "taosdef.h"
 
-static FORCE_INLINE void __wr_lock(void *lock) {
-  if (lock == NULL) {
+#define HASH_NEED_RESIZE(_h) ((_h)->size >= (_h)->capacity * HASH_DEFAULT_LOAD_FACTOR)
+
+#define DO_FREE_HASH_NODE(_n) \
+  do {                        \
+    taosTFree((_n)->data);    \
+    taosTFree(_n);            \
+  } while (0)
+
+#define FREE_HASH_NODE(_h, _n)  \
+  do {                          \
+    if ((_h)->freeFp) {         \
+      (_h)->freeFp((_n)->data); \
+    }                           \
+                                \
+    DO_FREE_HASH_NODE(_n);      \
+  } while (0);
+
+static FORCE_INLINE void __wr_lock(void *lock, int32_t type) {
+  if (type == HASH_NO_LOCK) {
+    return;
+  }
+  taosWLockLatch(lock);
+}
+
+static FORCE_INLINE void __rd_lock(void *lock, int32_t type) {
+  if (type == HASH_NO_LOCK) {
     return;
   }
 
-#if defined(LINUX)
-  pthread_rwlock_wrlock(lock);
-#else
-  pthread_mutex_lock(lock);
-#endif
+  taosRLockLatch(lock);
 }
 
-static FORCE_INLINE void __rd_lock(void *lock) {
-  if (lock == NULL) {
+static FORCE_INLINE void __rd_unlock(void *lock, int32_t type) {
+  if (type == HASH_NO_LOCK) {
     return;
   }
 
-#if defined(LINUX)
-  pthread_rwlock_rdlock(lock);
-#else
-  pthread_mutex_lock(lock);
-#endif
+  taosRUnLockLatch(lock);
 }
 
-static FORCE_INLINE void __unlock(void *lock) {
-  if (lock == NULL) {
+static FORCE_INLINE void __wr_unlock(void *lock, int32_t type) {
+  if (type == HASH_NO_LOCK) {
     return;
   }
 
-#if defined(LINUX)
-  pthread_rwlock_unlock(lock);
-#else
-  pthread_mutex_unlock(lock);
-#endif
-}
-
-static FORCE_INLINE int32_t __lock_init(void *lock) {
-  if (lock == NULL) {
-    return 0;
-  }
-
-#if defined(LINUX)
-  return pthread_rwlock_init(lock, NULL);
-#else
-  return pthread_mutex_init(lock, NULL);
-#endif
-}
-
-static FORCE_INLINE void __lock_destroy(void *lock) {
-  if (lock == NULL) {
-    return;
-  }
-
-#if defined(LINUX)
-  pthread_rwlock_destroy(lock);
-#else
-  pthread_mutex_destroy(lock);
-#endif
+  taosWUnLockLatch(lock);
 }
 
 static FORCE_INLINE int32_t taosHashCapacity(int32_t length) {
@@ -86,37 +74,17 @@ static FORCE_INLINE int32_t taosHashCapacity(int32_t length) {
   return i;
 }
 
-/**
- * Get SHashNode from hashlist, nodes from trash are not included.
- * @param pHashObj  Cache objection
- * @param key       key for hash
- * @param keyLen    key length
- * @param hashVal   hash value by hash function
- * @return
- */
-FORCE_INLINE SHashNode *doGetNodeFromHashTable(SHashObj *pHashObj, const void *key, uint32_t keyLen, uint32_t *hashVal) {
-  uint32_t hash = (*pHashObj->hashFp)(key, keyLen);
-  
-  int32_t    slot = HASH_INDEX(hash, pHashObj->capacity);
-  SHashNode *pNode = pHashObj->hashList[slot];
-  
+static FORCE_INLINE SHashNode *doSearchInEntryList(SHashEntry *pe, const void *key, size_t keyLen, uint32_t hashVal) {
+  SHashNode *pNode = pe->next;
   while (pNode) {
     if ((pNode->keyLen == keyLen) && (memcmp(pNode->key, key, keyLen) == 0)) {
+      assert(pNode->hashVal == hashVal);
       break;
     }
-    
+
     pNode = pNode->next;
   }
-  
-  if (pNode) {
-    assert(HASH_INDEX(pNode->hashVal, pHashObj->capacity) == slot);
-  }
-  
-  // return the calculated hash value, to avoid calculating it again in other functions
-  if (hashVal != NULL) {
-    *hashVal = hash;
-  }
-  
+
   return pNode;
 }
 
@@ -147,7 +115,13 @@ static SHashNode *doCreateHashNode(const void *key, size_t keyLen, const void *p
  * @param dsize   size of actual data
  * @return        hash node
  */
-static SHashNode *doUpdateHashNode(SHashNode *pNode, const void *key, size_t keyLen, const void *pData, size_t dsize);
+static FORCE_INLINE SHashNode *doUpdateHashNode(SHashNode *pNode, SHashNode *pNewNode) {
+  assert(pNode->keyLen == pNewNode->keyLen);
+  SWAP(pNode->key, pNewNode->key, void *);
+  SWAP(pNode->data, pNewNode->data, void *);
+
+  return pNewNode;
+}
 
 /**
  * insert the hash node at the front of the linked list
@@ -155,7 +129,7 @@ static SHashNode *doUpdateHashNode(SHashNode *pNode, const void *key, size_t key
  * @param pHashObj
  * @param pNode
  */
-static void doAddToHashTable(SHashObj *pHashObj, SHashNode *pNode);
+static void pushfrontNodeInEntryList(SHashEntry *pEntry, SHashNode *pNode);
 
 /**
  * Get the next element in hash table for iterator
@@ -164,7 +138,7 @@ static void doAddToHashTable(SHashObj *pHashObj, SHashNode *pNode);
  */
 static SHashNode *getNextHashNode(SHashMutableIterator *pIter);
 
-SHashObj *taosHashInit(size_t capacity, _hash_fn_t fn, bool threadsafe) {
+SHashObj *taosHashInit(size_t capacity, _hash_fn_t fn, bool update, SHashLockTypeE type) {
   if (capacity == 0 || fn == NULL) {
     return NULL;
   }
@@ -180,151 +154,360 @@ SHashObj *taosHashInit(size_t capacity, _hash_fn_t fn, bool threadsafe) {
   assert((pHashObj->capacity & (pHashObj->capacity - 1)) == 0);
 
   pHashObj->hashFp = fn;
+  pHashObj->type = type;
+  pHashObj->enableUpdate = update;
 
-  pHashObj->hashList = (SHashNode **)calloc(pHashObj->capacity, POINTER_BYTES);
+  pHashObj->hashList = (SHashEntry **)calloc(pHashObj->capacity, sizeof(void *));
   if (pHashObj->hashList == NULL) {
     free(pHashObj);
     uError("failed to allocate memory, reason:%s", strerror(errno));
     return NULL;
-  }
+  } else {
+    pHashObj->pMemBlock = taosArrayInit(8, sizeof(void *));
 
-  if (threadsafe) {
-#if defined(LINUX)
-    pHashObj->lock = calloc(1, sizeof(pthread_rwlock_t));
-#else
-    pHashObj->lock = calloc(1, sizeof(pthread_mutex_t));
-#endif
-  }
+    void *p = calloc(pHashObj->capacity, sizeof(SHashEntry));
+    for (int32_t i = 0; i < pHashObj->capacity; ++i) {
+      pHashObj->hashList[i] = p + i * sizeof(SHashEntry);
+    }
 
-  if (__lock_init(pHashObj->lock) != 0) {
-    free(pHashObj->hashList);
-    free(pHashObj);
-
-    uError("failed to init lock, reason:%s", strerror(errno));
-    return NULL;
+    taosArrayPush(pHashObj->pMemBlock, &p);
   }
 
   return pHashObj;
 }
 
-size_t taosHashGetSize(const SHashObj *pHashObj) {
-  if (pHashObj == NULL) {
-    return 0;
-  }
-
-  return pHashObj->size;
-}
+size_t taosHashGetSize(const SHashObj *pHashObj) { return (pHashObj == NULL) ? 0 : pHashObj->size; }
 
 int32_t taosHashPut(SHashObj *pHashObj, const void *key, size_t keyLen, void *data, size_t size) {
-  __wr_lock(pHashObj->lock);
-
-  uint32_t   hashVal = 0;
-  SHashNode *pNode = doGetNodeFromHashTable(pHashObj, key, (uint32_t)keyLen, &hashVal);
-
-  if (pNode == NULL) {  // no data in hash table with the specified key, add it into hash table
-    taosHashTableResize(pHashObj);
-
-    SHashNode *pNewNode = doCreateHashNode(key, keyLen, data, size, hashVal);
-    if (pNewNode == NULL) {
-      __unlock(pHashObj->lock);
-
-      return -1;
-    }
-
-    doAddToHashTable(pHashObj, pNewNode);
-  } else {
-    SHashNode *pNewNode = doUpdateHashNode(pNode, key, keyLen, data, size);
-    if (pNewNode == NULL) {
-      __unlock(pHashObj->lock);
-      return -1;
-    }
-
-    if (pNewNode->prev) {
-      pNewNode->prev->next = pNewNode;
-    } else {
-      int32_t slot = HASH_INDEX(pNewNode->hashVal, pHashObj->capacity);
-      
-      assert(pHashObj->hashList[slot] == pNode);
-      pHashObj->hashList[slot] = pNewNode;
-    }
-  
-    if (pNewNode->next) {
-      (pNewNode->next)->prev = pNewNode;
-    }
+  uint32_t   hashVal = (*pHashObj->hashFp)(key, keyLen);
+  SHashNode *pNewNode = doCreateHashNode(key, keyLen, data, size, hashVal);
+  if (pNewNode == NULL) {
+    return -1;
   }
 
-  __unlock(pHashObj->lock);
-  return 0;
+  // need the resize process, write lock applied
+  if (HASH_NEED_RESIZE(pHashObj)) {
+    __wr_lock(&pHashObj->lock, pHashObj->type);
+    taosHashTableResize(pHashObj);
+    __wr_unlock(&pHashObj->lock, pHashObj->type);
+  }
+
+  __rd_lock(&pHashObj->lock, pHashObj->type);
+
+  int32_t     slot = HASH_INDEX(hashVal, pHashObj->capacity);
+  SHashEntry *pe = pHashObj->hashList[slot];
+
+  if (pHashObj->type == HASH_ENTRY_LOCK) {
+    taosWLockLatch(&pe->latch);
+  }
+
+  SHashNode *pNode = pe->next;
+  if (pe->num > 0) {
+    assert(pNode != NULL);
+  } else {
+    assert(pNode == NULL);
+  }
+
+  while (pNode) {
+    if ((pNode->keyLen == keyLen) && (memcmp(pNode->key, key, keyLen) == 0)) {
+      assert(pNode->hashVal == hashVal);
+      break;
+    }
+
+    pNode = pNode->next;
+  }
+
+  if (pNode == NULL) {
+    // no data in hash table with the specified key, add it into hash table
+    pushfrontNodeInEntryList(pe, pNewNode);
+
+    if (pe->num == 0) {
+      assert(pe->next == NULL);
+    } else {
+      assert(pe->next != NULL);
+    }
+
+    if (pHashObj->type == HASH_ENTRY_LOCK) {
+      taosWUnLockLatch(&pe->latch);
+    }
+
+    // enable resize
+    __rd_unlock(&pHashObj->lock, pHashObj->type);
+    atomic_add_fetch_64(&pHashObj->size, 1);
+
+    return 0;
+  } else {
+    // not support the update operation, return error
+    if (pHashObj->enableUpdate) {
+      doUpdateHashNode(pNode, pNewNode);
+    }
+
+    if (pHashObj->type == HASH_ENTRY_LOCK) {
+      taosWUnLockLatch(&pe->latch);
+    }
+
+    // enable resize
+    __rd_unlock(&pHashObj->lock, pHashObj->type);
+
+    DO_FREE_HASH_NODE(pNewNode);
+    return pHashObj->enableUpdate ? 0 : -1;
+  }
 }
 
 void *taosHashGet(SHashObj *pHashObj, const void *key, size_t keyLen) {
-  __rd_lock(pHashObj->lock);
+  return taosHashGetCB(pHashObj, key, keyLen, NULL);
+}
 
