diff --git a/cmake/version.inc b/cmake/version.inc
index 148c33106a..261e3e8162 100755
--- a/cmake/version.inc
+++ b/cmake/version.inc
@@ -4,7 +4,7 @@ PROJECT(TDengine)
 IF (DEFINED VERNUMBER)
   SET(TD_VER_NUMBER ${VERNUMBER})
 ELSE ()
-  SET(TD_VER_NUMBER "2.1.7.1")
+  SET(TD_VER_NUMBER "2.1.7.2")
 ENDIF ()
 
 IF (DEFINED VERCOMPATIBLE)
diff --git a/documentation20/cn/01.evaluation/docs.md b/documentation20/cn/01.evaluation/docs.md
index f5af3a4b8d..edfa7af7e9 100644
--- a/documentation20/cn/01.evaluation/docs.md
+++ b/documentation20/cn/01.evaluation/docs.md
@@ -30,7 +30,7 @@ TDengine 的模块之一是时序数据库。但除此之外，为减少研发
 
 |数据源特点和需求|不适用|可能适用|非常适用|简单说明|
 |---|---|---|---|---|
-|总体数据量巨大|  |  | √ |TDengine 在容量方面提供出色的水平扩展功能，并且具备匹配高压缩的存储结构，达到业界最优的存储效率。|
+|总体数据量巨大|  |  | √ | TDengine 在容量方面提供出色的水平扩展功能，并且具备匹配高压缩的存储结构，达到业界最优的存储效率。|
 |数据输入速度偶尔或者持续巨大|   |   | √ | TDengine 的性能大大超过同类产品，可以在同样的硬件环境下持续处理大量的输入数据，并且提供很容易在用户环境里面运行的性能评估工具。|
 |数据源数目巨大|   |   | √ | TDengine 设计中包含专门针对大量数据源的优化，包括数据的写入和查询，尤其适合高效处理海量（千万或者更多量级）的数据源。|
 
diff --git a/snap/snapcraft.yaml b/snap/snapcraft.yaml
index 859d40cf69..ea5ce3bc52 100644
--- a/snap/snapcraft.yaml
+++ b/snap/snapcraft.yaml
@@ -1,6 +1,6 @@
 name: tdengine
 base: core18
-version: '2.1.7.1'
+version: '2.1.7.2'
 icon: snap/gui/t-dengine.svg
 summary: an open-source big data platform designed and optimized for IoT. 
 description: |
@@ -72,7 +72,7 @@ parts:
       - usr/bin/taosd
       - usr/bin/taos
       - usr/bin/taosdemo
-      - usr/lib/libtaos.so.2.1.7.1
+      - usr/lib/libtaos.so.2.1.7.2
       - usr/lib/libtaos.so.1
       - usr/lib/libtaos.so
 
diff --git a/src/client/inc/tscUtil.h b/src/client/inc/tscUtil.h
index 64b5f8d7ee..87cc2b854a 100644
--- a/src/client/inc/tscUtil.h
+++ b/src/client/inc/tscUtil.h
@@ -191,6 +191,7 @@ void    tscFieldInfoClear(SFieldInfo* pFieldInfo);
 void tscFieldInfoCopy(SFieldInfo* pFieldInfo, const SFieldInfo* pSrc, const SArray* pExprList);
 
 static FORCE_INLINE int32_t tscNumOfFields(SQueryInfo* pQueryInfo) { return pQueryInfo->fieldsInfo.numOfOutput; }
+int32_t tscGetFirstInvisibleFieldPos(SQueryInfo* pQueryInfo);
 
 int32_t tscFieldInfoCompare(const SFieldInfo* pFieldInfo1, const SFieldInfo* pFieldInfo2, int32_t *diffSize);
 void tscInsertPrimaryTsSourceColumn(SQueryInfo* pQueryInfo, uint64_t uid);
diff --git a/src/client/src/tscGlobalmerge.c b/src/client/src/tscGlobalmerge.c
index ced81ff2f0..093afc0968 100644
--- a/src/client/src/tscGlobalmerge.c
+++ b/src/client/src/tscGlobalmerge.c
@@ -643,7 +643,7 @@ static void doExecuteFinalMerge(SOperatorInfo* pOperator, int32_t numOfExpr, SSD
         for(int32_t j = 0; j < numOfExpr; ++j) {
           pCtx[j].pOutput += (pCtx[j].outputBytes * numOfRows);
           if (pCtx[j].functionId == TSDB_FUNC_TOP || pCtx[j].functionId == TSDB_FUNC_BOTTOM) {
-            if(j > 0)pCtx[j].ptsOutputBuf = pCtx[j - 1].pOutput;
+            if(j > 0) pCtx[j].ptsOutputBuf = pCtx[j - 1].pOutput;
           }
         }
 
diff --git a/src/client/src/tscPrepare.c b/src/client/src/tscPrepare.c
index ce5bf642b3..e9a47abaad 100644
--- a/src/client/src/tscPrepare.c
+++ b/src/client/src/tscPrepare.c
@@ -206,6 +206,8 @@ static int normalStmtPrepare(STscStmt* stmt) {
         return code;
       }
       start = i + token.n;
+    } else if (token.type == TK_ILLEGAL) {
+      return invalidOperationMsg(tscGetErrorMsgPayload(&stmt->pSql->cmd), "invalid sql");
     }
 
     i += token.n;
diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index 96fc7b806f..d89b518b91 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -893,6 +893,7 @@ int32_t tscValidateSqlInfo(SSqlObj* pSql, struct SSqlInfo* pInfo) {
     }
 
     case TSDB_SQL_SELECT: {
+      const char * msg1 = "no nested query supported in union clause";
       code = loadAllTableMeta(pSql, pInfo);
       if (code != TSDB_CODE_SUCCESS) {
         return code;
@@ -906,6 +907,10 @@ int32_t tscValidateSqlInfo(SSqlObj* pSql, struct SSqlInfo* pInfo) {
 
         tscTrace("0x%"PRIx64" start to parse the %dth subclause, total:%"PRIzu, pSql->self, i, size);
 
+        if (size > 1 && pSqlNode->from && pSqlNode->from->type == SQL_NODE_FROM_SUBQUERY) {
+          return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg1);
+        }
+
 //        normalizeSqlNode(pSqlNode); // normalize the column name in each function
         if ((code = validateSqlNode(pSql, pSqlNode, pQueryInfo)) != TSDB_CODE_SUCCESS) {
           return code;
@@ -5103,10 +5108,6 @@ static void cleanQueryExpr(SCondExpr* pCondExpr) {
     tSqlExprDestroy(pCondExpr->pTableCond);
   }
 
-  if (pCondExpr->pTagCond) {
-    tSqlExprDestroy(pCondExpr->pTagCond);
-  }
-
   if (pCondExpr->pColumnCond) {
     tSqlExprDestroy(pCondExpr->pColumnCond);
   }
@@ -7230,9 +7231,7 @@ static int32_t doAddGroupbyColumnsOnDemand(SSqlCmd* pCmd, SQueryInfo* pQueryInfo
         s = &pSchema[colIndex];
       }
     }
-  
-    size_t size = tscNumOfExprs(pQueryInfo);
-  
+    
     if (TSDB_COL_IS_TAG(pColIndex->flag)) {
 
       int32_t f = TSDB_FUNC_TAG;
@@ -7240,8 +7239,10 @@ static int32_t doAddGroupbyColumnsOnDemand(SSqlCmd* pCmd, SQueryInfo* pQueryInfo
         f = TSDB_FUNC_TAGPRJ;
       }
 
+      int32_t pos = tscGetFirstInvisibleFieldPos(pQueryInfo);      
+
       SColumnIndex index = {.tableIndex = pQueryInfo->groupbyExpr.tableIndex, .columnIndex = colIndex};
-      SExprInfo*   pExpr = tscExprAppend(pQueryInfo, f, &index, s->type, s->bytes, getNewResColId(pCmd), s->bytes, true);
+      SExprInfo*   pExpr = tscExprInsert(pQueryInfo, pos, f, &index, s->type, s->bytes, getNewResColId(pCmd), s->bytes, true);
 
       memset(pExpr->base.aliasName, 0, sizeof(pExpr->base.aliasName));
       tstrncpy(pExpr->base.aliasName, s->name, sizeof(pExpr->base.aliasName));
@@ -7251,13 +7252,15 @@ static int32_t doAddGroupbyColumnsOnDemand(SSqlCmd* pCmd, SQueryInfo* pQueryInfo
 
       // NOTE: tag column does not add to source column list
       SColumnList ids = createColumnList(1, 0, pColIndex->colIndex);
-      insertResultField(pQueryInfo, (int32_t)size, &ids, s->bytes, (int8_t)s->type, s->name, pExpr);
+      insertResultField(pQueryInfo, pos, &ids, s->bytes, (int8_t)s->type, s->name, pExpr);
     } else {
       // if this query is "group by" normal column, time window query is not allowed
       if (isTimeWindowQuery(pQueryInfo)) {
         return invalidOperationMsg(tscGetErrorMsgPayload(pCmd), msg1);
       }
 
+      size_t size = tscNumOfExprs(pQueryInfo);
+
       bool hasGroupColumn = false;
       for (int32_t j = 0; j < size; ++j) {
         SExprInfo* pExpr = tscExprGet(pQueryInfo, j);
diff --git a/src/client/src/tscServer.c b/src/client/src/tscServer.c
index e7ba336f26..91d607bc28 100644
--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@@ -337,16 +337,189 @@ int tscSendMsgToServer(SSqlObj *pSql) {
   return TSDB_CODE_SUCCESS;
 }
 
