diff --git a/docs/en/12-taos-sql/10-function.md b/docs/en/12-taos-sql/10-function.md
index 6b62950ecc..081d5a8d8a 100644
--- a/docs/en/12-taos-sql/10-function.md
+++ b/docs/en/12-taos-sql/10-function.md
@@ -998,18 +998,14 @@ SAMPLE(expr, k)
 
 **Description**: _k_ sampling values of a specific column. The applicable range of _k_ is [1,1000].
 
-**Return value type**: Same as the column being operated plus the associated timestamp
+**Return value type**: Same as the column being operated
 
-**Applicable data types**: Any data type except for tags of STable
+**Applicable data types**: Any data type
 
 **Applicable nested query**: Inner query and Outer query
 
 **Applicable table types**: standard tables and supertables
 
-**More explanations**:
-
-- This function cannot be used in expression calculation.
-
 
 ### TAIL
 
@@ -1054,11 +1050,11 @@ TOP(expr, k)
 UNIQUE(expr)
 ```
 
-**Description**: The values that occur the first time in the specified column. The effect is similar to `distinct` keyword, but it can also be used to match tags or timestamp. The first occurrence of a timestamp or tag is used.
+**Description**: The values that occur the first time in the specified column. The effect is similar to `distinct` keyword.
 
 **Return value type**:Same as the data type of the column being operated upon
 
-**Applicable column types**: Any data types except for timestamp
+**Applicable column types**: Any data types
 
 **Applicable table types**: table, STable
 
diff --git a/docs/zh/12-taos-sql/10-function.md b/docs/zh/12-taos-sql/10-function.md
index b4785dc5e6..4820eb4674 100644
--- a/docs/zh/12-taos-sql/10-function.md
+++ b/docs/zh/12-taos-sql/10-function.md
@@ -990,18 +990,14 @@ SAMPLE(expr, k)
 
 **功能说明**： 获取数据的 k 个采样值。参数 k 的合法输入范围是 1≤ k ≤ 1000。
 
-**返回结果类型**： 同原始数据类型， 返回结果中带有该行记录的时间戳。
+**返回结果类型**： 同原始数据类型。
 
-**适用数据类型**： 在超级表查询中使用时，不能应用在标签之上。
+**适用数据类型**： 全部类型字段。
 
 **嵌套子查询支持**： 适用于内层查询和外层查询。
 
 **适用于**：表和超级表。
 
-**使用说明**：
-
-- 不能参与表达式计算；该函数可以应用在普通表和超级表上；
-
 
 ### TAIL
 
@@ -1046,11 +1042,11 @@ TOP(expr, k)
 UNIQUE(expr)
 ```
 
-**功能说明**：返回该列的数值首次出现的值。该函数功能与 distinct 相似，但是可以匹配标签和时间戳信息。可以针对除时间列以外的字段进行查询，可以匹配标签和时间戳，其中的标签和时间戳是第一次出现时刻的标签和时间戳。
+**功能说明**：返回该列数据首次出现的值。该函数功能与 distinct 相似。
 
 **返回数据类型**：同应用的字段。
 
-**适用数据类型**：适合于除时间类型以外的字段。
+**适用数据类型**：全部类型字段。
 
 **适用于**: 表和超级表。
 
diff --git a/include/libs/function/tudf.h b/include/libs/function/tudf.h
index b71d50d43c..6b15833917 100644
--- a/include/libs/function/tudf.h
+++ b/include/libs/function/tudf.h
@@ -111,6 +111,12 @@ int32_t udfStartUdfd(int32_t startDnodeId);
  */
 int32_t udfStopUdfd();
 