-  uint32_t   hashVal = 0;
-  SHashNode *pNode = doGetNodeFromHashTable(pHashObj, key, (int32_t)keyLen, &hashVal);
-
-  __unlock(pHashObj->lock);
-
-  if (pNode != NULL) {
-    assert(pNode->hashVal == hashVal);
-
-    return pNode->data;
-  } else {
+void *taosHashGetCB(SHashObj *pHashObj, const void *key, size_t keyLen, void (*fp)(void *)) {
+  if (pHashObj->size <= 0 || keyLen == 0 || key == NULL) {
     return NULL;
   }
+
+  uint32_t hashVal = (*pHashObj->hashFp)(key, keyLen);
+
+  // only add the read lock to disable the resize process
+  __rd_lock(&pHashObj->lock, pHashObj->type);
+
+  int32_t     slot = HASH_INDEX(hashVal, pHashObj->capacity);
+  SHashEntry *pe = pHashObj->hashList[slot];
+
+  // no data, return directly
+  if (atomic_load_32(&pe->num) == 0) {
+
+    __rd_unlock(&pHashObj->lock, pHashObj->type);
+    return NULL;
+  }
+
+  char *data = NULL;
+
+  // lock entry
+  if (pHashObj->type == HASH_ENTRY_LOCK) {
+    taosRLockLatch(&pe->latch);
+  }
+
+  if (pe->num > 0) {
+    assert(pe->next != NULL);
+  } else {
+    assert(pe->next == NULL);
+  }
+
+  SHashNode *pNode = doSearchInEntryList(pe, key, keyLen, hashVal);
+  if (pNode != NULL) {
+    if (fp != NULL) {
+      fp(pNode->data);
+    }
+
+    data = pNode->data;
+  }
+
+  if (pHashObj->type == HASH_ENTRY_LOCK) {
+    taosRUnLockLatch(&pe->latch);
+  }
+
+  __rd_unlock(&pHashObj->lock, pHashObj->type);
+  return data;
+}
+
+int32_t taosHashRemove(SHashObj *pHashObj, const void *key, size_t keyLen) {
+  return taosHashRemoveWithData(pHashObj, key, keyLen, NULL, 0);
+}
+
+int32_t taosHashRemoveWithData(SHashObj *pHashObj, const void *key, size_t keyLen, void *data, size_t dsize) {
+  if (pHashObj == NULL || pHashObj->size <= 0) {
+    return -1;
+  }
+
+  uint32_t hashVal = (*pHashObj->hashFp)(key, keyLen);
+
+  // disable the resize process
+  __rd_lock(&pHashObj->lock, pHashObj->type);
+
+  int32_t     slot = HASH_INDEX(hashVal, pHashObj->capacity);
+  SHashEntry *pe = pHashObj->hashList[slot];
+
+  // no data, return directly
+  if (pe->num == 0) {
+    assert(pe->next == NULL);
+    __rd_unlock(&pHashObj->lock, pHashObj->type);
+    return -1;
+  }
+
+  if (pHashObj->type == HASH_ENTRY_LOCK) {
+    taosWLockLatch(&pe->latch);
+  }
+
+  if (pe->num == 0) {
+    assert(pe->next == NULL);
+  } else {
+    assert(pe->next != NULL);
+  }
+
+  // double check after locked
+  if (pe->num == 0) {
+    assert(pe->next == NULL);
+    taosWUnLockLatch(&pe->latch);
+
+    __rd_unlock(&pHashObj->lock, pHashObj->type);
+    return -1;
+  }
+
+  SHashNode *pNode = pe->next;
+  SHashNode *pRes = NULL;
+
+  // remove it
+  if ((pNode->keyLen == keyLen) && (memcmp(pNode->key, key, keyLen) == 0)) {
+    pe->num -= 1;
+    pRes = pNode;
+    pe->next = pNode->next;
+  } else {
+    while (pNode->next != NULL) {
+      if (((pNode->next)->keyLen == keyLen) && (memcmp((pNode->next)->key, key, keyLen) == 0)) {
+        assert((pNode->next)->hashVal == hashVal);
+        break;
+      }
+
+      pNode = pNode->next;
+    }
+
+
+    if (pNode->next != NULL) {
+      pe->num -= 1;
+      pRes = pNode->next;
+      pNode->next = pNode->next->next;
+    }
+  }
+
+  if (pHashObj->type == HASH_ENTRY_LOCK) {
+    taosWUnLockLatch(&pe->latch);
+  }
+
+  __rd_unlock(&pHashObj->lock, pHashObj->type);
+
+  if (data != NULL && pRes != NULL) {
+    memcpy(data, pRes->data, dsize);
+  }
+
+  if (pRes != NULL) {
+    atomic_sub_fetch_64(&pHashObj->size, 1);
+    FREE_HASH_NODE(pHashObj, pRes);
+
+    if (pe->num == 0) {
+      assert(pe->next == NULL);
+    } else {
+      assert(pe->next != NULL);
+    }
+
+    return 0;
+  } else {
+
+    if (pe->num == 0) {
+      assert(pe->next == NULL);
+    } else {
+      assert(pe->next != NULL);
+    }
+
+    return -1;
+  }
 }
 
-void taosHashRemove(SHashObj *pHashObj, const void *key, size_t keyLen) {
-  __wr_lock(pHashObj->lock);
-
-  uint32_t   val = 0;
-  SHashNode *pNode = doGetNodeFromHashTable(pHashObj, key, (uint32_t)keyLen, &val);
-  if (pNode == NULL) {
-    __unlock(pHashObj->lock);
-    return;
+int32_t taosHashCondTraverse(SHashObj *pHashObj, bool (*fp)(void *, void *), void *param) {
+  if (pHashObj == NULL || pHashObj->size == 0) {
+    return 0;
   }
 
-  SHashNode *pNext = pNode->next;
-  if (pNode->prev == NULL) {
-    int32_t slot = HASH_INDEX(val, pHashObj->capacity);
-    assert(pHashObj->hashList[slot] == pNode);
-    
-    pHashObj->hashList[slot] = pNext;
-  } else {
-    pNode->prev->next = pNext;
-  }
-  
-  if (pNext != NULL) {
-    pNext->prev = pNode->prev;
+  // disable the resize process
+  __rd_lock(&pHashObj->lock, pHashObj->type);
+
+  int32_t numOfEntries = pHashObj->capacity;
+  for (int32_t i = 0; i < numOfEntries; ++i) {
+    SHashEntry *pEntry = pHashObj->hashList[i];
+    if (pEntry->num == 0) {
+      continue;
+    }
+
+    if (pHashObj->type == HASH_ENTRY_LOCK) {
+      taosWLockLatch(&pEntry->latch);
+    }
+
+    // todo remove the first node
+    SHashNode *pNode = NULL;
+    while((pNode = pEntry->next) != NULL) {
+      if (fp && (!fp(param, pNode->data))) {
+        pEntry->num -= 1;
+        atomic_sub_fetch_64(&pHashObj->size, 1);
+
+        pEntry->next = pNode->next;
+
+        if (pEntry->num == 0) {
+          assert(pEntry->next == NULL);
+        } else {
+          assert(pEntry->next != NULL);
+        }
+
+        FREE_HASH_NODE(pHashObj, pNode);
+      } else {
+        break;
+      }
+    }
+
+    // handle the following node
+    if (pNode != NULL) {
+      assert(pNode == pEntry->next);
+      SHashNode *pNext = NULL;
+
+      while ((pNext = pNode->next) != NULL) {
+        // not qualified, remove it
+        if (fp && (!fp(param, pNext->data))) {
+          pNode->next = pNext->next;
+          pEntry->num -= 1;
+          atomic_sub_fetch_64(&pHashObj->size, 1);
+
+          if (pEntry->num == 0) {
+            assert(pEntry->next == NULL);
+          } else {
+            assert(pEntry->next != NULL);
+          }
+
+          FREE_HASH_NODE(pHashObj, pNext);
+        } else {
+          pNode = pNext;
+        }
+      }
+    }
+
+    if (pHashObj->type == HASH_ENTRY_LOCK) {
+      taosWUnLockLatch(&pEntry->latch);
+    }
   }
 
-  pHashObj->size--;
-
-  pNode->next = NULL;
-  pNode->prev = NULL;
-
-  taosTFree(pNode);
-  __unlock(pHashObj->lock);
+  __rd_unlock(&pHashObj->lock, pHashObj->type);
+  return 0;
 }
 
 void taosHashCleanup(SHashObj *pHashObj) {
-  if (pHashObj == NULL) return;
+  if (pHashObj == NULL) {
+    return;
+  }
 
   SHashNode *pNode, *pNext;
 
-  __wr_lock(pHashObj->lock);
+  __wr_lock(&pHashObj->lock, pHashObj->type);
 
   if (pHashObj->hashList) {
     for (int32_t i = 0; i < pHashObj->capacity; ++i) {
-      pNode = pHashObj->hashList[i];
+      SHashEntry *pEntry = pHashObj->hashList[i];
+      if (pEntry->num == 0) {
+        assert(pEntry->next == 0);
+        continue;
+      }
+
+      pNode = pEntry->next;
+      assert(pNode != NULL);
 
       while (pNode) {
         pNext = pNode->next;
-        if (pHashObj->freeFp) {
-          pHashObj->freeFp(pNode->data);
-        }
+        FREE_HASH_NODE(pHashObj, pNode);
 
-        free(pNode);
         pNode = pNext;
       }
     }
@@ -332,20 +515,19 @@ void taosHashCleanup(SHashObj *pHashObj) {
     free(pHashObj->hashList);
   }
 
-  __unlock(pHashObj->lock);
-  __lock_destroy(pHashObj->lock);
+  __wr_unlock(&pHashObj->lock, pHashObj->type);
 
-  taosTFree(pHashObj->lock);
-  memset(pHashObj, 0, sizeof(SHashObj));
-  free(pHashObj);
-}
-
-void taosHashSetFreecb(SHashObj *pHashObj, _hash_free_fn_t freeFp) {
-  if (pHashObj == NULL || freeFp == NULL) {
-    return;
+  // destroy mem block
+  size_t memBlock = taosArrayGetSize(pHashObj->pMemBlock);
+  for (int32_t i = 0; i < memBlock; ++i) {
+    void *p = taosArrayGetP(pHashObj->pMemBlock, i);
+    taosTFree(p);
   }
 
-  pHashObj->freeFp = freeFp;
+  taosArrayDestroy(pHashObj->pMemBlock);
+
+  memset(pHashObj, 0, sizeof(SHashObj));
+  free(pHashObj);
 }
 
 SHashMutableIterator *taosHashCreateIter(SHashObj *pHashObj) {
@@ -355,6 +537,9 @@ SHashMutableIterator *taosHashCreateIter(SHashObj *pHashObj) {
   }
 
   pIter->pHashObj = pHashObj;
+
+  // keep it in local variable, in case the resize operation expand the size
+  pIter->numOfEntries = pHashObj->capacity;
   return pIter;
 }
 
@@ -369,28 +554,42 @@ bool taosHashIterNext(SHashMutableIterator *pIter) {
   }
 
   // check the first one
-  if (pIter->num == 0) {
+  if (pIter->numOfChecked == 0) {
     assert(pIter->pCur == NULL && pIter->pNext == NULL);
 
     while (1) {
-      SHashNode *pEntry = pIter->pHashObj->hashList[pIter->entryIndex];
-      if (pEntry == NULL) {
+      SHashEntry *pEntry = pIter->pHashObj->hashList[pIter->entryIndex];
+      if (pEntry->num == 0) {
+        assert(pEntry->next == NULL);
+
         pIter->entryIndex++;
         continue;
       }
 