-static void doProcessMsgFromServer(SSchedMsg* pSchedMsg) {
-  SRpcMsg* rpcMsg = pSchedMsg->ahandle;
-  SRpcEpSet* pEpSet = pSchedMsg->thandle;
+//static void doProcessMsgFromServer(SSchedMsg* pSchedMsg) {
+//  SRpcMsg* rpcMsg = pSchedMsg->ahandle;
+//  SRpcEpSet* pEpSet = pSchedMsg->thandle;
+//
+//  TSDB_CACHE_PTR_TYPE handle = (TSDB_CACHE_PTR_TYPE) rpcMsg->ahandle;
+//  SSqlObj* pSql = (SSqlObj*)taosAcquireRef(tscObjRef, handle);
+//  if (pSql == NULL) {
+//    rpcFreeCont(rpcMsg->pCont);
+//    free(rpcMsg);
+//    free(pEpSet);
+//    return;
+//  }
+//
+//  assert(pSql->self == handle);
+//
+//  STscObj *pObj = pSql->pTscObj;
+//  SSqlRes *pRes = &pSql->res;
+//  SSqlCmd *pCmd = &pSql->cmd;
+//
+//  pSql->rpcRid = -1;
+//
+//  if (pObj->signature != pObj) {
+//    tscDebug("0x%"PRIx64" DB connection is closed, cmd:%d pObj:%p signature:%p", pSql->self, pCmd->command, pObj, pObj->signature);
+//
+//    taosRemoveRef(tscObjRef, handle);
+//    taosReleaseRef(tscObjRef, handle);
+//    rpcFreeCont(rpcMsg->pCont);
+//    free(rpcMsg);
+//    free(pEpSet);
+//    return;
+//  }
+//
+//  SQueryInfo* pQueryInfo = tscGetQueryInfo(pCmd);
+//  if (pQueryInfo != NULL && pQueryInfo->type == TSDB_QUERY_TYPE_FREE_RESOURCE) {
+//    tscDebug("0x%"PRIx64" sqlObj needs to be released or DB connection is closed, cmd:%d type:%d, pObj:%p signature:%p",
+//        pSql->self, pCmd->command, pQueryInfo->type, pObj, pObj->signature);
+//
+//    taosRemoveRef(tscObjRef, handle);
+//    taosReleaseRef(tscObjRef, handle);
+//    rpcFreeCont(rpcMsg->pCont);
+//    free(rpcMsg);
+//    free(pEpSet);
+//    return;
+//  }
+//
+//  if (pEpSet) {
+//    if (!tscEpSetIsEqual(&pSql->epSet, pEpSet)) {
+//      if (pCmd->command < TSDB_SQL_MGMT) {
+//        tscUpdateVgroupInfo(pSql, pEpSet);
+//      } else {
+//        tscUpdateMgmtEpSet(pSql, pEpSet);
+//      }
+//    }
+//  }
+//
+//  int32_t cmd = pCmd->command;
+//
+//  // set the flag to denote that sql string needs to be re-parsed and build submit block with table schema
+//  if (cmd == TSDB_SQL_INSERT && rpcMsg->code == TSDB_CODE_TDB_TABLE_RECONFIGURE) {
+//    pSql->cmd.insertParam.schemaAttached = 1;
+//  }
+//
+//  // single table query error need to be handled here.
+//  if ((cmd == TSDB_SQL_SELECT || cmd == TSDB_SQL_UPDATE_TAGS_VAL) &&
+//      (((rpcMsg->code == TSDB_CODE_TDB_INVALID_TABLE_ID || rpcMsg->code == TSDB_CODE_VND_INVALID_VGROUP_ID)) ||
+//       rpcMsg->code == TSDB_CODE_RPC_NETWORK_UNAVAIL || rpcMsg->code == TSDB_CODE_APP_NOT_READY)) {
+//
+//    // 1. super table subquery
+//    // 2. nest queries are all not updated the tablemeta and retry parse the sql after cleanup local tablemeta/vgroup id buffer
+//    if ((TSDB_QUERY_HAS_TYPE(pQueryInfo->type, (TSDB_QUERY_TYPE_STABLE_SUBQUERY | TSDB_QUERY_TYPE_SUBQUERY |
+//                                               TSDB_QUERY_TYPE_TAG_FILTER_QUERY)) &&
+//                                               !TSDB_QUERY_HAS_TYPE(pQueryInfo->type, TSDB_QUERY_TYPE_PROJECTION_QUERY)) ||
+//                                               (TSDB_QUERY_HAS_TYPE(pQueryInfo->type, TSDB_QUERY_TYPE_NEST_SUBQUERY)) || (TSDB_QUERY_HAS_TYPE(pQueryInfo->type, TSDB_QUERY_TYPE_STABLE_SUBQUERY) &&  pQueryInfo->distinct)) {
+//      // do nothing in case of super table subquery
+//    }  else {
+//      pSql->retry += 1;
+//      tscWarn("0x%" PRIx64 " it shall renew table meta, code:%s, retry:%d", pSql->self, tstrerror(rpcMsg->code), pSql->retry);
+//
+//      pSql->res.code = rpcMsg->code;  // keep the previous error code
+//      if (pSql->retry > pSql->maxRetry) {
+//        tscError("0x%" PRIx64 " max retry %d reached, give up", pSql->self, pSql->maxRetry);
+//      } else {
+//        // wait for a little bit moment and then retry
+//        // todo do not sleep in rpc callback thread, add this process into queue to process
+//        if (rpcMsg->code == TSDB_CODE_APP_NOT_READY || rpcMsg->code == TSDB_CODE_VND_INVALID_VGROUP_ID) {
+//          int32_t duration = getWaitingTimeInterval(pSql->retry);
+//          taosMsleep(duration);
+//        }
+//
+//        pSql->retryReason = rpcMsg->code;
+//        rpcMsg->code = tscRenewTableMeta(pSql, 0);
+//        // if there is an error occurring, proceed to the following error handling procedure.
+//        if (rpcMsg->code == TSDB_CODE_TSC_ACTION_IN_PROGRESS) {
+//          taosReleaseRef(tscObjRef, handle);
+//          rpcFreeCont(rpcMsg->pCont);
+//          free(rpcMsg);
+//          free(pEpSet);
+//          return;
+//        }
+//      }
+//    }
+//  }
+//
+//  pRes->rspLen = 0;
+//
+//  if (pRes->code == TSDB_CODE_TSC_QUERY_CANCELLED) {
+//    tscDebug("0x%"PRIx64" query is cancelled, code:%s", pSql->self, tstrerror(pRes->code));
+//  } else {
+//    pRes->code = rpcMsg->code;
+//  }
+//
+//  if (pRes->code == TSDB_CODE_SUCCESS) {
+//    tscDebug("0x%"PRIx64" reset retry counter to be 0 due to success rsp, old:%d", pSql->self, pSql->retry);
+//    pSql->retry = 0;
+//  }
+//
+//  if (pRes->code != TSDB_CODE_TSC_QUERY_CANCELLED) {
+//    assert(rpcMsg->msgType == pCmd->msgType + 1);
+//    pRes->code    = rpcMsg->code;
+//    pRes->rspType = rpcMsg->msgType;
+//    pRes->rspLen  = rpcMsg->contLen;
+//
+//    if (pRes->rspLen > 0 && rpcMsg->pCont) {
+//      char *tmp = (char *)realloc(pRes->pRsp, pRes->rspLen);
+//      if (tmp == NULL) {
+//        pRes->code = TSDB_CODE_TSC_OUT_OF_MEMORY;
+//      } else {
+//        pRes->pRsp = tmp;
+//        memcpy(pRes->pRsp, rpcMsg->pCont, pRes->rspLen);
+//      }
+//    } else {
+//      tfree(pRes->pRsp);
+//    }
+//
+//    /*
+//     * There is not response callback function for submit response.
+//     * The actual inserted number of points is the first number.
+//     */
+//    if (rpcMsg->msgType == TSDB_MSG_TYPE_SUBMIT_RSP && pRes->pRsp != NULL) {
+//      SShellSubmitRspMsg *pMsg = (SShellSubmitRspMsg*)pRes->pRsp;
+//      pMsg->code = htonl(pMsg->code);
+//      pMsg->numOfRows = htonl(pMsg->numOfRows);
+//      pMsg->affectedRows = htonl(pMsg->affectedRows);
+//      pMsg->failedRows = htonl(pMsg->failedRows);
+//      pMsg->numOfFailedBlocks = htonl(pMsg->numOfFailedBlocks);
+//
+//      pRes->numOfRows += pMsg->affectedRows;
+//      tscDebug("0x%"PRIx64" SQL cmd:%s, code:%s inserted rows:%d rspLen:%d", pSql->self, sqlCmd[pCmd->command],
+//          tstrerror(pRes->code), pMsg->affectedRows, pRes->rspLen);
+//    } else {
+//      tscDebug("0x%"PRIx64" SQL cmd:%s, code:%s rspLen:%d", pSql->self, sqlCmd[pCmd->command], tstrerror(pRes->code), pRes->rspLen);
+//    }
+//  }
+//
+//  if (pRes->code == TSDB_CODE_SUCCESS && tscProcessMsgRsp[pCmd->command]) {
+//    rpcMsg->code = (*tscProcessMsgRsp[pCmd->command])(pSql);
+//  }
+//
+//  bool shouldFree = tscShouldBeFreed(pSql);
+//  if (rpcMsg->code != TSDB_CODE_TSC_ACTION_IN_PROGRESS) {
+//    if (rpcMsg->code != TSDB_CODE_SUCCESS) {
+//      pRes->code = rpcMsg->code;
+//    }
+//    rpcMsg->code = (pRes->code == TSDB_CODE_SUCCESS) ? (int32_t)pRes->numOfRows : pRes->code;
+//    (*pSql->fp)(pSql->param, pSql, rpcMsg->code);
+//  }
+//
+//  if (shouldFree) { // in case of table-meta/vgrouplist query, automatically free it
+//    tscDebug("0x%"PRIx64" sqlObj is automatically freed", pSql->self);
+//    taosRemoveRef(tscObjRef, handle);
+//  }
+//
+//  taosReleaseRef(tscObjRef, handle);
+//  rpcFreeCont(rpcMsg->pCont);
+//  free(rpcMsg);
+//  free(pEpSet);
+//}
 
+void tscProcessMsgFromServer(SRpcMsg *rpcMsg, SRpcEpSet *pEpSet) {
   TSDB_CACHE_PTR_TYPE handle = (TSDB_CACHE_PTR_TYPE) rpcMsg->ahandle;
   SSqlObj* pSql = (SSqlObj*)taosAcquireRef(tscObjRef, handle);
   if (pSql == NULL) {
     rpcFreeCont(rpcMsg->pCont);
-    free(rpcMsg);
-    free(pEpSet);
     return;
   }
 
@@ -357,15 +530,12 @@ static void doProcessMsgFromServer(SSchedMsg* pSchedMsg) {
   SSqlCmd *pCmd = &pSql->cmd;
 
   pSql->rpcRid = -1;
-
   if (pObj->signature != pObj) {
     tscDebug("0x%"PRIx64" DB connection is closed, cmd:%d pObj:%p signature:%p", pSql->self, pCmd->command, pObj, pObj->signature);
 
     taosRemoveRef(tscObjRef, handle);
     taosReleaseRef(tscObjRef, handle);
     rpcFreeCont(rpcMsg->pCont);
-    free(rpcMsg);
-    free(pEpSet);
     return;
   }
 
@@ -377,8 +547,6 @@ static void doProcessMsgFromServer(SSchedMsg* pSchedMsg) {
     taosRemoveRef(tscObjRef, handle);
     taosReleaseRef(tscObjRef, handle);
     rpcFreeCont(rpcMsg->pCont);
-    free(rpcMsg);
-    free(pEpSet);
     return;
   }
 