+/**
+ * get udfd pid
+ *
+ */
+ int32_t udfGetUdfdPid(int32_t* pUdfdPid);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/client/src/clientSml.c b/source/client/src/clientSml.c
index 503120fe85..13dc019feb 100644
--- a/source/client/src/clientSml.c
+++ b/source/client/src/clientSml.c
@@ -749,6 +749,9 @@ static int32_t smlSendMetaMsg(SSmlHandle *info, SName *pName, SArray *pColumns,
     pReq.suid = pTableMeta->uid;
     pReq.source = TD_REQ_FROM_TAOX;
     pSql = (action == SCHEMA_ACTION_ADD_COLUMN) ? "sml_add_column" : "sml_modify_column_size";
+  } else{
+    uError("SML:0x%" PRIx64 " invalid action:%d", info->id, action);
+    goto end;
   }
 
   code = buildRequest(info->taos->id, pSql, strlen(pSql), NULL, false, &pRequest, 0);
diff --git a/source/client/src/clientStmt.c b/source/client/src/clientStmt.c
index 975b304bf4..8ac9550aca 100644
--- a/source/client/src/clientStmt.c
+++ b/source/client/src/clientStmt.c
@@ -939,8 +939,6 @@ int stmtClose(TAOS_STMT* stmt) {
   stmtCleanSQLInfo(pStmt);
   taosMemoryFree(stmt);
 
-  STMT_DLOG_E("stmt freed");
-
   return TSDB_CODE_SUCCESS;
 }
 
diff --git a/source/client/src/clientTmq.c b/source/client/src/clientTmq.c
index e1b2b9c48b..765ff2e0ed 100644
--- a/source/client/src/clientTmq.c
+++ b/source/client/src/clientTmq.c
@@ -651,7 +651,7 @@ static void asyncCommitOffset(tmq_t* tmq, const TAOS_RES* pRes, int32_t type, tm
   int32_t j = 0;
   int32_t numOfVgroups = taosArrayGetSize(pTopic->vgs);
   for (j = 0; j < numOfVgroups; j++) {
-    SMqClientVg* pVg = taosArrayGet(pTopic->vgs, j);
+    SMqClientVg* pVg = (SMqClientVg*)taosArrayGet(pTopic->vgs, j);
     if (pVg->vgId == vgId) {
       break;
     }
@@ -665,7 +665,7 @@ static void asyncCommitOffset(tmq_t* tmq, const TAOS_RES* pRes, int32_t type, tm
     return;
   }
 
-  SMqClientVg* pVg = taosArrayGet(pTopic->vgs, j);
+  SMqClientVg* pVg = (SMqClientVg*)taosArrayGet(pTopic->vgs, j);
   if (pVg->offsetInfo.currentOffset.type > 0 && !tOffsetEqual(&pVg->offsetInfo.currentOffset, &pVg->offsetInfo.committedOffset)) {
     code = doSendCommitMsg(tmq, pVg, pTopic->topicName, pParamSet, j, numOfVgroups, type);
 
@@ -741,13 +741,15 @@ static void asyncCommitAllOffsets(tmq_t* tmq, tmq_commit_cb* pCommitFp, void* us
 
 static void generateTimedTask(int64_t refId, int32_t type) {
   tmq_t* tmq = taosAcquireRef(tmqMgmt.rsetId, refId);
-  if (tmq != NULL) {
-    int8_t* pTaskType = taosAllocateQitem(sizeof(int8_t), DEF_QITEM, 0);
-    *pTaskType = type;
-    taosWriteQitem(tmq->delayedTask, pTaskType);
-    tsem_post(&tmq->rspSem);
-    taosReleaseRef(tmqMgmt.rsetId, refId);
-  }
+  if(tmq == NULL) return;
+
+  int8_t* pTaskType = taosAllocateQitem(sizeof(int8_t), DEF_QITEM, 0);
+  if(pTaskType == NULL) return;
+
+  *pTaskType = type;
+  taosWriteQitem(tmq->delayedTask, pTaskType);
+  tsem_post(&tmq->rspSem);
+  taosReleaseRef(tmqMgmt.rsetId, refId);
 }
 
 void tmqAssignAskEpTask(void* param, void* tmrId) {
@@ -762,19 +764,19 @@ void tmqAssignDelayedCommitTask(void* param, void* tmrId) {
   taosMemoryFree(param);
 }
 