-      pIter->pCur = pEntry;
+      if (pIter->pHashObj->type == HASH_ENTRY_LOCK) {
+        taosRLockLatch(&pEntry->latch);
+      }
+
+      pIter->pCur = pEntry->next;
 
       if (pIter->pCur->next) {
         pIter->pNext = pIter->pCur->next;
+
+        if (pIter->pHashObj->type == HASH_ENTRY_LOCK) {
+          taosRUnLockLatch(&pEntry->latch);
+        }
       } else {
+        if (pIter->pHashObj->type == HASH_ENTRY_LOCK) {
+          taosRUnLockLatch(&pEntry->latch);
+        }
+
         pIter->pNext = getNextHashNode(pIter);
       }
 
       break;
     }
 
-    pIter->num++;
+    pIter->numOfChecked++;
     return true;
   } else {
     assert(pIter->pCur != NULL);
@@ -400,7 +599,7 @@ bool taosHashIterNext(SHashMutableIterator *pIter) {
       return false;
     }
 
-    pIter->num++;
+    pIter->numOfChecked++;
 
     if (pIter->pCur->next) {
       pIter->pNext = pIter->pCur->next;
@@ -432,19 +631,9 @@ int32_t taosHashGetMaxOverflowLinkLength(const SHashObj *pHashObj) {
   int32_t num = 0;
 
   for (int32_t i = 0; i < pHashObj->size; ++i) {
-    SHashNode *pEntry = pHashObj->hashList[i];
-    if (pEntry == NULL) {
-      continue;
-    }
-    
-    int32_t j = 0;
-    while(pEntry != NULL) {
-      pEntry = pEntry->next;
-      j++;
-    }
-    
-    if (num < j) {
-      num = j;
+    SHashEntry *pEntry = pHashObj->hashList[i];
+    if (num < pEntry->num) {
+      num = pEntry->num;
     }
   }
 
@@ -452,146 +641,166 @@ int32_t taosHashGetMaxOverflowLinkLength(const SHashObj *pHashObj) {
 }
 
 void taosHashTableResize(SHashObj *pHashObj) {
-  if (pHashObj->size < pHashObj->capacity * HASH_DEFAULT_LOAD_FACTOR) {
+  if (!HASH_NEED_RESIZE(pHashObj)) {
     return;
   }
-  
+
   // double the original capacity
   SHashNode *pNode = NULL;
   SHashNode *pNext = NULL;
-  
-  int32_t newSize = (int32_t)(pHashObj->capacity) << 1u;
+
+  int32_t newSize = pHashObj->capacity << 1u;
   if (newSize > HASH_MAX_CAPACITY) {
-//    uDebug("current capacity:%d, maximum capacity:%d, no resize applied due to limitation is reached",
-//           pHashObj->capacity, HASH_MAX_CAPACITY);
+    //    uDebug("current capacity:%d, maximum capacity:%d, no resize applied due to limitation is reached",
+    //           pHashObj->capacity, HASH_MAX_CAPACITY);
     return;
   }
 
-  int32_t pointerSize = POINTER_BYTES;
-  void *pNewEntry = realloc(pHashObj->hashList, pointerSize * newSize);
-  if (pNewEntry == NULL) {// todo handle error
-//    uDebug("cache resize failed due to out of memory, capacity remain:%d", pHashObj->capacity);
+  int64_t st = taosGetTimestampUs();
+  void *pNewEntryList = realloc(pHashObj->hashList, sizeof(void*) * newSize);
+  if (pNewEntryList == NULL) {  // todo handle error
+    //    uDebug("cache resize failed due to out of memory, capacity remain:%d", pHashObj->capacity);
     return;
   }
-  
-  pHashObj->hashList = pNewEntry;
-  memset(&pHashObj->hashList[pHashObj->capacity], 0, POINTER_BYTES * (newSize - pHashObj->capacity));
-  
+
+  pHashObj->hashList = pNewEntryList;
+
+  size_t inc = newSize - pHashObj->capacity;
+  void * p = calloc(inc, sizeof(SHashEntry));
+
+  for (int32_t i = 0; i < inc; ++i) {
+    pHashObj->hashList[i + pHashObj->capacity] = p + i * sizeof(SHashEntry);
+  }
+
+  taosArrayPush(pHashObj->pMemBlock, &p);
+
   pHashObj->capacity = newSize;
-  
   for (int32_t i = 0; i < pHashObj->capacity; ++i) {
-    pNode = pHashObj->hashList[i];
-    if (pNode != NULL) {
-      assert(pNode->prev == NULL);
+    SHashEntry *pe = pHashObj->hashList[i];
+
+    if (pe->num == 0) {
+      assert(pe->next == NULL);
+    } else {
+      assert(pe->next != NULL);
     }
-    
-    while (pNode) {
+
+    if (pe->num == 0) {
+      assert(pe->next == NULL);
+      continue;
+    }
+
+    while ((pNode = pe->next) != NULL) {
       int32_t j = HASH_INDEX(pNode->hashVal, pHashObj->capacity);
-      if (j == i) {  // this key locates in the same slot, no need to relocate it
-        pNode = pNode->next;
-      } else {
-        pNext = pNode->next;
-        
-        if (pNode->prev == NULL) {  // first node of the overflow linked list
-          pHashObj->hashList[i] = pNext;
+      if (j != i) {
+        pe->num -= 1;
+        pe->next = pNode->next;
+
+        if (pe->num == 0) {
+          assert(pe->next == NULL);
         } else {
-          pNode->prev->next = pNext;
+          assert(pe->next != NULL);
         }
-        
-        if (pNext != NULL) {
-          pNext->prev = pNode->prev;
-        }
-        
-        // clear pointer
-        pNode->next = NULL;
-        pNode->prev = NULL;
-        
-        // added into new slot
-        SHashNode *pNew = pHashObj->hashList[j];
-        if (pNew != NULL) {
-          assert(pNew->prev == NULL);
-          pNew->prev = pNode;
-        }
-        
-        pNode->next = pNew;
-        pHashObj->hashList[j] = pNode;
-        
-        // continue
-        pNode = pNext;
+
+        SHashEntry *pNewEntry = pHashObj->hashList[j];
+        pushfrontNodeInEntryList(pNewEntry, pNode);
+      } else {
+        break;
       }
     }
+
+    if (pNode != NULL) {
+      while ((pNext = pNode->next) != NULL) {
+        int32_t j = HASH_INDEX(pNext->hashVal, pHashObj->capacity);
+        if (j != i) {
+          pe->num -= 1;
+
+          pNode->next = pNext->next;
+          pNext->next = NULL;
+
+          // added into new slot
+          SHashEntry *pNewEntry = pHashObj->hashList[j];
+
+          if (pNewEntry->num == 0) {
+            assert(pNewEntry->next == NULL);
+          } else {
+            assert(pNewEntry->next != NULL);
+          }
+
+          pushfrontNodeInEntryList(pNewEntry, pNext);
+        } else {
+          pNode = pNext;
+        }
+      }
+
+      if (pe->num == 0) {
+        assert(pe->next == NULL);
+      } else {
+        assert(pe->next != NULL);
+      }
+
+    }
+
   }
 
-//  uDebug("hash table resize completed, new capacity:%d, load factor:%f, elapsed time:%fms", pHashObj->capacity,
-//         ((double)pHashObj->size) / pHashObj->capacity, (et - st) / 1000.0);
+  int64_t et = taosGetTimestampUs();
+
+  uDebug("hash table resize completed, new capacity:%"PRId64", load factor:%f, elapsed time:%fms", pHashObj->capacity,
+           ((double)pHashObj->size) / pHashObj->capacity, (et - st) / 1000.0);
 }
 
 SHashNode *doCreateHashNode(const void *key, size_t keyLen, const void *pData, size_t dsize, uint32_t hashVal) {
-  size_t totalSize = dsize + sizeof(SHashNode) + keyLen;
-  
-  SHashNode *pNewNode = calloc(1, totalSize);
+  SHashNode *pNewNode = calloc(1, sizeof(SHashNode));
+
   if (pNewNode == NULL) {
     uError("failed to allocate memory, reason:%s", strerror(errno));
     return NULL;
   }
-  
+
+  pNewNode->data = malloc(dsize + keyLen);
   memcpy(pNewNode->data, pData, dsize);
-  
+
   pNewNode->key = pNewNode->data + dsize;
   memcpy(pNewNode->key, key, keyLen);
-  pNewNode->keyLen = (uint32_t)keyLen;
-  
+
+  pNewNode->keyLen = keyLen;
   pNewNode->hashVal = hashVal;
   return pNewNode;
 }
 
-SHashNode *doUpdateHashNode(SHashNode *pNode, const void *key, size_t keyLen, const void *pData, size_t dsize) {
-  size_t size = dsize + sizeof(SHashNode) + keyLen;
-  
-  SHashNode *pNewNode = (SHashNode *)realloc(pNode, size);
-  if (pNewNode == NULL) {
-    return NULL;
-  }
-  
-  memcpy(pNewNode->data, pData, dsize);
-  
-  pNewNode->key = pNewNode->data + dsize;
-  assert(memcmp(pNewNode->key, key, keyLen) == 0 && keyLen == pNewNode->keyLen);
-  
-  memcpy(pNewNode->key, key, keyLen);
-  return pNewNode;
-}
+void pushfrontNodeInEntryList(SHashEntry *pEntry, SHashNode *pNode) {
+  assert(pNode != NULL && pEntry != NULL);
 
-void doAddToHashTable(SHashObj *pHashObj, SHashNode *pNode) {
-  assert(pNode != NULL);
-  
-  int32_t index = HASH_INDEX(pNode->hashVal, pHashObj->capacity);
-  
-  SHashNode* pEntry = pHashObj->hashList[index];
-  if (pEntry != NULL) {
-    pEntry->prev = pNode;
-    
-    pNode->next = pEntry;
-    pNode->prev = NULL;
-  }
-  
-  pHashObj->hashList[index] = pNode;
-  pHashObj->size++;
+  pNode->next = pEntry->next;
+  pEntry->next = pNode;
+
+  pEntry->num += 1;
 }
 
 SHashNode *getNextHashNode(SHashMutableIterator *pIter) {
   assert(pIter != NULL);
-  
+
   pIter->entryIndex++;
-  while (pIter->entryIndex < pIter->pHashObj->capacity) {
-    SHashNode *pNode = pIter->pHashObj->hashList[pIter->entryIndex];
-    if (pNode == NULL) {
+  SHashNode *p = NULL;
+
+  while (pIter->entryIndex < pIter->numOfEntries) {
+    SHashEntry *pEntry = pIter->pHashObj->hashList[pIter->entryIndex];
+    if (pEntry->num == 0) {
       pIter->entryIndex++;
       continue;
     }
-    
-    return pNode;
+
+    if (pIter->pHashObj->type == HASH_ENTRY_LOCK) {
+      taosRLockLatch(&pEntry->latch);
+    }
+
+    p = pEntry->next;
+
+    if (pIter->pHashObj->type == HASH_ENTRY_LOCK) {
+      taosRUnLockLatch(&pEntry->latch);
+    }
+
+    return p;
   }
-  
+
   return NULL;
 }
diff --git a/src/util/src/tcache.c b/src/util/src/tcache.c
index 7eca3b2637..54a4b289b7 100644
--- a/src/util/src/tcache.c
+++ b/src/util/src/tcache.c
@@ -30,14 +30,6 @@ static FORCE_INLINE void __cache_wr_lock(SCacheObj *pCacheObj) {
 #endif
 }
 