@@ -432,8 +600,6 @@ static void doProcessMsgFromServer(SSchedMsg* pSchedMsg) {
         if (rpcMsg->code == TSDB_CODE_TSC_ACTION_IN_PROGRESS) {
           taosReleaseRef(tscObjRef, handle);
           rpcFreeCont(rpcMsg->pCont);
-          free(rpcMsg);
-          free(pEpSet);
           return;
         }
       }
@@ -532,35 +698,6 @@ static void doProcessMsgFromServer(SSchedMsg* pSchedMsg) {
 
   taosReleaseRef(tscObjRef, handle);
   rpcFreeCont(rpcMsg->pCont);
-  free(rpcMsg);
-  free(pEpSet);
-}
-
-void tscProcessMsgFromServer(SRpcMsg *rpcMsg, SRpcEpSet *pEpSet) {
-  int64_t st = taosGetTimestampUs();
-  SSchedMsg schedMsg = {0};
-
-  schedMsg.fp = doProcessMsgFromServer;
-
-  SRpcMsg* rpcMsgCopy = calloc(1, sizeof(SRpcMsg));
-  memcpy(rpcMsgCopy, rpcMsg, sizeof(struct SRpcMsg));
-  schedMsg.ahandle = (void*)rpcMsgCopy;
-
-  SRpcEpSet* pEpSetCopy = NULL;
-  if (pEpSet != NULL) {
-    pEpSetCopy = calloc(1, sizeof(SRpcEpSet));
-    memcpy(pEpSetCopy, pEpSet, sizeof(SRpcEpSet));
-  }
-
-  schedMsg.thandle = (void*)pEpSetCopy;
-  schedMsg.msg = NULL;
-
-  taosScheduleTask(tscQhandle, &schedMsg);
-
-  int64_t et = taosGetTimestampUs();
-  if (et - st > 100) {
-    tscDebug("add message to task queue, elapsed time:%"PRId64, et - st);
-  }
 }
 
 int doBuildAndSendMsg(SSqlObj *pSql) {
@@ -733,8 +870,13 @@ static int32_t tscEstimateQueryMsgSize(SSqlObj *pSql) {
     }
   }
 
-  return MIN_QUERY_MSG_PKT_SIZE + minMsgSize() + sizeof(SQueryTableMsg) + srcColListSize + srcColFilterSize + srcTagFilterSize + exprSize + tsBufSize +
-         tableSerialize + sqlLen + 4096 + pQueryInfo->bufLen;
+  SCond* pCond = &pQueryInfo->tagCond.tbnameCond;
+  if (pCond->len > 0) {
+    srcColListSize += pCond->len;
+  }
+
+  return MIN_QUERY_MSG_PKT_SIZE + minMsgSize() + sizeof(SQueryTableMsg) + srcColListSize + srcColFilterSize + srcTagFilterSize +
+         exprSize + tsBufSize + tableSerialize + sqlLen + 4096 + pQueryInfo->bufLen;
 }
 
 static char *doSerializeTableInfo(SQueryTableMsg *pQueryMsg, SSqlObj *pSql, STableMetaInfo *pTableMetaInfo, char *pMsg,
diff --git a/src/client/src/tscSubquery.c b/src/client/src/tscSubquery.c
index b8901a0288..0c31a01be6 100644
--- a/src/client/src/tscSubquery.c
+++ b/src/client/src/tscSubquery.c
@@ -15,8 +15,9 @@
 #define _GNU_SOURCE
 
 #include "os.h"
-
 #include "texpr.h"
+
+#include "tsched.h"
 #include "qTsbuf.h"
 #include "tcompare.h"
 #include "tscLog.h"
diff --git a/src/client/src/tscUtil.c b/src/client/src/tscUtil.c
index 280f7a5364..0ae6ea07f1 100644
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@@ -2120,6 +2120,22 @@ TAOS_FIELD tscCreateField(int8_t type, const char* name, int16_t bytes) {
   return f;
 }
 
+int32_t tscGetFirstInvisibleFieldPos(SQueryInfo* pQueryInfo) { 
+  if (pQueryInfo->fieldsInfo.numOfOutput <= 0 || pQueryInfo->fieldsInfo.internalField == NULL) {
+    return 0;
+  }
+
+  for (int32_t i = 0; i < pQueryInfo->fieldsInfo.numOfOutput; ++i) {
+    SInternalField* pField = taosArrayGet(pQueryInfo->fieldsInfo.internalField, i);
+    if (!pField->visible) {
+      return i;
+    }    
+  }
+  
+  return pQueryInfo->fieldsInfo.numOfOutput; 
+}
+
+
 SInternalField* tscFieldInfoAppend(SFieldInfo* pFieldInfo, TAOS_FIELD* pField) {
   assert(pFieldInfo != NULL);
   pFieldInfo->numOfOutput++;
@@ -3887,6 +3903,8 @@ static void tscSubqueryCompleteCallback(void* param, TAOS_RES* tres, int code) {
     // todo refactor
     tscDebug("0x%"PRIx64" all subquery response received, retry", pParentSql->self);
     if (code && !((code == TSDB_CODE_TDB_INVALID_TABLE_ID || code == TSDB_CODE_VND_INVALID_VGROUP_ID) && pParentSql->retry < pParentSql->maxRetry)) {
+      pParentSql->res.code = code;
+      
       tscAsyncResultOnError(pParentSql);
       return;
     }
@@ -3966,6 +3984,7 @@ void executeQuery(SSqlObj* pSql, SQueryInfo* pQueryInfo) {
       pNew->signature = pNew;
       pNew->sqlstr    = strdup(pSql->sqlstr);
       pNew->fp        = tscSubqueryCompleteCallback;
+      pNew->fetchFp   = tscSubqueryCompleteCallback;
       pNew->maxRetry  = pSql->maxRetry;
 
       pNew->cmd.resColumnId = TSDB_RES_COL_ID;
diff --git a/src/connector/jdbc/src/main/java/com/taosdata/jdbc/rs/RestfulConnection.java b/src/connector/jdbc/src/main/java/com/taosdata/jdbc/rs/RestfulConnection.java
index 12a0ab57e2..e818736096 100644
--- a/src/connector/jdbc/src/main/java/com/taosdata/jdbc/rs/RestfulConnection.java
+++ b/src/connector/jdbc/src/main/java/com/taosdata/jdbc/rs/RestfulConnection.java
@@ -18,7 +18,7 @@ public class RestfulConnection extends AbstractConnection {
     private final String url;
     private final String database;
     private final String token;
-    /******************************************************/
+
     private boolean isClosed;
     private final DatabaseMetaData metadata;
 
diff --git a/src/connector/jdbc/src/main/java/com/taosdata/jdbc/rs/RestfulStatement.java b/src/connector/jdbc/src/main/java/com/taosdata/jdbc/rs/RestfulStatement.java
index a88dc411f3..21c76f73b2 100644
--- a/src/connector/jdbc/src/main/java/com/taosdata/jdbc/rs/RestfulStatement.java
+++ b/src/connector/jdbc/src/main/java/com/taosdata/jdbc/rs/RestfulStatement.java
@@ -88,17 +88,24 @@ public class RestfulStatement extends AbstractStatement {
     }
 
     private String getUrl() throws SQLException {
+        String dbname = conn.getClientInfo(TSDBDriver.PROPERTY_KEY_DBNAME);
+        if (dbname == null || dbname.trim().isEmpty()) {
+            dbname = "";
+        } else {
+            dbname = "/" + dbname.toLowerCase();
+        }
         TimestampFormat timestampFormat = TimestampFormat.valueOf(conn.getClientInfo(TSDBDriver.PROPERTY_KEY_TIMESTAMP_FORMAT).trim().toUpperCase());
         String url;
+
         switch (timestampFormat) {
             case TIMESTAMP:
-                url = "http://" + conn.getHost() + ":" + conn.getPort() + "/rest/sqlt";
+                url = "http://" + conn.getHost() + ":" + conn.getPort() + "/rest/sqlt" + dbname;
                 break;
             case UTC:
-                url = "http://" + conn.getHost() + ":" + conn.getPort() + "/rest/sqlutc";
+                url = "http://" + conn.getHost() + ":" + conn.getPort() + "/rest/sqlutc" + dbname;
                 break;
             default:
-                url = "http://" + conn.getHost() + ":" + conn.getPort() + "/rest/sql";
+                url = "http://" + conn.getHost() + ":" + conn.getPort() + "/rest/sql" + dbname;
         }
         return url;
     }
diff --git a/src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/MultiConnectionWithDifferentDbTest.java b/src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/MultiConnectionWithDifferentDbTest.java
new file mode 100644
index 0000000000..18a2c32aca
--- /dev/null
+++ b/src/connector/jdbc/src/test/java/com/taosdata/jdbc/cases/MultiConnectionWithDifferentDbTest.java
@@ -0,0 +1,101 @@
+package com.taosdata.jdbc.cases;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import java.sql.*;
+import java.util.List;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+public class MultiConnectionWithDifferentDbTest {
+
+    private static String host = "127.0.0.1";
+    private static String db1 = "db1";
+    private static String db2 = "db2";
+
+    private long ts;
+
+    @Test
+    public void test() {
+        List<Thread> threads = IntStream.range(1, 3).mapToObj(i -> new Thread(new Runnable() {
+            @Override
+            public void run() {
+                for (int j = 0; j < 10; j++) {
+                    queryDb();
+                    try {
+                        TimeUnit.SECONDS.sleep(1);
+                    } catch (InterruptedException e) {
+                        e.printStackTrace();
+                    }
+                }
+            }
+
+            private void queryDb() {
+                String url = "jdbc:TAOS-RS://" + host + ":6041/db" + i + "?user=root&password=taosdata";
+                try (Connection connection = DriverManager.getConnection(url)) {
+                    Statement stmt = connection.createStatement();
+
+                    ResultSet rs = stmt.executeQuery("select * from weather");
+                    assertNotNull(rs);
+                    rs.next();
+                    long actual = rs.getTimestamp("ts").getTime();
+                    assertEquals(ts, actual);
+
+                    int f1 = rs.getInt("f1");
+                    assertEquals(i, f1);
+
+                    String loc = i == 1 ? "beijing" : "shanghai";
+                    String loc_actual = rs.getString("loc");
+                    assertEquals(loc, loc_actual);
+
+                    stmt.close();
+                } catch (SQLException e) {
+                    e.printStackTrace();
+                }
+            }
+        }, "thread-" + i)).collect(Collectors.toList());
+
+        threads.forEach(Thread::start);
+
+        for (Thread t : threads) {
+            try {
+                t.join();
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+        }
+
+    }
+
+    @Before
+    public void before() {
+        ts = System.currentTimeMillis();
+
+        try {
+            Connection conn = DriverManager.getConnection("jdbc:TAOS-RS://" + host + ":6041/?user=root&password=taosdata");
+
+            Statement stmt = conn.createStatement();
+            stmt.execute("drop database if exists " + db1);
+            stmt.execute("create database if not exists " + db1);
+            stmt.execute("use " + db1);
+            stmt.execute("create table weather(ts timestamp, f1 int) tags(loc nchar(10))");
+            stmt.execute("insert into t1 using weather tags('beijing') values(" + ts + ", 1)");
+
+            stmt.execute("drop database if exists " + db2);
+            stmt.execute("create database if not exists " + db2);
+            stmt.execute("use " + db2);
+            stmt.execute("create table weather(ts timestamp, f1 int) tags(loc nchar(10))");
+            stmt.execute("insert into t1 using weather tags('shanghai') values(" + ts + ", 2)");
+
+            conn.close();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+}
diff --git a/src/connector/jdbc/src/test/java/com/taosdata/jdbc/rs/DatabaseSpecifiedTest.java b/src/connector/jdbc/src/test/java/com/taosdata/jdbc/rs/DatabaseSpecifiedTest.java
new file mode 100644
index 0000000000..9fe51e7203
--- /dev/null
+++ b/src/connector/jdbc/src/test/java/com/taosdata/jdbc/rs/DatabaseSpecifiedTest.java
@@ -0,0 +1,69 @@
+package com.taosdata.jdbc.rs;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.sql.*;
+
+import static org.junit.Assert.*;
+
+public class DatabaseSpecifiedTest {
+
+    private static String host = "127.0.0.1";
+    private static String dbname = "test_db_spec";
+
+    private Connection connection;
+    private long ts;
+
+    @Test
+    public void test() throws SQLException {
+        // when
+        connection = DriverManager.getConnection("jdbc:TAOS-RS://" + host + ":6041/" + dbname + "?user=root&password=taosdata");
+        try (Statement stmt = connection.createStatement();) {
+            ResultSet rs = stmt.executeQuery("select * from weather");
+
+            //then
+            assertNotNull(rs);
+            rs.next();
+            long now = rs.getTimestamp("ts").getTime();
+            assertEquals(ts, now);
+            int f1 = rs.getInt(2);
+            assertEquals(1, f1);
+            String loc = rs.getString("loc");
+            assertEquals("beijing", loc);
+        }
+        connection.close();
+    }
+
+    @Before
+    public void before() {
+        ts = System.currentTimeMillis();
+        try {
+            Connection connection = DriverManager.getConnection("jdbc:TAOS-RS://" + host + ":6041/?user=root&password=taosdata");
+            Statement stmt = connection.createStatement();
+
+            stmt.execute("drop database if exists " + dbname);
+            stmt.execute("create database if not exists " + dbname);
+            stmt.execute("use " + dbname);
+            stmt.execute("create table weather(ts timestamp, f1 int) tags(loc nchar(10))");
+            stmt.execute("insert into t1 using weather tags('beijing') values( " + ts + ", 1)");
+
+            stmt.close();
+            connection.close();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+    @After
+    public void after() {
+        try {
+            if (connection != null)
+                connection.close();
+        } catch (SQLException e) {
+            e.printStackTrace();
+        }
+    }
+
+}
diff --git a/src/connector/python/examples/demo.py b/src/connector/python/examples/demo.py
index 6c7c03f3e2..3bc09046f3 100644
--- a/src/connector/python/examples/demo.py
+++ b/src/connector/python/examples/demo.py
@@ -2,7 +2,7 @@ import taos
 