-static FORCE_INLINE void __cache_rd_lock(SCacheObj *pCacheObj) {
-#if defined(LINUX)
-  pthread_rwlock_rdlock(&pCacheObj->lock);
-#else
-  pthread_mutex_lock(&pCacheObj->lock);
-#endif
-}
-
 static FORCE_INLINE void __cache_unlock(SCacheObj *pCacheObj) {
 #if defined(LINUX)
   pthread_rwlock_unlock(&pCacheObj->lock);
@@ -62,13 +54,6 @@ static FORCE_INLINE void __cache_lock_destroy(SCacheObj *pCacheObj) {
 #endif
 }
 
-#if 0
-static FORCE_INLINE void taosFreeNode(void *data) {
-  SCacheDataNode *pNode = *(SCacheDataNode **)data;
-  free(pNode);
-}
-#endif
-
 /**
  * @param key      key of object for hash, usually a null-terminated string
  * @param keyLen   length of key
@@ -88,13 +73,6 @@ static SCacheDataNode *taosCreateCacheNode(const char *key, size_t keyLen, const
  */
 static void taosAddToTrash(SCacheObj *pCacheObj, SCacheDataNode *pNode);
 
-/**
- * remove node in trash can
- * @param pCacheObj 
- * @param pElem 
- */
-static void taosRemoveFromTrashCan(SCacheObj *pCacheObj, STrashElem *pElem);
-
 /**
  * remove nodes in trash with refCount == 0 in cache
  * @param pNode
@@ -107,111 +85,54 @@ static void taosTrashCanEmpty(SCacheObj *pCacheObj, bool force);
 /**
  * release node
  * @param pCacheObj      cache object
- * @param pNode     data node
+ * @param pNode          data node
  */
 static FORCE_INLINE void taosCacheReleaseNode(SCacheObj *pCacheObj, SCacheDataNode *pNode) {
   if (pNode->signature != (uint64_t)pNode) {
     uError("key:%s, %p data is invalid, or has been released", pNode->key, pNode);
+    assert(0);
     return;
   }
-  
-  taosHashRemove(pCacheObj->pHashTable, pNode->key, pNode->keySize);
 
   pCacheObj->totalSize -= pNode->size;
-  uDebug("cache:%s, key:%p, %p is destroyed from cache, totalNum:%d totalSize:%" PRId64 "bytes size:%dbytes",
-         pCacheObj->name, pNode->key, pNode->data, (int32_t)taosHashGetSize(pCacheObj->pHashTable), pCacheObj->totalSize,
-         pNode->size);
+  int32_t size = taosHashGetSize(pCacheObj->pHashTable);
+  assert(size > 0);
+
+  uDebug("cache:%s, key:%p, %p is destroyed from cache, size:%dbytes, num:%d size:%" PRId64 "bytes",
+         pCacheObj->name, pNode->key, pNode->data, pNode->size, size - 1, pCacheObj->totalSize);
+
+  if (pCacheObj->freeFp) {
+    pCacheObj->freeFp(pNode->data);
+  }
 
-  if (pCacheObj->freeFp) pCacheObj->freeFp(pNode->data);
   free(pNode);
 }
 
-/**
- * move the old node into trash
- * @param pCacheObj
- * @param pNode
- */
-static FORCE_INLINE void taosCacheMoveToTrash(SCacheObj *pCacheObj, SCacheDataNode *pNode) {
-  taosHashRemove(pCacheObj->pHashTable, pNode->key, pNode->keySize);
-  taosAddToTrash(pCacheObj, pNode);
+static FORCE_INLINE void doRemoveElemInTrashcan(SCacheObj* pCacheObj, STrashElem *pElem) {
+  if (pElem->pData->signature != (uint64_t) pElem->pData) {
+    uError("key:sig:0x%" PRIx64 " %p data has been released, ignore", pElem->pData->signature, pElem->pData);
+    return;
+  }
+
+  pCacheObj->numOfElemsInTrash--;
+  if (pElem->prev) {
+    pElem->prev->next = pElem->next;
+  } else { // pnode is the header, update header
+    pCacheObj->pTrash = pElem->next;
+  }
+
+  if (pElem->next) {
+    pElem->next->prev = pElem->prev;
+  }
 }
 
-/**
- * update data in cache
- * @param pCacheObj
- * @param pNode
- * @param key
- * @param keyLen
- * @param pData
- * @param dataSize
- * @return
- */
-static SCacheDataNode *taosUpdateCacheImpl(SCacheObj *pCacheObj, SCacheDataNode *pNode, const char *key, int32_t keyLen,
-                                           const void *pData, uint32_t dataSize, uint64_t duration) {
-  SCacheDataNode *pNewNode = NULL;
-  
-  // only a node is not referenced by any other object, in-place update it
-  if (T_REF_VAL_GET(pNode) == 0) {
-    size_t newSize = sizeof(SCacheDataNode) + dataSize + keyLen + 1;
-    
-    pNewNode = (SCacheDataNode *)realloc(pNode, newSize);
-    if (pNewNode == NULL) {
-      return NULL;
-    }
-    
-    memset(pNewNode, 0, newSize);
-    pNewNode->signature = (uint64_t)pNewNode;
-    memcpy(pNewNode->data, pData, dataSize);
-    
-    pNewNode->key = (char *)pNewNode + sizeof(SCacheDataNode) + dataSize;
-    pNewNode->keySize = keyLen;
-    memcpy(pNewNode->key, key, keyLen);
-    
-    // update the timestamp information for updated key/value
-    pNewNode->addedTime = taosGetTimestampMs();
-    pNewNode->lifespan = duration;
-    
-    T_REF_INC(pNewNode);
-    
-    // the address of this node may be changed, so the prev and next element should update the corresponding pointer
-    taosHashPut(pCacheObj->pHashTable, key, keyLen, &pNewNode, sizeof(void *));
-  } else {
-    taosCacheMoveToTrash(pCacheObj, pNode);
-    
-    pNewNode = taosCreateCacheNode(key, keyLen, pData, dataSize, duration);
-    if (pNewNode == NULL) {
-      return NULL;
-    }
-    
-    T_REF_INC(pNewNode);
-    
-    // addedTime new element to hashtable
-    taosHashPut(pCacheObj->pHashTable, key, keyLen, &pNewNode, sizeof(void *));
+static FORCE_INLINE void doDestroyTrashcanElem(SCacheObj* pCacheObj, STrashElem *pElem) {
+  if (pCacheObj->freeFp) {
+    pCacheObj->freeFp(pElem->pData->data);
   }
-  
-  return pNewNode;
-}
 
-/**
- * addedTime data into hash table
- * @param key
- * @param pData
- * @param size
- * @param pCacheObj
- * @param keyLen
- * @param pNode
- * @return
- */
-static FORCE_INLINE SCacheDataNode *taosAddToCacheImpl(SCacheObj *pCacheObj, const char *key, size_t keyLen, const void *pData,
-                                                       size_t dataSize, uint64_t duration) {
-  SCacheDataNode *pNode = taosCreateCacheNode(key, keyLen, pData, dataSize, duration);
-  if (pNode == NULL) {
-    return NULL;
-  }
-  
-  T_REF_INC(pNode);
-  taosHashPut(pCacheObj->pHashTable, key, keyLen, &pNode, sizeof(void *));
-  return pNode;
+  free(pElem->pData);
+  free(pElem);
 }
 
 /**
@@ -237,7 +158,7 @@ SCacheObj *taosCacheInit(int32_t keyType, int64_t refreshTimeInSeconds, bool ext
     return NULL;
   }
   
-  pCacheObj->pHashTable = taosHashInit(128, taosGetDefaultHashFunction(keyType), false);
+  pCacheObj->pHashTable = taosHashInit(4096, taosGetDefaultHashFunction(keyType), false, HASH_ENTRY_LOCK);
   pCacheObj->name = strdup(cacheName);
   if (pCacheObj->pHashTable == NULL) {
     free(pCacheObj);
@@ -269,36 +190,74 @@ SCacheObj *taosCacheInit(int32_t keyType, int64_t refreshTimeInSeconds, bool ext
 }
 
 void *taosCachePut(SCacheObj *pCacheObj, const void *key, size_t keyLen, const void *pData, size_t dataSize, int duration) {
-  SCacheDataNode *pNode;
-  
   if (pCacheObj == NULL || pCacheObj->pHashTable == NULL) {
     return NULL;
   }
 
-  __cache_wr_lock(pCacheObj);
-  SCacheDataNode **pt = (SCacheDataNode **)taosHashGet(pCacheObj->pHashTable, key, keyLen);
-  SCacheDataNode * pOld = (pt != NULL) ? (*pt) : NULL;
-  
-  if (pOld == NULL) {  // do addedTime to cache
-    pNode = taosAddToCacheImpl(pCacheObj, key, keyLen, pData, dataSize, duration * 1000L);
-    if (NULL != pNode) {
-      pCacheObj->totalSize += pNode->size;
-
-      uDebug("cache:%s, key:%p, %p added into cache, added:%" PRIu64 ", expire:%" PRIu64 ", totalNum:%d totalSize:%" PRId64
-             "bytes size:%" PRId64 "bytes",
-             pCacheObj->name, key, pNode->data, pNode->addedTime, pNode->expireTime,
-             (int32_t)taosHashGetSize(pCacheObj->pHashTable), pCacheObj->totalSize, (int64_t)dataSize);
-    } else {
-      uError("cache:%s, key:%p, failed to added into cache, out of memory", pCacheObj->name, key);
-    }
-  } else {  // old data exists, update the node
-    pNode = taosUpdateCacheImpl(pCacheObj, pOld, key, (int32_t)keyLen, pData, (uint32_t)dataSize, duration * 1000L);
-    uDebug("cache:%s, key:%p, %p exist in cache, updated old:%p", pCacheObj->name, key, pNode->data, pOld);
+  SCacheDataNode *pNode1 = taosCreateCacheNode(key, keyLen, pData, dataSize, duration);
+  if (pNode1 == NULL) {
+    uError("cache:%s, key:%p, failed to added into cache, out of memory", pCacheObj->name, key);
+    return NULL;
   }
 
-  __cache_unlock(pCacheObj);
+  T_REF_INC(pNode1);
 
-  return (pNode != NULL) ? pNode->data : NULL;
+  int32_t succ = taosHashPut(pCacheObj->pHashTable, key, keyLen, &pNode1, sizeof(void *));
+  if (succ == 0) {
+    atomic_add_fetch_64(&pCacheObj->totalSize, pNode1->size);
+    uDebug("cache:%s, key:%p, %p added into cache, added:%" PRIu64 ", expire:%" PRIu64
+           ", totalNum:%d totalSize:%" PRId64 "bytes size:%" PRId64 "bytes",
+           pCacheObj->name, key, pNode1->data, pNode1->addedTime, pNode1->expireTime,
+           (int32_t)taosHashGetSize(pCacheObj->pHashTable), pCacheObj->totalSize, (int64_t)dataSize);
+  } else {  // duplicated key exists
+    while (1) {
+      SCacheDataNode* p = NULL;
+      int32_t ret = taosHashRemoveWithData(pCacheObj->pHashTable, key, keyLen, (void*) &p, sizeof(void*));
+
+      // add to trashcan
+      if (ret == 0) {
+        if (T_REF_VAL_GET(p) == 0) {
+          if (pCacheObj->freeFp) {
+            pCacheObj->freeFp(p->data);
+          }
+
+          taosTFree(p);
+        } else {
+          taosAddToTrash(pCacheObj, p);
+          uDebug("cache:%s, key:%p, %p exist in cache, updated old:%p", pCacheObj->name, key, pNode1->data, p);
+        }
+      }
+
+      assert(T_REF_VAL_GET(pNode1) == 1);
+
+      ret = taosHashPut(pCacheObj->pHashTable, key, keyLen, &pNode1, sizeof(void *));
+      if (ret == 0) {
+        atomic_add_fetch_64(&pCacheObj->totalSize, pNode1->size);
+
+        uDebug("cache:%s, key:%p, %p added into cache, added:%" PRIu64 ", expire:%" PRIu64
+               ", totalNum:%d totalSize:%" PRId64 "bytes size:%" PRId64 "bytes",
+               pCacheObj->name, key, pNode1->data, pNode1->addedTime, pNode1->expireTime,
+               (int32_t)taosHashGetSize(pCacheObj->pHashTable), pCacheObj->totalSize, (int64_t)dataSize);
+
+        return pNode1->data;
+
+      } else {
+        // failed, try again
+      }
+    }
+  }
+
+  return pNode1->data;
+}
+
+static void incRefFn(void* ptNode) {
+  assert(ptNode != NULL);
+
+  SCacheDataNode** p = (SCacheDataNode**) ptNode;
+  assert(T_REF_VAL_GET(*p) >= 0);
+
+  int32_t ret = T_REF_INC(*p);
+  assert(ret > 0);
 }
 
 void *taosCacheAcquireByKey(SCacheObj *pCacheObj, const void *key, size_t keyLen) {
@@ -306,23 +265,12 @@ void *taosCacheAcquireByKey(SCacheObj *pCacheObj, const void *key, size_t keyLen
     return NULL;
   }
 
-  void *pData = NULL;
-
-  __cache_rd_lock(pCacheObj);
-
-  SCacheDataNode **ptNode = (SCacheDataNode **)taosHashGet(pCacheObj->pHashTable, key, keyLen);
-
-  int32_t ref = 0;
-  if (ptNode != NULL) {
-    ref = T_REF_INC(*ptNode);
-    pData = (*ptNode)->data;
-  }
-
-  __cache_unlock(pCacheObj);
+  SCacheDataNode **ptNode = (SCacheDataNode **)taosHashGetCB(pCacheObj->pHashTable, key, keyLen, incRefFn);
+  void* pData = (ptNode != NULL)? (*ptNode)->data:NULL;
 
   if (pData != NULL) {
     atomic_add_fetch_32(&pCacheObj->statistics.hitCount, 1);
-    uDebug("cache:%s, key:%p, %p is retrieved from cache, refcnt:%d", pCacheObj->name, key, pData, ref);
+    uDebug("cache:%s, key:%p, %p is retrieved from cache, refcnt:%d", pCacheObj->name, key, pData, T_REF_VAL_GET(*ptNode));
   } else {
     atomic_add_fetch_32(&pCacheObj->statistics.missCount, 1);
     uDebug("cache:%s, key:%p, not in cache, retrieved failed", pCacheObj->name, key);
@@ -332,34 +280,6 @@ void *taosCacheAcquireByKey(SCacheObj *pCacheObj, const void *key, size_t keyLen
   return pData;
 }
 
-void* taosCacheUpdateExpireTimeByName(SCacheObj *pCacheObj, void *key, size_t keyLen, uint64_t expireTime) {
-  if (pCacheObj == NULL || taosHashGetSize(pCacheObj->pHashTable) == 0) {
-    return NULL;
-  }
-
-  __cache_rd_lock(pCacheObj);
-  
-  SCacheDataNode **ptNode = (SCacheDataNode **)taosHashGet(pCacheObj->pHashTable, key, keyLen);
-  if (ptNode != NULL) {
-     T_REF_INC(*ptNode);
-    (*ptNode)->expireTime = expireTime; // taosGetTimestampMs() + (*ptNode)->lifespan;
-  }
-
-  __cache_unlock(pCacheObj);
-
-  if (ptNode != NULL) {
-    atomic_add_fetch_32(&pCacheObj->statistics.hitCount, 1);
-    uDebug("cache:%s, key:%p, %p expireTime is updated in cache, refcnt:%d", pCacheObj->name, key,
-        (*ptNode)->data, T_REF_VAL_GET(*ptNode));
-  } else {
-    atomic_add_fetch_32(&pCacheObj->statistics.missCount, 1);
-    uDebug("cache:%s, key:%p, not in cache, retrieved failed", pCacheObj->name, key);
-  }
-
-  atomic_add_fetch_32(&pCacheObj->statistics.totalAccess, 1);
-  return (ptNode != NULL) ? (*ptNode)->data : NULL;
-}
-
 void *taosCacheAcquireByData(SCacheObj *pCacheObj, void *data) {
   if (pCacheObj == NULL || data == NULL) return NULL;
   
@@ -420,15 +340,16 @@ void taosCacheRelease(SCacheObj *pCacheObj, void **data, bool _remove) {
 
   if (pCacheObj->extendLifespan && (!inTrashCan) && (!_remove)) {
     atomic_store_64(&pNode->expireTime, pNode->lifespan + taosGetTimestampMs());
-    uDebug("cache:%s data:%p extend life time to %"PRId64 "  before release", pCacheObj->name, pNode->data, pNode->expireTime);
+    uDebug("cache:%s data:%p extend expire time: %"PRId64, pCacheObj->name, pNode->data, pNode->expireTime);
   }
 
   if (_remove) {
-    __cache_wr_lock(pCacheObj);
-
     // NOTE: once refcount is decrease, pNode may be freed by other thread immediately.
-    int32_t ref = T_REF_DEC(pNode);
-    uDebug("cache:%s, key:%p, %p is released, refcnt:%d", pCacheObj->name, pNode->key, pNode->data, ref);
+    char* key = pNode->key;
+    char* d = pNode->data;
+
+    int32_t ref = T_REF_VAL_GET(pNode);
+    uDebug("cache:%s, key:%p, %p is released, refcnt:%d", pCacheObj->name, key, d, ref - 1);
 
     /*
      * If it is not referenced by other users, remove it immediately. Otherwise move this node to trashcan wait for all users
@@ -437,50 +358,85 @@ void taosCacheRelease(SCacheObj *pCacheObj, void **data, bool _remove) {
      * NOTE: previous ref is 0, and current ref is still 0, remove it. If previous is not 0, there is another thread
      * that tries to do the same thing.
      */
-    if (pNode->inTrashCan) {
+    if (inTrashCan) {
+      ref = T_REF_DEC(pNode);
+
       if (ref == 0) {
         assert(pNode->pTNodeHeader->pData == pNode);
-        taosRemoveFromTrashCan(pCacheObj, pNode->pTNodeHeader);
+
+        __cache_wr_lock(pCacheObj);
+        doRemoveElemInTrashcan(pCacheObj, pNode->pTNodeHeader);
+        __cache_unlock(pCacheObj);
+
+        doDestroyTrashcanElem(pCacheObj, pNode->pTNodeHeader);
       }
     } else {
-      if (ref > 0) {
-        assert(pNode->pTNodeHeader == NULL);
-        taosCacheMoveToTrash(pCacheObj, pNode);
-      } else {
-        taosCacheReleaseNode(pCacheObj, pNode);
+      // NOTE: remove it from hash in the first place, otherwise, the pNode may have been released by other thread
+      // when reaches here.
+      int32_t ret = taosHashRemove(pCacheObj->pHashTable, pNode->key, pNode->keySize);
+      ref = T_REF_DEC(pNode);
+
+      // successfully remove from hash table, if failed, this node must have been move to trash already, do nothing.
+      // note that the remove operation can be executed only once.
+      if (ret == 0) {
+        if (ref > 0) {
+          assert(pNode->pTNodeHeader == NULL);
+
+          __cache_wr_lock(pCacheObj);
+          taosAddToTrash(pCacheObj, pNode);
+          __cache_unlock(pCacheObj);
+        } else {  // ref == 0
+          atomic_sub_fetch_64(&pCacheObj->totalSize, pNode->size);
+
+          int32_t size = taosHashGetSize(pCacheObj->pHashTable);
+          uDebug("cache:%s, key:%p, %p is destroyed from cache, size:%dbytes, num:%d size:%" PRId64 "bytes",
+                 pCacheObj->name, pNode->key, pNode->data, pNode->size, size, pCacheObj->totalSize);
+
+          if (pCacheObj->freeFp) {
+            pCacheObj->freeFp(pNode->data);
+          }
+
+          free(pNode);
+        }
       }
     }
 
-    __cache_unlock(pCacheObj);
-
   } else {
     // NOTE: once refcount is decrease, pNode may be freed by other thread immediately.
-    int32_t ref = T_REF_DEC(pNode);
+    char* key = pNode->key;
+    char* p = pNode->data;
 
-    uDebug("cache:%s, key:%p, %p released, refcnt:%d, data in trancan:%d", pCacheObj->name, pNode->key, pNode->data,
-           ref, inTrashCan);
+    int32_t ref = T_REF_DEC(pNode);
+    uDebug("cache:%s, key:%p, %p released, refcnt:%d, data in trancan:%d", pCacheObj->name, key, p, ref, inTrashCan);
   }
 }
 
-void taosCacheEmpty(SCacheObj *pCacheObj) {
-  SHashMutableIterator *pIter = taosHashCreateIter(pCacheObj->pHashTable);
-  
-  __cache_wr_lock(pCacheObj);
-  while (taosHashIterNext(pIter)) {
-    if (pCacheObj->deleting == 1) {
-      break;
-    }
-    
-    SCacheDataNode *pNode = *(SCacheDataNode **) taosHashIterGet(pIter);
-    if (T_REF_VAL_GET(pNode) == 0) {
-      taosCacheReleaseNode(pCacheObj, pNode);
-    } else {
-      taosCacheMoveToTrash(pCacheObj, pNode);
-    }
+typedef struct SHashTravSupp {
+  SCacheObj* pCacheObj;
+  int64_t    time;
+  __cache_free_fn_t fp;
+} SHashTravSupp;
+
+static bool travHashTableEmptyFn(void* param, void* data) {
+  SHashTravSupp* ps = (SHashTravSupp*) param;
+  SCacheObj* pCacheObj= ps->pCacheObj;
+
+  SCacheDataNode *pNode = *(SCacheDataNode **) data;
+
+  if (T_REF_VAL_GET(pNode) == 0) {
+    taosCacheReleaseNode(pCacheObj, pNode);
+  } else { // do add to trashcan
+    taosAddToTrash(pCacheObj, pNode);
   }
-  __cache_unlock(pCacheObj);
-  
-  taosHashDestroyIter(pIter);
+
+  // this node should be remove from hash table
+  return false;
+}
+
+void taosCacheEmpty(SCacheObj *pCacheObj) {
+  SHashTravSupp sup = {.pCacheObj = pCacheObj, .fp = NULL, .time = taosGetTimestampMs()};
+
+  taosHashCondTraverse(pCacheObj->pHashTable, travHashTableEmptyFn, &sup);
   taosTrashCanEmpty(pCacheObj, false);
 }
 
@@ -496,8 +452,7 @@ void taosCacheCleanup(SCacheObj *pCacheObj) {
   doCleanupDataCache(pCacheObj);
 }
 
-SCacheDataNode *taosCreateCacheNode(const char *key, size_t keyLen, const char *pData, size_t size,
-                                           uint64_t duration) {
+SCacheDataNode *taosCreateCacheNode(const char *key, size_t keyLen, const char *pData, size_t size, uint64_t duration) {
   size_t totalSize = size + sizeof(SCacheDataNode) + keyLen;
 
   SCacheDataNode *pNewNode = calloc(1, totalSize);
@@ -543,36 +498,10 @@ void taosAddToTrash(SCacheObj *pCacheObj, SCacheDataNode *pNode) {
   pNode->pTNodeHeader = pElem;
   pCacheObj->numOfElemsInTrash++;
 
-  uDebug("key:%p, %p move to trash, numOfElem in trash:%d", pNode->key, pNode->data, pCacheObj->numOfElemsInTrash);
+  uDebug("%s key:%p, %p move to trash, numOfElem in trash:%d", pCacheObj->name, pNode->key, pNode->data,
+      pCacheObj->numOfElemsInTrash);
 }
 