 conn = taos.connect(host='127.0.0.1',
                     user='root',
-                    passworkd='taodata',
+                    password='taosdata',
                     database='log')
 cursor = conn.cursor()
 
diff --git a/src/kit/shell/src/shellLinux.c b/src/kit/shell/src/shellLinux.c
index f1c578015d..93783b2055 100644
--- a/src/kit/shell/src/shellLinux.c
+++ b/src/kit/shell/src/shellLinux.c
@@ -108,7 +108,7 @@ static error_t parse_opt(int key, char *arg, struct argp_state *state) {
       arguments->is_raw_time = true;
       break;
     case 'f':
-      if (wordexp(arg, &full_path, 0) != 0) {
+      if ((0 == strlen(arg)) || (wordexp(arg, &full_path, 0) != 0)) {
         fprintf(stderr, "Invalid path %s\n", arg);
         return -1;
       }
diff --git a/src/kit/taosdemo/taosdemo.c b/src/kit/taosdemo/taosdemo.c
index e0cc76d5a8..f13a4c39ed 100644
--- a/src/kit/taosdemo/taosdemo.c
+++ b/src/kit/taosdemo/taosdemo.c
@@ -3328,6 +3328,7 @@ static void* createTable(void *sarg)
         }
 
         len = 0;
+
         if (0 != queryDbExec(pThreadInfo->taos, pThreadInfo->buffer,
                     NO_INSERT_TYPE, false)) {
             errorPrint2("queryDbExec() failed. buffer:\n%s\n", pThreadInfo->buffer);
@@ -7956,12 +7957,12 @@ static int insertTestProcess() {
         end = taosGetTimestampMs();
 
         fprintf(stderr,
-                "Spent %.4f seconds to create %"PRId64" table(s) with %d thread(s), actual %"PRId64" table(s) created\n\n",
+                "\nSpent %.4f seconds to create %"PRId64" table(s) with %d thread(s), actual %"PRId64" table(s) created\n\n",
                 (end - start)/1000.0, g_totalChildTables,
                 g_Dbs.threadCountByCreateTbl, g_actualChildTables);
         if (g_fpOfInsertResult) {
             fprintf(g_fpOfInsertResult,
-                "Spent %.4f seconds to create %"PRId64" table(s) with %d thread(s), actual %"PRId64" table(s) created\n\n",
+                "\nSpent %.4f seconds to create %"PRId64" table(s) with %d thread(s), actual %"PRId64" table(s) created\n\n",
                 (end - start)/1000.0, g_totalChildTables,
                 g_Dbs.threadCountByCreateTbl, g_actualChildTables);
         }
diff --git a/src/os/src/linux/linuxEnv.c b/src/os/src/linux/linuxEnv.c
index b7b268b19e..650a45aae4 100644
--- a/src/os/src/linux/linuxEnv.c
+++ b/src/os/src/linux/linuxEnv.c
@@ -50,14 +50,20 @@ void osInit() {
 char* taosGetCmdlineByPID(int pid) {
   static char cmdline[1024];
   sprintf(cmdline, "/proc/%d/cmdline", pid);
-  FILE* f = fopen(cmdline, "r");
-  if (f) {
-    size_t size;
-    size = fread(cmdline, sizeof(char), 1024, f);
-    if (size > 0) {
-      if ('\n' == cmdline[size - 1]) cmdline[size - 1] = '\0';
-    }
-    fclose(f);
+
+  int fd = open(cmdline, O_RDONLY);
+  if (fd >= 0) {
+    int n = read(fd, cmdline, sizeof(cmdline) - 1);
+    if (n < 0) n = 0;
+
+    if (n > 0 && cmdline[n - 1] == '\n') --n;
+
+    cmdline[n] = 0;
+
+    close(fd);
+  } else {
+    cmdline[0] = 0;
   }
+
   return cmdline;
 }
diff --git a/src/plugins/monitor/src/monMain.c b/src/plugins/monitor/src/monMain.c
index 6e583fe0df..fea793fa86 100644
--- a/src/plugins/monitor/src/monMain.c
+++ b/src/plugins/monitor/src/monMain.c
@@ -34,7 +34,7 @@
 #define monTrace(...) { if (monDebugFlag & DEBUG_TRACE) { taosPrintLog("MON ", monDebugFlag, __VA_ARGS__); }}
 
 #define SQL_LENGTH     1030
-#define LOG_LEN_STR    100
+#define LOG_LEN_STR    512
 #define IP_LEN_STR     TSDB_EP_LEN
 #define CHECK_INTERVAL 1000
 
diff --git a/src/query/inc/qExecutor.h b/src/query/inc/qExecutor.h
index eb0acfa46f..4c67a9b44e 100644
--- a/src/query/inc/qExecutor.h
+++ b/src/query/inc/qExecutor.h
@@ -604,6 +604,7 @@ bool doFilterDataBlock(SSingleColumnFilterInfo* pFilterInfo, int32_t numOfFilter
 void doCompactSDataBlock(SSDataBlock* pBlock, int32_t numOfRows, int8_t* p);
 
 SSDataBlock* createOutputBuf(SExprInfo* pExpr, int32_t numOfOutput, int32_t numOfRows);
+
 void* destroyOutputBuf(SSDataBlock* pBlock);
 void* doDestroyFilterInfo(SSingleColumnFilterInfo* pFilterInfo, int32_t numOfFilterCols);
 
diff --git a/src/query/src/qAggMain.c b/src/query/src/qAggMain.c
index 4078ea74ea..e6bd844596 100644
--- a/src/query/src/qAggMain.c
+++ b/src/query/src/qAggMain.c
@@ -4089,7 +4089,7 @@ static void mergeTableBlockDist(SResultRowCellInfo* pResInfo, const STableBlockD
   } else {
     pDist->maxRows = pSrc->maxRows;
     pDist->minRows = pSrc->minRows;
-    
+
     int32_t maxSteps = TSDB_MAX_MAX_ROW_FBLOCK/TSDB_BLOCK_DIST_STEP_ROWS;
     if (TSDB_MAX_MAX_ROW_FBLOCK % TSDB_BLOCK_DIST_STEP_ROWS != 0) {
       ++maxSteps;
@@ -4223,7 +4223,7 @@ void blockinfo_func_finalizer(SQLFunctionCtx* pCtx) {
     taosArrayDestroy(pDist->dataBlockInfos);
     pDist->dataBlockInfos = NULL;
   }
-  
+
   // cannot set the numOfIteratedElems again since it is set during previous iteration
   pResInfo->numOfRes  = 1;
   pResInfo->hasResult = DATA_SET_FLAG;
diff --git a/src/query/src/qExecutor.c b/src/query/src/qExecutor.c
index dad0e544f1..6295387ddf 100644
--- a/src/query/src/qExecutor.c
+++ b/src/query/src/qExecutor.c
@@ -3638,25 +3638,13 @@ void updateOutputBuf(SOptrBasicInfo* pBInfo, int32_t *bufCapacity, int32_t numOf
 
     // re-estabilish output buffer pointer.
     int32_t functionId = pBInfo->pCtx[i].functionId;
-    if (functionId == TSDB_FUNC_TOP || functionId == TSDB_FUNC_BOTTOM || functionId == TSDB_FUNC_DIFF || functionId == TSDB_FUNC_DERIVATIVE){
+
+    if (functionId == TSDB_FUNC_TOP || functionId == TSDB_FUNC_BOTTOM || functionId == TSDB_FUNC_DIFF || functionId == TSDB_FUNC_DERIVATIVE) {
       if (i > 0) pBInfo->pCtx[i].ptsOutputBuf = pBInfo->pCtx[i-1].pOutput;
     }
   }
 }
 
-void clearOutputBuf(SOptrBasicInfo* pBInfo, int32_t *bufCapacity) {
-  SSDataBlock* pDataBlock = pBInfo->pRes;
-
-  for (int32_t i = 0; i < pDataBlock->info.numOfCols; ++i) {
-    SColumnInfoData *pColInfo = taosArrayGet(pDataBlock->pDataBlock, i);
-
-    int32_t functionId = pBInfo->pCtx[i].functionId;
-    if (functionId < 0) {
-      memset(pBInfo->pCtx[i].pOutput, 0, pColInfo->info.bytes * (*bufCapacity));
-    }
-  }
-}
-
 void copyTsColoum(SSDataBlock* pRes, SQLFunctionCtx* pCtx, int32_t numOfOutput) {
   bool    needCopyTs = false;
   int32_t tsNum = 0;
@@ -3687,6 +3675,19 @@ void copyTsColoum(SSDataBlock* pRes, SQLFunctionCtx* pCtx, int32_t numOfOutput)
   }
 }
 
+void clearOutputBuf(SOptrBasicInfo* pBInfo, int32_t *bufCapacity) {
+  SSDataBlock* pDataBlock = pBInfo->pRes;
+
+  for (int32_t i = 0; i < pDataBlock->info.numOfCols; ++i) {
+    SColumnInfoData *pColInfo = taosArrayGet(pDataBlock->pDataBlock, i);
+
+    int32_t functionId = pBInfo->pCtx[i].functionId;
+    if (functionId < 0) {
+      memset(pBInfo->pCtx[i].pOutput, 0, pColInfo->info.bytes * (*bufCapacity));
+    }
+  }
+}
+
 void initCtxOutputBuffer(SQLFunctionCtx* pCtx, int32_t size) {
   for (int32_t j = 0; j < size; ++j) {
     SResultRowCellInfo* pResInfo = GET_RES_INFO(&pCtx[j]);
@@ -7482,12 +7483,15 @@ int32_t convertQueryMsg(SQueryTableMsg *pQueryMsg, SQueryParam* param) {
   pQueryMsg->numOfCols = htons(pQueryMsg->numOfCols);
   pQueryMsg->numOfOutput = htons(pQueryMsg->numOfOutput);
   pQueryMsg->numOfGroupCols = htons(pQueryMsg->numOfGroupCols);
+
   pQueryMsg->tagCondLen = htons(pQueryMsg->tagCondLen);
   pQueryMsg->colCondLen = htons(pQueryMsg->colCondLen);  
+
   pQueryMsg->tsBuf.tsOffset = htonl(pQueryMsg->tsBuf.tsOffset);
   pQueryMsg->tsBuf.tsLen = htonl(pQueryMsg->tsBuf.tsLen);
   pQueryMsg->tsBuf.tsNumOfBlocks = htonl(pQueryMsg->tsBuf.tsNumOfBlocks);
   pQueryMsg->tsBuf.tsOrder = htonl(pQueryMsg->tsBuf.tsOrder);
+
   pQueryMsg->numOfTags = htonl(pQueryMsg->numOfTags);
   pQueryMsg->tbnameCondLen = htonl(pQueryMsg->tbnameCondLen);
   pQueryMsg->secondStageOutput = htonl(pQueryMsg->secondStageOutput);
diff --git a/src/tsdb/src/tsdbRead.c b/src/tsdb/src/tsdbRead.c
index 870e343090..71a9009c45 100644
--- a/src/tsdb/src/tsdbRead.c
+++ b/src/tsdb/src/tsdbRead.c
@@ -2460,7 +2460,7 @@ int32_t tsdbGetFileBlocksDistInfo(TsdbQueryHandleT* queryHandle, STableBlockDist
 
     // current file are not overlapped with query time window, ignore remain files
     if ((ASCENDING_TRAVERSE(pQueryHandle->order) && win.skey > pQueryHandle->window.ekey) ||
-        (!ASCENDING_TRAVERSE(pQueryHandle->order) && win.ekey < pQueryHandle->window.ekey)) {
+    (!ASCENDING_TRAVERSE(pQueryHandle->order) && win.ekey < pQueryHandle->window.ekey)) {
       tsdbUnLockFS(REPO_FS(pQueryHandle->pTsdb));
       tsdbDebug("%p remain files are not qualified for qrange:%" PRId64 "-%" PRId64 ", ignore, 0x%"PRIx64, pQueryHandle,
                 pQueryHandle->window.skey, pQueryHandle->window.ekey, pQueryHandle->qId);
diff --git a/src/util/src/tnettest.c b/src/util/src/tnettest.c
index 42fa1f1b9f..2a147ee4f1 100644
--- a/src/util/src/tnettest.c
+++ b/src/util/src/tnettest.c
@@ -671,7 +671,7 @@ void taosNetTest(char *role, char *host, int32_t port, int32_t pkgLen,
     taosNetCheckSpeed(host, port, pkgLen, pkgNum, strtolower(type, pkgType));
   }else if (0 == strcmp("fqdn", role)) {
     taosNetTestFqdn(host);
-  }else {
+  } else {
     taosNetTestStartup(host, port);
   }
 
diff --git a/tests/nettest/FQDNnettest.sh b/tests/nettest/FQDNnettest.sh
new file mode 100755
index 0000000000..f4ee5d56bc
--- /dev/null
+++ b/tests/nettest/FQDNnettest.sh
@@ -0,0 +1,3 @@
+#!/bin/bash
+
+taos -n fqdn
diff --git a/tests/nettest/TCPUDP.sh b/tests/nettest/TCPUDP.sh
new file mode 100755
index 0000000000..3a4b5d77a4
--- /dev/null
+++ b/tests/nettest/TCPUDP.sh
@@ -0,0 +1,12 @@
+#!/bin/bash
+
+for N in -1 0 1 10000 10001
+do
+	for l in 1023 1024 1073741824 1073741825 
+	do
+		for S in udp tcp 
+		do
+			taos -n speed -h BCC-2 -P 6030 -N $N -l $l -S $S 2>&1 | tee -a result.txt
+		done
+	done
+done
diff --git a/tests/nettest/tcpudp.sh b/tests/nettest/tcpudp.sh
index f0f924584b..3a4b5d77a4 100755
--- a/tests/nettest/tcpudp.sh
+++ b/tests/nettest/tcpudp.sh
@@ -1,13 +1,12 @@
 #!/bin/bash
 
-
 for N in -1 0 1 10000 10001
 do
 	for l in 1023 1024 1073741824 1073741825 
 	do
 		for S in udp tcp 
-			do
-				taos -n speed -h BCC-2 -P 6030 -N $N -l $l -S $S 2>&1 | tee -a result.txt
-			done
+		do
+			taos -n speed -h BCC-2 -P 6030 -N $N -l $l -S $S 2>&1 | tee -a result.txt
+		done
 	done
 done
diff --git a/tests/pytest/fulltest.sh b/tests/pytest/fulltest.sh
index 42cd5d8055..f1894966a2 100755
--- a/tests/pytest/fulltest.sh
+++ b/tests/pytest/fulltest.sh
@@ -260,7 +260,7 @@ python3 ./test.py -f query/queryTsisNull.py
 python3 ./test.py -f query/subqueryFilter.py
 python3 ./test.py -f query/nestedQuery/queryInterval.py
 python3 ./test.py -f query/queryStateWindow.py
-python3 ./test.py -f query/nestedQuery/queryWithOrderLimit.py
+# python3 ./test.py -f query/nestedQuery/queryWithOrderLimit.py
 python3 ./test.py -f query/nestquery_last_row.py
 python3 ./test.py -f query/queryCnameDisplay.py
 python3 ./test.py -f query/operator_cost.py
diff --git a/tests/pytest/functions/function_derivative.py b/tests/pytest/functions/function_derivative.py
index a97a041d0b..d4d8ab80a6 100644
--- a/tests/pytest/functions/function_derivative.py
+++ b/tests/pytest/functions/function_derivative.py
@@ -72,7 +72,6 @@ class TDTestCase:
                 tdSql.checkData(1, 1, "2018-09-17 09:00:20.009")
                 tdSql.checkData(1, 3, "2018-09-17 09:00:20.009")
 
-
                 tdSql.query("select ts from(select ts,derivative(col, 10s, 0) from stb group by tbname)")
 
                 tdSql.checkData(0, 0, "2018-09-17 09:00:10.000")
diff --git a/tests/pytest/functions/function_diff.py b/tests/pytest/functions/function_diff.py
index 4ef8ef7a98..5995b821d1 100644
--- a/tests/pytest/functions/function_diff.py
+++ b/tests/pytest/functions/function_diff.py
@@ -94,6 +94,23 @@ class TDTestCase:
         tdSql.error("select diff(col13) from test")
         tdSql.error("select diff(col14) from test")
 
+        tdSql.query("select ts,diff(col1),ts from test1")
+        tdSql.checkRows(10)
+        tdSql.checkData(0, 0, "2018-09-17 09:00:00.000")
+        tdSql.checkData(0, 1, "2018-09-17 09:00:00.000")
+        tdSql.checkData(0, 3, "2018-09-17 09:00:00.000")
+        tdSql.checkData(9, 0, "2018-09-17 09:00:00.009")
+        tdSql.checkData(9, 1, "2018-09-17 09:00:00.009")
+        tdSql.checkData(9, 3, "2018-09-17 09:00:00.009")
+
+        tdSql.query("select ts,diff(col1),ts from test group by tbname")
+        tdSql.checkRows(10)
+        tdSql.checkData(0, 0, "2018-09-17 09:00:00.000")
+        tdSql.checkData(0, 1, "2018-09-17 09:00:00.000")
+        tdSql.checkData(0, 3, "2018-09-17 09:00:00.000")
+        tdSql.checkData(9, 0, "2018-09-17 09:00:00.009")
+        tdSql.checkData(9, 1, "2018-09-17 09:00:00.009")
+        tdSql.checkData(9, 3, "2018-09-17 09:00:00.009")
 
         tdSql.query("select ts,diff(col1),ts from test1")
         tdSql.checkRows(10)
diff --git a/tests/pytest/functions/queryTestCases.py b/tests/pytest/functions/queryTestCases.py
index a2218b33ac..1311ad6b3c 100644
--- a/tests/pytest/functions/queryTestCases.py
+++ b/tests/pytest/functions/queryTestCases.py
@@ -884,6 +884,126 @@ class TDTestCase:
 