-void taosRemoveFromTrashCan(SCacheObj *pCacheObj, STrashElem *pElem) {
-  if (pElem->pData->signature != (uint64_t)pElem->pData) {
-    uError("key:sig:0x%" PRIx64 " %p data has been released, ignore", pElem->pData->signature, pElem->pData);
-    return;
-  }
-
-  pCacheObj->numOfElemsInTrash--;
-  if (pElem->prev) {
-    pElem->prev->next = pElem->next;
-  } else { /* pnode is the header, update header */
-    pCacheObj->pTrash = pElem->next;
-  }
-
-  if (pElem->next) {
-    pElem->next->prev = pElem->prev;
-  }
-
-  pElem->pData->signature = 0;
-  if (pCacheObj->freeFp) {
-    pCacheObj->freeFp(pElem->pData->data);
-  }
-
-  free(pElem->pData);
-  free(pElem);
-}
-
-// TODO add another lock when scanning trashcan
 void taosTrashCanEmpty(SCacheObj *pCacheObj, bool force) {
   __cache_wr_lock(pCacheObj);
 
@@ -580,8 +509,8 @@ void taosTrashCanEmpty(SCacheObj *pCacheObj, bool force) {
     if (pCacheObj->pTrash != NULL) {
       uError("key:inconsistency data in cache, numOfElem in trash:%d", pCacheObj->numOfElemsInTrash);
     }
-    pCacheObj->pTrash = NULL;
 
+    pCacheObj->pTrash = NULL;
     __cache_unlock(pCacheObj);
     return;
   }
@@ -597,10 +526,12 @@ void taosTrashCanEmpty(SCacheObj *pCacheObj, bool force) {
     if (force || (T_REF_VAL_GET(pElem->pData) == 0)) {
       uDebug("key:%p, %p removed from trash. numOfElem in trash:%d", pElem->pData->key, pElem->pData->data,
              pCacheObj->numOfElemsInTrash - 1);
-      STrashElem *p = pElem;
 
+      STrashElem *p = pElem;
       pElem = pElem->next;
-      taosRemoveFromTrashCan(pCacheObj, p);
+
+      doRemoveElemInTrashcan(pCacheObj, p);
+      doDestroyTrashcanElem(pCacheObj, p);
     } else {
       pElem = pElem->next;
     }
@@ -610,27 +541,13 @@ void taosTrashCanEmpty(SCacheObj *pCacheObj, bool force) {
 }
 
 void doCleanupDataCache(SCacheObj *pCacheObj) {
-  __cache_wr_lock(pCacheObj);
-
-  SHashMutableIterator *pIter = taosHashCreateIter(pCacheObj->pHashTable);
-  while (taosHashIterNext(pIter)) {
-    SCacheDataNode *pNode = *(SCacheDataNode **)taosHashIterGet(pIter);
-
-    int32_t c = T_REF_VAL_GET(pNode);
-    if (c <= 0) {
-      taosCacheReleaseNode(pCacheObj, pNode);
-    } else {
-      uDebug("cache:%s key:%p, %p will not remove from cache, refcnt:%d", pCacheObj->name, pNode->key,
-          pNode->data, T_REF_VAL_GET(pNode));
-    }
-  }
-  taosHashDestroyIter(pIter);
+  SHashTravSupp sup = {.pCacheObj = pCacheObj, .fp = NULL, .time = taosGetTimestampMs()};
+  taosHashCondTraverse(pCacheObj->pHashTable, travHashTableEmptyFn, &sup);
 
   // todo memory leak if there are object with refcount greater than 0 in hash table?
   taosHashCleanup(pCacheObj->pHashTable);
-  __cache_unlock(pCacheObj);
-
   taosTrashCanEmpty(pCacheObj, true);
+
   __cache_lock_destroy(pCacheObj);
   
   taosTFree(pCacheObj->name);
@@ -638,26 +555,31 @@ void doCleanupDataCache(SCacheObj *pCacheObj) {
   free(pCacheObj);
 }
 
-static void doCacheRefresh(SCacheObj* pCacheObj, int64_t time, __cache_free_fn_t fp) {
-  SHashMutableIterator *pIter = taosHashCreateIter(pCacheObj->pHashTable);
+bool travHashTableFn(void* param, void* data) {
+  SHashTravSupp* ps = (SHashTravSupp*) param;
+  SCacheObj*     pCacheObj= ps->pCacheObj;
 
-  __cache_wr_lock(pCacheObj);
-  while (taosHashIterNext(pIter)) {
-    SCacheDataNode *pNode = *(SCacheDataNode **)taosHashIterGet(pIter);
+  SCacheDataNode* pNode = *(SCacheDataNode **) data;
+  if (pNode->expireTime < ps->time && T_REF_VAL_GET(pNode) <= 0) {
+    taosCacheReleaseNode(pCacheObj, pNode);
 
-    if (pNode->expireTime < (uint64_t)time && T_REF_VAL_GET(pNode) <= 0) {
-      taosCacheReleaseNode(pCacheObj, pNode);
-      continue;
-    }
-
-    if (fp) {
-      fp(pNode->data);
-    }
+    // this node should be remove from hash table
+    return false;
   }
 
-  __cache_unlock(pCacheObj);
+  if (ps->fp) {
+    (ps->fp)(pNode->data);
+  }
 
-  taosHashDestroyIter(pIter);
+  // do not remove element in hash table
+  return true;
+}
+
+static void doCacheRefresh(SCacheObj* pCacheObj, int64_t time, __cache_free_fn_t fp) {
+  assert(pCacheObj != NULL);
+
+  SHashTravSupp sup = {.pCacheObj = pCacheObj, .fp = fp, .time = time};
+  taosHashCondTraverse(pCacheObj->pHashTable, travHashTableFn, &sup);
 }
 
 void* taosCacheTimedRefresh(void *handle) {
diff --git a/src/util/src/tkvstore.c b/src/util/src/tkvstore.c
index 9657d82773..c026aed5f2 100644
--- a/src/util/src/tkvstore.c
+++ b/src/util/src/tkvstore.c
@@ -433,7 +433,7 @@ static SKVStore *tdNewKVStore(char *fname, iterFunc iFunc, afterFunc aFunc, void
   pStore->iFunc = iFunc;
   pStore->aFunc = aFunc;
   pStore->appH = appH;
-  pStore->map = taosHashInit(4096, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BIGINT), false);
+  pStore->map = taosHashInit(4096, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BIGINT), true, false);
   if (pStore->map == NULL) {
     terrno = TSDB_CODE_COM_OUT_OF_MEMORY;
     goto _err;
diff --git a/src/util/tests/CMakeLists.txt b/src/util/tests/CMakeLists.txt
index 8687a8005d..09523cbfb4 100644
--- a/src/util/tests/CMakeLists.txt
+++ b/src/util/tests/CMakeLists.txt
@@ -10,6 +10,6 @@ IF (HEADER_GTEST_INCLUDE_DIR AND LIB_GTEST_STATIC_DIR)
     INCLUDE_DIRECTORIES(${HEADER_GTEST_INCLUDE_DIR})
     AUX_SOURCE_DIRECTORY(${CMAKE_CURRENT_SOURCE_DIR} SOURCE_LIST)
 
-    ADD_EXECUTABLE(utilTest ${SOURCE_LIST})
+    ADD_EXECUTABLE(utilTest ./cacheTest.cpp ./hashTest.cpp)
     TARGET_LINK_LIBRARIES(utilTest tutil common osdetail gtest pthread gcov)
 ENDIF()
diff --git a/src/util/tests/hashTest.cpp b/src/util/tests/hashTest.cpp
index f9f636db90..bc3fed74c4 100644
--- a/src/util/tests/hashTest.cpp
+++ b/src/util/tests/hashTest.cpp
@@ -10,7 +10,7 @@
 namespace {
 // the simple test code for basic operations
 void simpleTest() {
-  auto* hashTable = (SHashObj*) taosHashInit(64, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), false);
+  SHashObj* hashTable = (SHashObj*) taosHashInit(64, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), false, HASH_ENTRY_LOCK);
   ASSERT_EQ(taosHashGetSize(hashTable), 0);
   
   // put 400 elements in the hash table
@@ -47,7 +47,7 @@ void simpleTest() {
 }
 
 void stringKeyTest() {
-  auto* hashTable = (SHashObj*) taosHashInit(64, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BINARY), false);
+  auto* hashTable = (SHashObj*) taosHashInit(64, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BINARY), false, HASH_ENTRY_LOCK);
   ASSERT_EQ(taosHashGetSize(hashTable), 0);
   
   char key[128] = {0};
@@ -97,7 +97,7 @@ void functionTest() {
  * a single threads situation
  */
 void noLockPerformanceTest() {
-  auto* hashTable = (SHashObj*) taosHashInit(4096, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BINARY), false);
+  auto* hashTable = (SHashObj*) taosHashInit(4096, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BINARY), false, HASH_ENTRY_LOCK);
   ASSERT_EQ(taosHashGetSize(hashTable), 0);
   
   char key[128] = {0};
diff --git a/src/vnode/src/vnodeMain.c b/src/vnode/src/vnodeMain.c
index 9695f90c30..a576d43cda 100644
--- a/src/vnode/src/vnodeMain.c
+++ b/src/vnode/src/vnodeMain.c
@@ -50,7 +50,7 @@ int32_t vnodeInitResources() {
   vnodeInitWriteFp();
   vnodeInitReadFp();
 
-  tsDnodeVnodesHash = taosHashInit(TSDB_MIN_VNODES, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), true);
+  tsDnodeVnodesHash = taosHashInit(TSDB_MIN_VNODES, taosGetDefaultHashFunction(TSDB_DATA_TYPE_INT), true, true);
   if (tsDnodeVnodesHash == NULL) {
     vError("failed to init vnode list");
     return TSDB_CODE_VND_OUT_OF_MEMORY;
diff --git a/src/vnode/src/vnodeRead.c b/src/vnode/src/vnodeRead.c
index 066770e1bb..8ca76ef22d 100644
--- a/src/vnode/src/vnodeRead.c
+++ b/src/vnode/src/vnodeRead.c
@@ -14,7 +14,7 @@
  */
 
 #define _DEFAULT_SOURCE
-#include <dnode.h>
+//#include <dnode.h>
 #include "os.h"
 
 #include "tglobal.h"
@@ -66,7 +66,7 @@ int32_t vnodeProcessRead(void *param, SReadMsg *pReadMsg) {
   return (*vnodeProcessReadMsgFp[msgType])(pVnode, pReadMsg);
 }
 
-static void vnodePutItemIntoReadQueue(SVnodeObj *pVnode, void *qhandle) {
+static void vnodePutItemIntoReadQueue(SVnodeObj *pVnode, void **qhandle) {
   SReadMsg *pRead = (SReadMsg *)taosAllocateQitem(sizeof(SReadMsg));
   pRead->rpcMsg.msgType = TSDB_MSG_TYPE_QUERY;
   pRead->pCont = qhandle;
@@ -74,22 +74,23 @@ static void vnodePutItemIntoReadQueue(SVnodeObj *pVnode, void *qhandle) {
   pRead->rpcMsg.handle = NULL;
 
   atomic_add_fetch_32(&pVnode->refCount, 1);
+
+  vDebug("QInfo:%p add to vread queue for exec query, msg:%p", *qhandle, pRead);
   taosWriteQitem(pVnode->rqueue, TAOS_QTYPE_QUERY, pRead);
 }
 
-static int32_t vnodeDumpQueryResult(SRspRet *pRet, void* pVnode, void* handle, bool* freeHandle) {
+static int32_t vnodeDumpQueryResult(SRspRet *pRet, void* pVnode, void** handle, bool* freeHandle) {
   bool continueExec = false;
 
   int32_t code = TSDB_CODE_SUCCESS;
-  if ((code = qDumpRetrieveResult(handle, (SRetrieveTableRsp **)&pRet->rsp, &pRet->len, &continueExec)) == TSDB_CODE_SUCCESS) {
+  if ((code = qDumpRetrieveResult(*handle, (SRetrieveTableRsp **)&pRet->rsp, &pRet->len, &continueExec)) == TSDB_CODE_SUCCESS) {
     if (continueExec) {
-      vDebug("QInfo:%p add to query task queue for exec", handle);
-      vnodePutItemIntoReadQueue(pVnode, handle);
-      pRet->qhandle = handle;
       *freeHandle = false;
+      vnodePutItemIntoReadQueue(pVnode, handle);
+      pRet->qhandle = *handle;
     } else {
-      vDebug("QInfo:%p exec completed", handle);
       *freeHandle = true;
+      vDebug("QInfo:%p exec completed, free handle:%d", *handle, *freeHandle);
     }
   } else {
     pRet->rsp = (SRetrieveTableRsp *)rpcMallocCont(sizeof(SRetrieveTableRsp));
@@ -158,7 +159,7 @@ static int32_t vnodeProcessQueryMsg(SVnodeObj *pVnode, SReadMsg *pReadMsg) {
     // current connect is broken
     if (code == TSDB_CODE_SUCCESS) {
       handle = qRegisterQInfo(pVnode->qMgmt, (uint64_t) pQInfo);
-      if (handle == NULL) {  // failed to register qhandle
+      if (handle == NULL) {  // failed to register qhandle, todo add error test case
         vError("vgId:%d QInfo:%p register qhandle failed, return to app, code:%s", pVnode->vgId, (void *)pQInfo,
                tstrerror(pRsp->code));
         pRsp->code = TSDB_CODE_QRY_INVALID_QHANDLE;
@@ -179,41 +180,40 @@ static int32_t vnodeProcessQueryMsg(SVnodeObj *pVnode, SReadMsg *pReadMsg) {
     }
 
     if (handle != NULL) {
-      vDebug("vgId:%d, QInfo:%p, dnode query msg disposed, register qhandle and return to app", vgId, *handle);
-
-      vnodePutItemIntoReadQueue(pVnode, *handle);
-      qReleaseQInfo(pVnode->qMgmt, (void**) &handle, false);
+      vDebug("vgId:%d, QInfo:%p, dnode query msg disposed, create qhandle and returns to app", vgId, *handle);
+      vnodePutItemIntoReadQueue(pVnode, handle);
     }
-
   } else {
     assert(pCont != NULL);
+    void** qhandle = (void**) pCont;
 
-    handle = qAcquireQInfo(pVnode->qMgmt, (uint64_t) pCont);
-    if (handle == NULL) {
-      vWarn("QInfo:%p invalid qhandle in continuing exec query, conn:%p", (void*) pCont, pReadMsg->rpcMsg.handle);
-      code = TSDB_CODE_QRY_INVALID_QHANDLE;
-    } else {
-      vDebug("vgId:%d, QInfo:%p, dnode continue exec query", pVnode->vgId, (void*) pCont);
+    vDebug("vgId:%d, QInfo:%p, dnode continues to exec query", pVnode->vgId, *qhandle);
 
-      bool freehandle = false;
-      bool buildRes = qTableQuery(*handle); // do execute query
+    bool freehandle = false;
+    bool buildRes = qTableQuery(*qhandle); // do execute query
 
-      // build query rsp
-      if (buildRes) {
-        // update the connection info according to the retrieve connection
-        pReadMsg->rpcMsg.handle = qGetResultRetrieveMsg(*handle);
-        assert(pReadMsg->rpcMsg.handle != NULL);
+    // build query rsp, the retrieve request has reached here already
+    if (buildRes) {
+      // update the connection info according to the retrieve connection
+      pReadMsg->rpcMsg.handle = qGetResultRetrieveMsg(*qhandle);
+      assert(pReadMsg->rpcMsg.handle != NULL);
 
-        vDebug("vgId:%d, QInfo:%p, start to build result rsp after query paused, %p", pVnode->vgId, *handle, pReadMsg->rpcMsg.handle);
-        code = vnodeDumpQueryResult(&pReadMsg->rspRet, pVnode, *handle, &freehandle);
+      vDebug("vgId:%d, QInfo:%p, start to build retrieval rsp after query paused, %p", pVnode->vgId, *qhandle,
+             pReadMsg->rpcMsg.handle);
+      code = vnodeDumpQueryResult(&pReadMsg->rspRet, pVnode, qhandle, &freehandle);
 
-        // todo test the error code case
-        if (code == TSDB_CODE_SUCCESS) {
-          code = TSDB_CODE_QRY_HAS_RSP;
-        }
+      // todo test the error code case
+      if (code == TSDB_CODE_SUCCESS) {
+        code = TSDB_CODE_QRY_HAS_RSP;
       }
+    } else {
+      freehandle = qQueryCompleted(*qhandle);
+    }
 
-      qReleaseQInfo(pVnode->qMgmt, (void**) &handle, freehandle);
+    // NOTE: if the qhandle is not put into vread queue or query is completed, free the qhandle.
+    // if not build result, free it not by forced.
+    if (freehandle || (!buildRes)) {
+      qReleaseQInfo(pVnode->qMgmt, (void **)&qhandle, freehandle);
     }
   }
 
@@ -225,8 +225,8 @@ static int32_t vnodeProcessFetchMsg(SVnodeObj *pVnode, SReadMsg *pReadMsg) {
   SRspRet *pRet = &pReadMsg->rspRet;
 
   SRetrieveTableMsg *pRetrieve = pCont;
-  pRetrieve->qhandle = htobe64(pRetrieve->qhandle);
   pRetrieve->free = htons(pRetrieve->free);
+  pRetrieve->qhandle = htobe64(pRetrieve->qhandle);
 
   vDebug("vgId:%d, QInfo:%p, retrieve msg is disposed, free:%d, conn:%p", pVnode->vgId, (void*) pRetrieve->qhandle, pRetrieve->free, pReadMsg->rpcMsg.handle);
 
@@ -236,18 +236,27 @@ static int32_t vnodeProcessFetchMsg(SVnodeObj *pVnode, SReadMsg *pReadMsg) {
   void** handle = qAcquireQInfo(pVnode->qMgmt, pRetrieve->qhandle);
   if (handle == NULL || (*handle) != (void*) pRetrieve->qhandle) {
     code = TSDB_CODE_QRY_INVALID_QHANDLE;
-    vDebug("vgId:%d, invalid qhandle in fetch result, QInfo:%p", pVnode->vgId, (void*) pRetrieve->qhandle);
+    vDebug("vgId:%d, invalid qhandle in retrieving result, QInfo:%p", pVnode->vgId, (void*) pRetrieve->qhandle);
     
     vnodeBuildNoResultQueryRsp(pRet);
     return code;
   }
 
   if (pRetrieve->free == 1) {
-    vDebug("vgId:%d, QInfo:%p, retrieve msg received to kill query and free qhandle", pVnode->vgId, *handle);
+    vWarn("vgId:%d, QInfo:%p, retrieve msg received to kill query and free qhandle", pVnode->vgId, *handle);
     qKillQuery(*handle);
     qReleaseQInfo(pVnode->qMgmt, (void**) &handle, true);
 
     vnodeBuildNoResultQueryRsp(pRet);
+    code = TSDB_CODE_TSC_QUERY_CANCELLED;
+    return code;
+  }
+
+  // register the qhandle to connect to quit query immediate if connection is broken
+  if (vnodeNotifyCurrentQhandle(pReadMsg->rpcMsg.handle, *handle, pVnode->vgId) != TSDB_CODE_SUCCESS) {
+    vError("vgId:%d, QInfo:%p, retrieve discarded since link is broken, %p", pVnode->vgId, *handle, pReadMsg->rpcMsg.handle);
+    code = TSDB_CODE_RPC_NETWORK_UNAVAIL;
+    qReleaseQInfo(pVnode->qMgmt, (void**) &handle, true);
     return code;
   }
 
@@ -259,16 +268,22 @@ static int32_t vnodeProcessFetchMsg(SVnodeObj *pVnode, SReadMsg *pReadMsg) {
     //TODO handle malloc failure
     pRet->rsp = (SRetrieveTableRsp *)rpcMallocCont(sizeof(SRetrieveTableRsp));
     memset(pRet->rsp, 0, sizeof(SRetrieveTableRsp));
+    freeHandle = true;
   } else { // result is not ready, return immediately
     if (!buildRes) {
       qReleaseQInfo(pVnode->qMgmt, (void**) &handle, false);
       return TSDB_CODE_QRY_NOT_READY;
     }
 
-    code = vnodeDumpQueryResult(pRet, pVnode, *handle, &freeHandle);
+    code = vnodeDumpQueryResult(pRet, pVnode, handle, &freeHandle);
+  }
+
+  // If qhandle is not added into vread queue, the query should be completed already or paused with error.
+  // Here free qhandle immediately
+  if (freeHandle) {
+    qReleaseQInfo(pVnode->qMgmt, (void**) &handle, true);
   }
 
-  qReleaseQInfo(pVnode->qMgmt, (void**) &handle, freeHandle);
   return code;
 }
 
diff --git a/tests/script/general/parser/join.sim b/tests/script/general/parser/join.sim
index 07f2cd3f77..882f561ae1 100644
--- a/tests/script/general/parser/join.sim
+++ b/tests/script/general/parser/join.sim
@@ -257,6 +257,21 @@ if $data01 != $val then
   return -1
 endi
 
+sql select count(join_tb1.*) + count(join_tb0.*) from join_tb1 , join_tb0 where join_tb1.ts = join_tb0.ts and join_tb1.ts >= 100000 and join_tb0.c7 = false;;
+if $rows != 1 then
+  return -1
+endi
+
+if $data00 != 20.000000000 then
+  print expect 20.000000000 actual $data00
+  return -1
+endi
+
+sql select count(join_tb1.*)/10 from join_tb1 , join_tb0 where join_tb1.ts = join_tb0.ts and join_tb1.ts >= 100000 and join_tb0.c7 = false;;
+if $data00 != 1.000000000 then
+  return -1
+endi
+
 print 3
 #agg + where condition
 sql select count(join_tb1.c3), count(join_tb0.ts) from $tb1 , $tb2 where $ts1 = $ts2 and join_tb1.ts <= 100002 and join_tb0.c7 = true;
@@ -381,6 +396,15 @@ if $data00 != $val then
   return -1
 endi
 