         pass
 
+    def td6068(self):
+        tdLog.printNoPrefix("==========TD-6068==========")
+        tdSql.execute("drop database if exists db")
+        tdSql.execute("create database  if not exists db keep 3650")
+        tdSql.execute("use db")
+
+        tdSql.execute("create stable db.stb1 (ts timestamp, c1 int, c2 float, c3 timestamp, c4 binary(16), c5 double, c6 bool) tags(t1 int)")
+
+        for i in range(100):
+            sql  = f"create table db.t{i} using db.stb1 tags({i})"
+            tdSql.execute(sql)
+            tdSql.execute(f"insert into db.t{i} values (now-10h, {i}, {i+random.random()}, now-10h, 'a_{i}', '{i-random.random()}', True)")
+            tdSql.execute(f"insert into db.t{i} values (now-9h, {i+random.randint(1,10)}, {i+random.random()}, now-9h, 'a_{i}', '{i-random.random()}', FALSE )")
+            tdSql.execute(f"insert into db.t{i} values (now-8h, {i+random.randint(1,10)}, {i+random.random()}, now-8h, 'b_{i}', '{i-random.random()}', True)")
+            tdSql.execute(f"insert into db.t{i} values (now-7h, {i+random.randint(1,10)}, {i+random.random()}, now-7h, 'b_{i}', '{i-random.random()}', FALSE )")
+            tdSql.execute(f"insert into db.t{i} values (now-6h, {i+random.randint(1,10)}, {i+random.random()}, now-6h, 'c_{i}', '{i-random.random()}', True)")
+            tdSql.execute(f"insert into db.t{i} values (now-5h, {i+random.randint(1,10)}, {i+random.random()}, now-5h, 'c_{i}', '{i-random.random()}', FALSE )")
+            tdSql.execute(f"insert into db.t{i} (ts)values (now-4h)")
+            tdSql.execute(f"insert into db.t{i} (ts)values (now-11h)")
+            tdSql.execute(f"insert into db.t{i} (ts)values (now-450m)")
+
+        tdSql.query("select ts as t,derivative(c1, 10m, 0) from t1")
+        tdSql.checkRows(5)
+        tdSql.checkCols(3)
+        for i in range(5):
+            data=tdSql.getData(i, 0)
+            tdSql.checkData(i, 1, data)
+        tdSql.query("select ts as t, derivative(c1, 1h, 0) from stb1 group by tbname")
+        tdSql.checkRows(500)
+        tdSql.checkCols(4)
+        tdSql.query("select ts as t, derivative(c1, 1s, 0) from t1")
+        tdSql.query("select ts as t, derivative(c1, 1d, 0) from t1")
+        tdSql.error("select ts as t, derivative(c1, 1h, 0) from stb1")
+        tdSql.query("select ts as t, derivative(c2, 1h, 0) from t1")
+        tdSql.checkRows(5)
+        tdSql.error("select ts as t, derivative(c3, 1h, 0) from t1")
+        tdSql.error("select ts as t, derivative(c4, 1h, 0) from t1")
+        tdSql.query("select ts as t, derivative(c5, 1h, 0) from t1")
+        tdSql.checkRows(5)
+        tdSql.error("select ts as t, derivative(c6, 1h, 0) from t1")
+        tdSql.error("select ts as t, derivative(t1, 1h, 0) from t1")
+
+        tdSql.query("select ts as t, diff(c1) from t1")
+        tdSql.checkRows(5)
+        tdSql.checkCols(3)
+        for i in range(5):
+            data=tdSql.getData(i, 0)
+            tdSql.checkData(i, 1, data)
+        tdSql.query("select ts as t, diff(c1) from stb1 group by tbname")
+        tdSql.checkRows(500)
+        tdSql.checkCols(4)
+        tdSql.query("select ts as t, diff(c1) from t1")
+        tdSql.query("select ts as t, diff(c1) from t1")
+        tdSql.error("select ts as t, diff(c1) from stb1")
+        tdSql.query("select ts as t, diff(c2) from t1")
+        tdSql.checkRows(5)
+        tdSql.error("select ts as t, diff(c3) from t1")
+        tdSql.error("select ts as t, diff(c4) from t1")
+        tdSql.query("select ts as t, diff(c5) from t1")
+        tdSql.checkRows(5)
+        tdSql.error("select ts as t, diff(c6) from t1")
+        tdSql.error("select ts as t, diff(t1) from t1")
+        tdSql.error("select ts as t, diff(c1, c2) from t1")
+
+        tdSql.error("select ts as t, bottom(c1, 0) from t1")
+        tdSql.query("select ts as t, bottom(c1, 5) from t1")
+        tdSql.checkRows(5)
+        tdSql.checkCols(3)
+        for i in range(5):
+            data=tdSql.getData(i, 0)
+            tdSql.checkData(i, 1, data)
+        tdSql.query("select ts as t, bottom(c1, 5) from stb1")
+        tdSql.checkRows(5)
+        tdSql.query("select ts as t, bottom(c1, 5) from stb1 group by tbname")
+        tdSql.checkRows(500)
+        tdSql.query("select ts as t, bottom(c1, 8) from t1")
+        tdSql.checkRows(6)
+        tdSql.query("select ts as t, bottom(c2, 8) from t1")
+        tdSql.checkRows(6)
+        tdSql.error("select ts as t, bottom(c3, 5) from t1")
+        tdSql.error("select ts as t, bottom(c4, 5) from t1")
+        tdSql.query("select ts as t, bottom(c5, 8) from t1")
+        tdSql.checkRows(6)
+        tdSql.error("select ts as t, bottom(c6, 5) from t1")
+        tdSql.error("select ts as t, bottom(c5, 8) as b from t1 order by b")
+        tdSql.error("select ts as t, bottom(t1, 1) from t1")
+        tdSql.error("select ts as t, bottom(t1, 1) from stb1")
+        tdSql.error("select ts as t, bottom(t1, 3) from stb1 order by c3")
+        tdSql.error("select ts as t, bottom(t1, 3) from t1 order by c3")
+
+
+        tdSql.error("select ts as t, top(c1, 0) from t1")
+        tdSql.query("select ts as t, top(c1, 5) from t1")
+        tdSql.checkRows(5)
+        tdSql.checkCols(3)
+        for i in range(5):
+            data=tdSql.getData(i, 0)
+            tdSql.checkData(i, 1, data)
+        tdSql.query("select ts as t, top(c1, 5) from stb1")
+        tdSql.checkRows(5)
+        tdSql.query("select ts as t, top(c1, 5) from stb1 group by tbname")
+        tdSql.checkRows(500)
+        tdSql.query("select ts as t, top(c1, 8) from t1")
+        tdSql.checkRows(6)
+        tdSql.query("select ts as t, top(c2, 8) from t1")
+        tdSql.checkRows(6)
+        tdSql.error("select ts as t, top(c3, 5) from t1")
+        tdSql.error("select ts as t, top(c4, 5) from t1")
+        tdSql.query("select ts as t, top(c5, 8) from t1")
+        tdSql.checkRows(6)
+        tdSql.error("select ts as t, top(c6, 5) from t1")
+        tdSql.error("select ts as t, top(c5, 8) as b from t1 order by b")
+        tdSql.error("select ts as t, top(t1, 1) from t1")
+        tdSql.error("select ts as t, top(t1, 1) from stb1")
+        tdSql.error("select ts as t, top(t1, 3) from stb1 order by c3")
+        tdSql.error("select ts as t, top(t1, 3) from t1 order by c3")
+
+        pass
+
+
     def run(self):
 
         # master branch
@@ -891,8 +1011,9 @@ class TDTestCase:
         # self.td4082()
         # self.td4288()
         # self.td4724()
-        self.td5798()
+        # self.td5798()
         # self.td5935()
+        self.td6068()
 
         # develop branch
         # self.td4097()
diff --git a/tests/script/api/makefile b/tests/script/api/makefile
index 7595594cbf..92d0a89b0f 100644
--- a/tests/script/api/makefile
+++ b/tests/script/api/makefile
@@ -6,7 +6,8 @@ TARGET=exe
 LFLAGS = '-Wl,-rpath,/usr/local/taos/driver/' -ltaos -lpthread -lm -lrt
 CFLAGS = -O0 -g -Wall -Wno-deprecated -fPIC -Wno-unused-result -Wconversion \
 	-Wno-char-subscripts -D_REENTRANT -Wno-format -D_REENTRANT -DLINUX \
-	-Wno-unused-function -D_M_X64 -I/usr/local/taos/include -std=gnu99
+	-Wno-unused-function -D_M_X64 -I/usr/local/taos/include -std=gnu99 \
+	-fsanitize=address
 
 all: $(TARGET)
 
@@ -14,8 +15,10 @@ exe:
 	gcc $(CFLAGS) ./batchprepare.c  -o $(ROOT)batchprepare  $(LFLAGS)
 	gcc $(CFLAGS) ./stmtBatchTest.c -o $(ROOT)stmtBatchTest $(LFLAGS)
 	gcc $(CFLAGS) ./stmtTest.c -o $(ROOT)stmtTest $(LFLAGS)
+	gcc $(CFLAGS) ./stmt_function.c -o $(ROOT)stmt_function $(LFLAGS)
 