+sql select sum(join_mt0.c1)+sum(join_mt0.c1) from join_mt0, join_mt1 where join_mt0.ts = join_mt1.ts and join_mt0.t1=join_mt1.t1 and join_mt0.c2=99 and join_mt1.ts=100999;
+if $rows != 1 then
+  return -1
+endi
+
+if $data00 != 396.000000000 then
+  return -1
+endi
+
 # first/last
 sql select count(join_mt0.c1), sum(join_mt1.c2), first(join_mt0.c5), last(join_mt1.c7) from join_mt0, join_mt1 where join_mt0.t1=join_mt1.t1 and join_mt0.ts=join_mt1.ts and join_mt0.t1=1 interval(10a) order by join_mt0.ts asc;
 
diff --git a/tests/script/general/parser/sliding.sim b/tests/script/general/parser/sliding.sim
index 177c95651f..f85211beb8 100644
--- a/tests/script/general/parser/sliding.sim
+++ b/tests/script/general/parser/sliding.sim
@@ -1,7 +1,7 @@
 system sh/stop_dnodes.sh
 
 system sh/deploy.sh -n dnode1 -i 1
-system sh/cfg.sh -n dnode1 -c walLevel -v 0
+system sh/cfg.sh -n dnode1 -c walLevel -v 1
 system sh/cfg.sh -n dnode1 -c debugFlag -v 135
 system sh/cfg.sh -n dnode1 -c rpcDebugFlag -v 135
 system sh/exec.sh -n dnode1 -s start
@@ -28,7 +28,7 @@ $mt = $mtPrefix . $i
 
 sql drop database if exits $db -x step1
 step1:
-sql create database if not exists $db tables 4 keep 36500
+sql create database if not exists $db maxtables 4 keep 36500
 sql use $db
 sql create table $mt (ts timestamp, c1 int, c2 float, c3 bigint, c4 smallint, c5 tinyint, c6 double, c7 bool, c8 binary(10), c9 nchar(9)) TAGS(t1 int, t2 binary(12))
 
diff --git a/tests/script/general/parser/testSuite.sim b/tests/script/general/parser/testSuite.sim
index 1e73893793..dd4faee959 100644
--- a/tests/script/general/parser/testSuite.sim
+++ b/tests/script/general/parser/testSuite.sim
@@ -1,27 +1,27 @@
-sleep 2000
-run general/parser/alter.sim
-sleep 2000
-run general/parser/alter1.sim
-sleep 2000
-run general/parser/alter_stable.sim
-sleep 2000
-run general/parser/auto_create_tb.sim
-sleep 2000
-run general/parser/auto_create_tb_drop_tb.sim
-sleep 2000
-run general/parser/col_arithmetic_operation.sim
-sleep 2000
-run general/parser/columnValue.sim
-sleep 2000
-run general/parser/commit.sim
-sleep 2000
-run general/parser/create_db.sim
-sleep 2000
-run general/parser/create_mt.sim
-sleep 2000
-run general/parser/create_tb.sim
-sleep 2000
-run general/parser/dbtbnameValidate.sim
+#sleep 2000
+#run general/parser/alter.sim
+#sleep 2000
+#run general/parser/alter1.sim
+#sleep 2000
+#run general/parser/alter_stable.sim
+#sleep 2000
+#run general/parser/auto_create_tb.sim
+#sleep 2000
+#run general/parser/auto_create_tb_drop_tb.sim
+#sleep 2000
+#run general/parser/col_arithmetic_operation.sim
+#sleep 2000
+#run general/parser/columnValue.sim
+#sleep 2000
+#run general/parser/commit.sim
+#sleep 2000
+#run general/parser/create_db.sim
+#sleep 2000
+#run general/parser/create_mt.sim
+#sleep 2000
+#run general/parser/create_tb.sim
+#sleep 2000
+#run general/parser/dbtbnameValidate.sim
 sleep 2000
 run general/parser/fill.sim
 sleep 2000
diff --git a/tests/script/general/parser/topbot.sim b/tests/script/general/parser/topbot.sim
index a0c46dbc65..fdda79451d 100644
--- a/tests/script/general/parser/topbot.sim
+++ b/tests/script/general/parser/topbot.sim
@@ -66,9 +66,56 @@ if $row != 100 then
   return -1
 endi
 
-sql select last(c2) from tb_tb9
+sql select bottom(c1, 100) from tb_stb0
+if $row != 100 then
+  return -1
+endi
+
+sql select last(*) from tb_tb9
 if $row != 1 then
   return -1
 endi
 
+sql select last(c2) from tb_tb9
+if $row != 0 then
+  return -1
+endi
+
+sql select first(c2), last(c2) from tb_tb9
+if $row != 0 then
+  return -1
+endi
+
+sql create table test(ts timestamp, col1 tinyint, col2 smallint, col3 int, col4 bigint, col5 float, col6 double, col7 bool, col8 binary(20), col9 nchar(20)) tags(loc nchar(20));
+sql create table test1 using test tags('beijing');
+sql insert into test1 values(1537146000000, 1, 1, 1, 1, 0.100000, 0.100000, 0, 'taosdata1', '涛思数据1');
+sql insert into test1 values(1537146000001, 2, 2, 2, 2, 1.100000, 1.100000, 1, 'taosdata2', '涛思数据2');
+sql insert into test1 values(1537146000002, 3, 3, 3, 3, 2.100000, 2.100000, 0, 'taosdata3', '涛思数据3');
+sql insert into test1 values(1537146000003, 4, 4, 4, 4, 3.100000, 3.100000, 1, 'taosdata4', '涛思数据4');
+sql insert into test1 values(1537146000004, 5, 5, 5, 5, 4.100000, 4.100000, 0, 'taosdata5', '涛思数据5');
+sql insert into test1 values(1537146000005, 6, 6, 6, 6, 5.100000, 5.100000, 1, 'taosdata6', '涛思数据6');
+sql insert into test1 values(1537146000006, 7, 7, 7, 7, 6.100000, 6.100000, 0, 'taosdata7', '涛思数据7');
+sql insert into test1 values(1537146000007, 8, 8, 8, 8, 7.100000, 7.100000, 1, 'taosdata8', '涛思数据8');
+sql insert into test1 values(1537146000008, 9, 9, 9, 9, 8.100000, 8.100000, 0, 'taosdata9', '涛思数据9');
+sql insert into test1 values(1537146000009, 10, 10, 10, 10, 9.100000, 9.100000, 1, 'taosdata10', '涛思数据10');
+sql select bottom(col5, 10) from test
+if $rows != 10 then
+  return -1
+endi
+
+if $data01 != 0.10000 then
+  print expect 0.10000 actual: $data01
+  return -1
+endi
+
+if $data11 != 1.10000 then
+  print expect 1.10000 actual: $data11
+  return -1
+endi
+
+if $data21 != 2.10000 then
+  print expect 2.10000 actual: $data21
+  return -1
+endi
+
 system sh/exec.sh -n dnode1 -s stop -x SIGINT
\ No newline at end of file
diff --git a/tests/script/general/parser/union.sim b/tests/script/general/parser/union.sim
index 358bcb8a40..fbd1c211b9 100644
--- a/tests/script/general/parser/union.sim
+++ b/tests/script/general/parser/union.sim
@@ -1,10 +1,10 @@
-#system sh/stop_dnodes.sh
-#
-#system sh/deploy.sh -n dnode1 -i 1
-#system sh/cfg.sh -n dnode1 -c walLevel -v 0
-#system sh/cfg.sh -n dnode1 -c debugFlag -v 135
-#system sh/cfg.sh -n dnode1 -c rpcDebugFlag -v 135
-#system sh/exec.sh -n dnode1 -s start
+system sh/stop_dnodes.sh
+
+system sh/deploy.sh -n dnode1 -i 1
+system sh/cfg.sh -n dnode1 -c walLevel -v 0
+system sh/cfg.sh -n dnode1 -c debugFlag -v 135
+system sh/cfg.sh -n dnode1 -c rpcDebugFlag -v 135
+system sh/exec.sh -n dnode1 -s start
 sleep 1000
 sql connect
 
@@ -24,77 +24,77 @@ $mt = $mtPrefix . $i
 $j = 1
 
 $mt1 = $mtPrefix . $j
-#
-#sql drop database if exits $db -x step1
-#step1:
-#sql create database if not exists $db maxtables 4
+
+sql drop database if exits $db -x step1
+step1:
+sql create database if not exists $db maxtables 4
 sql use $db
-#sql create table $mt (ts timestamp, c1 int, c2 float, c3 bigint, c4 smallint, c5 tinyint, c6 double, c7 bool, c8 binary(10), c9 nchar(9)) TAGS(t1 int)
-#
-#$i = 0
-#$t = 1578203484000
-#
-#while $i < $tbNum
-#  $tb = $tbPrefix . $i
-#  sql create table $tb using $mt tags( $i )
-#
-#  $x = 0
-#  while $x < $rowNum
-#    $ms = $x * 1000
-#    $ms = $ms * 60
-#
-#    $c = $x / 100
-#    $c = $c * 100
-#    $c = $x - $c
-#    $binary = 'binary . $c
-#    $binary = $binary . '
-#    $nchar = 'nchar . $c
-#    $nchar = $nchar . '
-#
-#    $t1 = $t + $ms
-#    sql insert into $tb values ($t1 , $c , $c , $c , $c , $c , $c , $c , $binary , $nchar )
-#    $x = $x + 1
-#  endw
-#
-#  $i = $i + 1
-#endw
-#
-#sql create table $mt1 (ts timestamp, c1 int, c2 float, c3 bigint, c4 smallint, c5 tinyint, c6 double, c7 bool, c8 binary(10), c9 nchar(9)) TAGS(t1 int)
-#
-#$j = 0
-#$t = 1578203484000
-#$rowNum = 1000
-#$tbNum = 5
-#$i = 0
-#
-#while $i < $tbNum
-#  $tb1 = $tbPrefix1 . $j
-#  sql create table $tb1 using $mt1 tags( $i )
-#
-#  $x = 0
-#  while $x < $rowNum
-#    $ms = $x * 1000
-#    $ms = $ms * 60
-#
-#    $c = $x / 100
-#    $c = $c * 100
-#    $c = $x - $c
-#    $binary = 'binary . $c
-#    $binary = $binary . '
-#    $nchar = 'nchar . $c
-#    $nchar = $nchar . '
-#
-#    $t1 = $t + $ms
-#    sql insert into $tb1 values ($t1 , $c , $c , $c , $c , $c , $c , $c , $binary , $nchar )
-#    $x = $x + 1
-#  endw
-#
-#  $i = $i + 1
-#  $j = $j + 1
-#endw
-#
-#print sleep 1sec.
-#sleep 1000
+sql create table $mt (ts timestamp, c1 int, c2 float, c3 bigint, c4 smallint, c5 tinyint, c6 double, c7 bool, c8 binary(10), c9 nchar(9)) TAGS(t1 int)
+
+$i = 0
+$t = 1578203484000
+
+while $i < $tbNum
+  $tb = $tbPrefix . $i
+  sql create table $tb using $mt tags( $i )
+
+  $x = 0
+  while $x < $rowNum
+    $ms = $x * 1000
+    $ms = $ms * 60
+
+    $c = $x / 100
+    $c = $c * 100
+    $c = $x - $c
+    $binary = 'binary . $c
+    $binary = $binary . '
+    $nchar = 'nchar . $c
+    $nchar = $nchar . '
+
+    $t1 = $t + $ms
+    sql insert into $tb values ($t1 , $c , $c , $c , $c , $c , $c , $c , $binary , $nchar )
+    $x = $x + 1
+  endw
+
+  $i = $i + 1
+endw
+
+sql create table $mt1 (ts timestamp, c1 int, c2 float, c3 bigint, c4 smallint, c5 tinyint, c6 double, c7 bool, c8 binary(10), c9 nchar(9)) TAGS(t1 int)
+
+$j = 0
+$t = 1578203484000
+$rowNum = 1000
+$tbNum = 5
+$i = 0
+
+while $i < $tbNum
+  $tb1 = $tbPrefix1 . $j
+  sql create table $tb1 using $mt1 tags( $i )
+
+  $x = 0
+  while $x < $rowNum
+    $ms = $x * 1000
+    $ms = $ms * 60
+
+    $c = $x / 100
+    $c = $c * 100
+    $c = $x - $c
+    $binary = 'binary . $c
+    $binary = $binary . '
+    $nchar = 'nchar . $c
+    $nchar = $nchar . '
+
+    $t1 = $t + $ms
+    sql insert into $tb1 values ($t1 , $c , $c , $c , $c , $c , $c , $c , $binary , $nchar )
+    $x = $x + 1
+  endw
+
+  $i = $i + 1
+  $j = $j + 1
+endw
+
+print sleep 1sec.
+sleep 1000
 
 $i = 1
 $tb = $tbPrefix . $i
@@ -412,4 +412,8 @@ if $data10 != @union_db0@ then
   return -1
 endi
 
+sql_error show tables union all show tables
+sql_error show stables union all show stables
+sql_error show databases union all show databases
+
 system sh/exec.sh -n dnode1 -s stop -x SIGINT
\ No newline at end of file