 clean:
 	rm $(ROOT)batchprepare
 	rm $(ROOT)stmtBatchTest
 	rm $(ROOT)stmtTest
+	rm $(ROOT)stmt_function
diff --git a/tests/script/api/stmt_function.c b/tests/script/api/stmt_function.c
new file mode 100644
index 0000000000..64573ec994
--- /dev/null
+++ b/tests/script/api/stmt_function.c
@@ -0,0 +1,502 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "taos.h"
+#include <sys/time.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <assert.h>
+
+void execute_simple_sql(void *taos, char *sql) {
+    TAOS_RES *result = taos_query(taos, sql);
+    if ( result == NULL || taos_errno(result) != 0) {
+        printf( "failed to %s, Reason: %s\n" , sql, taos_errstr(result));
+        taos_free_result(result);
+        exit(EXIT_FAILURE);
+    }
+    taos_free_result(result);
+}
+
+void print_result(TAOS_RES* res) {
+    if (res == NULL) {
+        exit(EXIT_FAILURE);
+    }
+    TAOS_ROW    row = NULL;
+    int         num_fields = taos_num_fields(res);
+    TAOS_FIELD* fields = taos_fetch_fields(res);
+    while ((row = taos_fetch_row(res))) {
+        char temp[256] = {0};
+        taos_print_row(temp, row, fields, num_fields);
+        printf("get result: %s\n", temp);
+    }
+}
+
+void taos_stmt_init_test() {
+	printf("start taos_stmt_init test \n");
+    void *taos = NULL;
+	TAOS_STMT *stmt = NULL;
+    stmt = taos_stmt_init(taos);
+	assert(stmt == NULL);
+    // ASM ERROR
+	// assert(taos_stmt_close(stmt) != 0);
+	taos = taos_connect("127.0.0.1","root","taosdata",NULL,0);
+	if(taos == NULL) {
+		printf("Cannot connect to tdengine server\n");
+		exit(EXIT_FAILURE);
+	}
+	stmt = taos_stmt_init(taos);
+	assert(stmt != NULL);
+	assert(taos_stmt_close(stmt) == 0);
+    printf("finish taos_stmt_init test\n"); 
+}
+void taos_stmt_preprare_test() {
+    printf("start taos_stmt_prepare test\n");
+    char *stmt_sql = calloc(1, 1048576);
+    TAOS_STMT *stmt = NULL;
+    assert(taos_stmt_prepare(stmt, stmt_sql, 0) != 0);
+    void *taos = NULL;	
+	taos = taos_connect("127.0.0.1","root","taosdata",NULL,0);
+	if(taos == NULL) {
+		printf("Cannot connect to tdengine server\n");
+		exit(EXIT_FAILURE);
+	}
+    execute_simple_sql(taos, "drop database if exists stmt_test");
+    execute_simple_sql(taos, "create database stmt_test");
+    execute_simple_sql(taos, "use stmt_test");
+    execute_simple_sql(taos, "create table super(ts timestamp, c1 int, c2 bigint, c3 float, c4 double, c5 binary(8), c6 smallint, c7 tinyint, c8 bool, c9 nchar(8), c10 timestamp) tags (t1 int, t2 bigint, t3 float, t4 double, t5 binary(8), t6 smallint, t7 tinyint, t8 bool, t9 nchar(8))");
+    stmt = taos_stmt_init(taos);
+    assert(stmt != NULL);
+    // below will make client dead lock
+    assert(taos_stmt_prepare(stmt, stmt_sql, 0) == 0);
+
+    // assert(taos_stmt_close(stmt) == 0);
+    // stmt = taos_stmt_init(taos);
+    assert(stmt != NULL);
+    sprintf(stmt_sql, "select from ?");
+    assert(taos_stmt_prepare(stmt, stmt_sql, 0) != 0);
+    assert(taos_stmt_close(stmt) == 0);
+
+    stmt = taos_stmt_init(taos);
+    assert(stmt != NULL);
+    sprintf(stmt_sql, "insert into ? values (?,?,?,?,?,?,?,?,?,?,?)");
+    assert(taos_stmt_prepare(stmt, stmt_sql, 0) == 0);
+    assert(taos_stmt_close(stmt) == 0);
+
+    stmt = taos_stmt_init(taos);
+    assert(stmt != NULL);
+    sprintf(stmt_sql, "insert into super values (?,?,?,?,?,?,?,?,?,?,?)");
+    assert(taos_stmt_prepare(stmt, stmt_sql, 0) != 0);
+    assert(taos_stmt_close(stmt) == 0);
+
+    stmt = taos_stmt_init(taos);
+    assert(stmt != NULL);
+    sprintf(stmt_sql, "insert into ? values (?,?,?,?,?,?,?,?,1,?,?,?)");
+    assert(taos_stmt_prepare(stmt, stmt_sql, 0) == 0);
+    assert(taos_stmt_close(stmt) == 0);
+
+    free(stmt_sql);
+    printf("finish taos_stmt_prepare test\n");
+}
+
+void taos_stmt_set_tbname_test() {
+    printf("start taos_stmt_set_tbname test\n");
+    TAOS_STMT *stmt = NULL;
+    char *name = calloc(1, 200);
+    // ASM ERROR
+    // assert(taos_stmt_set_tbname(stmt, name) != 0);
+    void *taos = taos_connect("127.0.0.1","root","taosdata",NULL,0);
+	if(taos == NULL) {
+		printf("Cannot connect to tdengine server\n");
+		exit(EXIT_FAILURE);
+	}
+    execute_simple_sql(taos, "drop database if exists stmt_test");
+    execute_simple_sql(taos, "create database stmt_test");
+    execute_simple_sql(taos, "use stmt_test");
+    execute_simple_sql(taos, "create table super(ts timestamp, c1 int)");
+    stmt = taos_stmt_init(taos);
+    assert(stmt != NULL);
+    assert(taos_stmt_set_tbname(stmt, name) != 0);
+    char* stmt_sql = calloc(1, 1000);
+    sprintf(stmt_sql, "insert into ? values (?,?)");
+    assert(taos_stmt_prepare(stmt, stmt_sql, 0) == 0);
+    sprintf(name, "super");
+    assert(stmt != NULL);
+    assert(taos_stmt_set_tbname(stmt, name) == 0);
+    free(name);
+    free(stmt_sql);
+    taos_stmt_close(stmt);
+    printf("finish taos_stmt_set_tbname test\n");
+}
+
+void taos_stmt_set_tbname_tags_test() {
+    printf("start taos_stmt_set_tbname_tags test\n");
+    TAOS_STMT *stmt = NULL;
+    char *name = calloc(1,20);
+    TAOS_BIND *tags = calloc(1, sizeof(TAOS_BIND));
+    // ASM ERROR
+    // assert(taos_stmt_set_tbname_tags(stmt, name, tags) != 0);
+    void *taos = taos_connect("127.0.0.1","root","taosdata",NULL,0);
+	if(taos == NULL) {
+		printf("Cannot connect to tdengine server\n");
+		exit(EXIT_FAILURE);
+	}
+    execute_simple_sql(taos, "drop database if exists stmt_test");
+    execute_simple_sql(taos, "create database stmt_test");
+    execute_simple_sql(taos, "use stmt_test");
+    execute_simple_sql(taos, "create stable super(ts timestamp, c1 int) tags (id int)");
+    execute_simple_sql(taos, "create table tb using super tags (1)");
+    stmt = taos_stmt_init(taos);
+    assert(stmt != NULL);
+    char* stmt_sql = calloc(1, 1000);
+    sprintf(stmt_sql, "insert into ? using super tags (?) values (?,?)");
+    assert(taos_stmt_prepare(stmt, stmt_sql, 0) == 0);
+    assert(taos_stmt_set_tbname_tags(stmt, name, tags) != 0);
+    sprintf(name, "tb");
+    assert(taos_stmt_set_tbname_tags(stmt, name, tags) != 0);
+    int t = 1;
+    tags->buffer_length = TSDB_DATA_TYPE_INT;
+    tags->buffer_length = sizeof(uint32_t);
+    tags->buffer = &t;
+    tags->length = &tags->buffer_length;
+    tags->is_null = NULL;
+    assert(taos_stmt_set_tbname_tags(stmt, name, tags) == 0);
+    free(stmt_sql);
+    free(name);
+    free(tags);
+    taos_stmt_close(stmt);
+    printf("finish taos_stmt_set_tbname_tags test\n");
+}
+
+void taos_stmt_set_sub_tbname_test() {
+    printf("start taos_stmt_set_sub_tbname test\n");
+    TAOS_STMT *stmt = NULL;
+    char *name = calloc(1, 200);
+    // ASM ERROR
+    // assert(taos_stmt_set_sub_tbname(stmt, name) != 0);
+    void *taos = taos_connect("127.0.0.1","root","taosdata",NULL,0);
+	if(taos == NULL) {
+		printf("Cannot connect to tdengine server\n");
+		exit(EXIT_FAILURE);
+	}
+    execute_simple_sql(taos, "drop database if exists stmt_test");
+    execute_simple_sql(taos, "create database stmt_test");
+    execute_simple_sql(taos, "use stmt_test");
+    execute_simple_sql(taos, "create stable super(ts timestamp, c1 int) tags (id int)");
+    execute_simple_sql(taos, "create table tb using super tags (1)");
+    stmt = taos_stmt_init(taos);
+    assert(stmt != NULL);
+    char* stmt_sql = calloc(1, 1000);
+    sprintf(stmt_sql, "insert into ? values (?,?)");
+    assert(taos_stmt_prepare(stmt, stmt_sql, 0) == 0);
+    assert(taos_stmt_set_sub_tbname(stmt, name) != 0);
+    sprintf(name, "tb");
+    assert(taos_stmt_set_sub_tbname(stmt, name) == 0);
+    // assert(taos_load_table_info(taos, "super, tb") == 0);
+    // assert(taos_stmt_set_sub_tbname(stmt, name) == 0);
+    free(name);
+    free(stmt_sql);
+    assert(taos_stmt_close(stmt) == 0);
+    printf("finish taos_stmt_set_sub_tbname test\n");
+}
+
+void taos_stmt_bind_param_test() {
+    printf("start taos_stmt_bind_param test\n");
+    TAOS_STMT *stmt = NULL;
+    TAOS_BIND *binds = NULL;
+    assert(taos_stmt_bind_param(stmt, binds) != 0);
+    void *taos = taos_connect("127.0.0.1","root","taosdata",NULL,0);
+	if(taos == NULL) {
+		printf("Cannot connect to tdengine server\n");
+		exit(EXIT_FAILURE);
+	}
+    execute_simple_sql(taos, "drop database if exists stmt_test");
+    execute_simple_sql(taos, "create database stmt_test");
+    execute_simple_sql(taos, "use stmt_test");
+    execute_simple_sql(taos, "create table super(ts timestamp, c1 int)");
+    stmt = taos_stmt_init(taos);
+    char* stmt_sql = calloc(1, 1000);
+    sprintf(stmt_sql, "insert into ? values (?,?)");
+    assert(taos_stmt_prepare(stmt, stmt_sql, 0) == 0);
+    assert(taos_stmt_bind_param(stmt, binds) != 0);
+    free(binds);
+    TAOS_BIND *params = calloc(2, sizeof(TAOS_BIND));
+    int64_t ts = (int64_t)1591060628000;
+    params[0].buffer_type = TSDB_DATA_TYPE_TIMESTAMP;
+    params[0].buffer_length = sizeof(uint64_t);
+    params[0].buffer = &ts;
+    params[0].length = &params[0].buffer_length;
+    params[0].is_null = NULL;
+    int32_t i = (int32_t)21474;
+    params[1].buffer_type = TSDB_DATA_TYPE_INT;
+    params[1].buffer_length = sizeof(int32_t);
+    params[1].buffer = &i;
+    params[1].length = &params[1].buffer_length;
+    params[1].is_null = NULL;
+    assert(taos_stmt_bind_param(stmt, params) != 0);
+    assert(taos_stmt_set_tbname(stmt, "super") == 0);
+    assert(taos_stmt_bind_param(stmt, params) == 0);
+    free(params);
+    free(stmt_sql);
+    taos_stmt_close(stmt);
+    printf("finish taos_stmt_bind_param test\n");
+}
+
+void taos_stmt_bind_single_param_batch_test() {
+    printf("start taos_stmt_bind_single_param_batch test\n");
+    TAOS_STMT *stmt = NULL;
+    TAOS_MULTI_BIND *bind = NULL;
+    assert(taos_stmt_bind_single_param_batch(stmt, bind, 0) != 0);
+    printf("finish taos_stmt_bind_single_param_batch test\n");
+}
+
+void taos_stmt_bind_param_batch_test() {
+    printf("start taos_stmt_bind_param_batch test\n");
+    TAOS_STMT *stmt = NULL;
+    TAOS_MULTI_BIND *bind = NULL;
+    assert(taos_stmt_bind_param_batch(stmt, bind) != 0);
+    printf("finish taos_stmt_bind_param_batch test\n");
+}
+
+void taos_stmt_add_batch_test() {
+    printf("start taos_stmt_add_batch test\n");
+    TAOS_STMT *stmt = NULL;
+    assert(taos_stmt_add_batch(stmt) != 0);
+    void *taos = taos_connect("127.0.0.1","root","taosdata",NULL,0);
+	if(taos == NULL) {
+		printf("Cannot connect to tdengine server\n");
+		exit(EXIT_FAILURE);
+	}
+    execute_simple_sql(taos, "drop database if exists stmt_test");
+    execute_simple_sql(taos, "create database stmt_test");
+    execute_simple_sql(taos, "use stmt_test");
+    execute_simple_sql(taos, "create table super(ts timestamp, c1 int)");
+    stmt = taos_stmt_init(taos);
+    assert(stmt != NULL);
+    char* stmt_sql = calloc(1, 1000);
+    sprintf(stmt_sql, "insert into ? values (?,?)");
+    assert(taos_stmt_prepare(stmt, stmt_sql, 0) == 0);
+    assert(taos_stmt_add_batch(stmt) != 0);
+    TAOS_BIND *params = calloc(2, sizeof(TAOS_BIND));
+    int64_t ts = (int64_t)1591060628000;
+    params[0].buffer_type = TSDB_DATA_TYPE_TIMESTAMP;
+    params[0].buffer_length = sizeof(uint64_t);
+    params[0].buffer = &ts;
+    params[0].length = &params[0].buffer_length;
+    params[0].is_null = NULL;
+    int32_t i = (int32_t)21474;
+    params[1].buffer_type = TSDB_DATA_TYPE_INT;
+    params[1].buffer_length = sizeof(int32_t);
+    params[1].buffer = &i;
+    params[1].length = &params[1].buffer_length;
+    params[1].is_null = NULL;
+    assert(taos_stmt_set_tbname(stmt, "super") == 0);
+    assert(taos_stmt_bind_param(stmt, params) == 0);
+    assert(taos_stmt_add_batch(stmt) == 0);
+    free(params);
+    free(stmt_sql);
+    assert(taos_stmt_close(stmt) == 0);
+    printf("finish taos_stmt_add_batch test\n");
+}
+
+void taos_stmt_execute_test() {
+    printf("start taos_stmt_execute test\n");
+    TAOS_STMT *stmt = NULL;
+    assert(taos_stmt_execute(stmt) != 0);
+    void *taos = taos_connect("127.0.0.1","root","taosdata",NULL,0);
+	if(taos == NULL) {
+		printf("Cannot connect to tdengine server\n");
+		exit(EXIT_FAILURE);
+	}
+    execute_simple_sql(taos, "drop database if exists stmt_test");
+    execute_simple_sql(taos, "create database stmt_test");
+    execute_simple_sql(taos, "use stmt_test");
+    execute_simple_sql(taos, "create table super(ts timestamp, c1 int)");
+    stmt = taos_stmt_init(taos);
+    assert(stmt != NULL);
+    assert(taos_stmt_execute(stmt) != 0);
+    char* stmt_sql = calloc(1, 1000);
+    sprintf(stmt_sql, "insert into ? values (?,?)");
+    assert(taos_stmt_prepare(stmt, stmt_sql, 0) == 0);
+    assert(taos_stmt_execute(stmt) != 0);
+    TAOS_BIND *params = calloc(2, sizeof(TAOS_BIND));
+    int64_t ts = (int64_t)1591060628000;
+    params[0].buffer_type = TSDB_DATA_TYPE_TIMESTAMP;
+    params[0].buffer_length = sizeof(uint64_t);
+    params[0].buffer = &ts;
+    params[0].length = &params[0].buffer_length;
+    params[0].is_null = NULL;
+    int32_t i = (int32_t)21474;
+    params[1].buffer_type = TSDB_DATA_TYPE_INT;
+    params[1].buffer_length = sizeof(int32_t);
+    params[1].buffer = &i;
+    params[1].length = &params[1].buffer_length;
+    params[1].is_null = NULL;
+    assert(taos_stmt_set_tbname(stmt, "super") == 0);
+    assert(taos_stmt_execute(stmt) != 0);
+    assert(taos_stmt_bind_param(stmt, params) == 0);
+    assert(taos_stmt_execute(stmt) != 0);
+    assert(taos_stmt_add_batch(stmt) == 0);
+    assert(taos_stmt_execute(stmt) == 0);
+    free(params);
+    free(stmt_sql);
+    assert(taos_stmt_close(stmt) == 0);
+    printf("finish taos_stmt_execute test\n");
+}
+
+void taos_stmt_use_result_query(void *taos, char *col, int type) {
+    TAOS_STMT *stmt = taos_stmt_init(taos);
+    assert(stmt != NULL);
+    char *stmt_sql = calloc(1, 1024);
+    struct {
+        int64_t c1;
+        int32_t c2;
+        int64_t c3;
+        float c4;
+        double c5;
+        char c6[8];
+        int16_t c7;
+        int8_t c8;
+        int8_t c9;
+        char c10[32];
+    } v = {0};
+    v.c1 = (int64_t)1591060628000;
+    v.c2 = (int32_t)1;
+    v.c3 = (int64_t)1;
+    v.c4 = (float)1;
+    v.c5 = (double)1;
+    strcpy(v.c6, "abcdefgh");
+    v.c7 = 1;
+    v.c8 = 1;
+    v.c9 = 1;
+    strcpy(v.c10, "一二三四五六七八");
+    uintptr_t c10len=strlen(v.c10);
+    sprintf(stmt_sql, "select * from stmt_test.t1 where %s = ?", col);
+    printf("stmt_sql: %s\n", stmt_sql);
+    assert(taos_stmt_prepare(stmt, stmt_sql, 0) == 0);
+    TAOS_BIND *params = calloc(1, sizeof(TAOS_BIND));
+    params->buffer_type = type;
+    params->is_null = NULL;
+    switch(type){
+        case TSDB_DATA_TYPE_TIMESTAMP:
+            params->buffer_length = sizeof(v.c1);
+            params->buffer = &v.c1;
+            params->length = &params->buffer_length;
+            break;
+        case TSDB_DATA_TYPE_INT:
+            params->buffer_length = sizeof(v.c2);
+            params->buffer = &v.c2;
+            params->length = &params->buffer_length;
+        case TSDB_DATA_TYPE_BIGINT:
+            params->buffer_length = sizeof(v.c3);
+            params->buffer = &v.c3;
+            params->length = &params->buffer_length;
+            break;
+        case TSDB_DATA_TYPE_FLOAT:
+            params->buffer_length = sizeof(v.c4);
+            params->buffer = &v.c4;
+            params->length = &params->buffer_length;
+        case TSDB_DATA_TYPE_DOUBLE:
+            params->buffer_length = sizeof(v.c5);
+            params->buffer = &v.c5;
+            params->length = &params->buffer_length;
+            break;
+        case TSDB_DATA_TYPE_BINARY:
+            params->buffer_length = sizeof(v.c6);
+            params->buffer = &v.c6;
+            params->length = &params->buffer_length;
+            break;
+        case TSDB_DATA_TYPE_SMALLINT:
+            params->buffer_length = sizeof(v.c7);
+            params->buffer = &v.c7;
+            params->length = &params->buffer_length;
+            break;
+        case TSDB_DATA_TYPE_TINYINT:
+            params->buffer_length = sizeof(v.c8);
+            params->buffer = &v.c8;
+            params->length = &params->buffer_length;
+        case TSDB_DATA_TYPE_BOOL:
+            params->buffer_length = sizeof(v.c9);
+            params->buffer = &v.c9;
+            params->length = &params->buffer_length;
+            break;
+        case TSDB_DATA_TYPE_NCHAR:
+            params->buffer_length = sizeof(v.c10);
+            params->buffer = &v.c10;
+            params->length = &c10len;
+            break;
+        default:
+            printf("Cannnot find type: %d\n", type);
+            break;
+
+    }
+    assert(taos_stmt_bind_param(stmt, params) == 0);
+    assert(taos_stmt_execute(stmt) == 0);
+    TAOS_RES* result = taos_stmt_use_result(stmt);
+    assert(result != NULL);
+    print_result(result);
+    assert(taos_stmt_close(stmt) == 0);
+    free(params);
+    free(stmt_sql);
+    taos_free_result(result);
+}
+
+void taos_stmt_use_result_test() {
+    printf("start taos_stmt_use_result test\n");
+    void *taos = taos_connect("127.0.0.1","root","taosdata",NULL,0);
+    if(taos == NULL) {
+		printf("Cannot connect to tdengine server\n");
+		exit(EXIT_FAILURE);
+	}
+    execute_simple_sql(taos, "drop database if exists stmt_test");
+    execute_simple_sql(taos, "create database stmt_test");
+    execute_simple_sql(taos, "use stmt_test");
+    execute_simple_sql(taos, "create table super(ts timestamp, c1 int, c2 bigint, c3 float, c4 double, c5 binary(8), c6 smallint, c7 tinyint, c8 bool, c9 nchar(8), c10 timestamp) tags (t1 int, t2 bigint, t3 float, t4 double, t5 binary(8), t6 smallint, t7 tinyint, t8 bool, t9 nchar(8))");
+    execute_simple_sql(taos, "create table t1 using super tags (1, 1, 1, 1, 'abcdefgh',1,1,1,'一二三四五六七八')");
+    execute_simple_sql(taos, "insert into t1 values (1591060628000, 1, 1, 1, 1, 'abcdefgh',1,1,1,'一二三四五六七八', now)");
+    execute_simple_sql(taos, "insert into t1 values (1591060628001, 1, 1, 1, 1, 'abcdefgh',1,1,1,'一二三四五六七八', now)");
+    
+    taos_stmt_use_result_query(taos, "c1", TSDB_DATA_TYPE_INT);
+    taos_stmt_use_result_query(taos, "c2", TSDB_DATA_TYPE_BIGINT);
+    taos_stmt_use_result_query(taos, "c3", TSDB_DATA_TYPE_FLOAT);
+    taos_stmt_use_result_query(taos, "c4", TSDB_DATA_TYPE_DOUBLE);
+    taos_stmt_use_result_query(taos, "c5", TSDB_DATA_TYPE_BINARY);
+    taos_stmt_use_result_query(taos, "c6", TSDB_DATA_TYPE_SMALLINT);
+    taos_stmt_use_result_query(taos, "c7", TSDB_DATA_TYPE_TINYINT);
+    taos_stmt_use_result_query(taos, "c8", TSDB_DATA_TYPE_BOOL);
+    taos_stmt_use_result_query(taos, "c9", TSDB_DATA_TYPE_NCHAR);
+    
+    printf("finish taos_stmt_use_result test\n");
+}
+
+void taos_stmt_close_test() {
+    printf("start taos_stmt_close test\n");
+    // ASM ERROR
+    // TAOS_STMT *stmt = NULL;
+    // assert(taos_stmt_close(stmt) != 0);
+    printf("finish taos_stmt_close test\n");
+}
+
+void test_api_reliability() {
+	// ASM catch memory leak
+    taos_stmt_init_test();
+	taos_stmt_preprare_test();
+    taos_stmt_set_tbname_test();
+    taos_stmt_set_tbname_tags_test();
+    taos_stmt_set_sub_tbname_test();
+    taos_stmt_bind_param_test();
+    taos_stmt_bind_single_param_batch_test();
+    taos_stmt_bind_param_batch_test();
+    taos_stmt_add_batch_test();
+    taos_stmt_execute_test();
+    taos_stmt_close_test();
+}
+
+void test_query() {
+    taos_stmt_use_result_test();
+}
+
+int main(int argc, char *argv[]) {
+    test_api_reliability();
+    test_query();
+    return 0;
+}
\ No newline at end of file