-void tmqAssignDelayedReportTask(void* param, void* tmrId) {
-  int64_t refId = *(int64_t*)param;
-  tmq_t*  tmq = taosAcquireRef(tmqMgmt.rsetId, refId);
-  if (tmq != NULL) {
-    int8_t* pTaskType = taosAllocateQitem(sizeof(int8_t), DEF_QITEM, 0);
-    *pTaskType = TMQ_DELAYED_TASK__REPORT;
-    taosWriteQitem(tmq->delayedTask, pTaskType);
-    tsem_post(&tmq->rspSem);
-  }
-
-  taosReleaseRef(tmqMgmt.rsetId, refId);
-  taosMemoryFree(param);
-}
+//void tmqAssignDelayedReportTask(void* param, void* tmrId) {
+//  int64_t refId = *(int64_t*)param;
+//  tmq_t*  tmq = taosAcquireRef(tmqMgmt.rsetId, refId);
+//  if (tmq != NULL) {
+//    int8_t* pTaskType = taosAllocateQitem(sizeof(int8_t), DEF_QITEM, 0);
+//    *pTaskType = TMQ_DELAYED_TASK__REPORT;
+//    taosWriteQitem(tmq->delayedTask, pTaskType);
+//    tsem_post(&tmq->rspSem);
+//  }
+//
+//  taosReleaseRef(tmqMgmt.rsetId, refId);
+//  taosMemoryFree(param);
+//}
 
 int32_t tmqHbCb(void* param, SDataBuf* pMsg, int32_t code) {
   if (pMsg) {
diff --git a/source/common/src/ttime.c b/source/common/src/ttime.c
index d8c43747f7..7a5581efbe 100644
--- a/source/common/src/ttime.c
+++ b/source/common/src/ttime.c
@@ -969,7 +969,7 @@ void taosFormatUtcTime(char* buf, int32_t bufLen, int64_t t, int32_t precision)
 
     default:
       fractionLen = 0;
-      ASSERT(false);
+      return;
   }
 
   if (taosLocalTime(&quot, &ptm, buf) == NULL) {
diff --git a/source/dnode/mnode/impl/src/mndProfile.c b/source/dnode/mnode/impl/src/mndProfile.c
index 0bfab227c4..ced52058e1 100644
--- a/source/dnode/mnode/impl/src/mndProfile.c
+++ b/source/dnode/mnode/impl/src/mndProfile.c
@@ -232,7 +232,6 @@ static int32_t mndProcessConnectReq(SRpcMsg *pReq) {
   }
 
   code = -1;
-
   taosIp2String(pReq->info.conn.clientIp, ip);
   if (mndCheckOperPrivilege(pMnode, pReq->info.conn.user, MND_OPER_CONNECT) != 0) {
     mGError("user:%s, failed to login from %s since %s", pReq->info.conn.user, ip, terrstr());
@@ -244,7 +243,7 @@ static int32_t mndProcessConnectReq(SRpcMsg *pReq) {
     mGError("user:%s, failed to login from %s while acquire user since %s", pReq->info.conn.user, ip, terrstr());
     goto _OVER;
   }
-
+  
   if (strncmp(connReq.passwd, pUser->pass, TSDB_PASSWORD_LEN - 1) != 0) {
     mGError("user:%s, failed to login from %s since invalid pass, input:%s", pReq->info.conn.user, ip, connReq.passwd);
     code = TSDB_CODE_MND_AUTH_FAILURE;
@@ -270,6 +269,7 @@ static int32_t mndProcessConnectReq(SRpcMsg *pReq) {
     }
   }
 
+_CONNECT:
   pConn = mndCreateConn(pMnode, pReq->info.conn.user, connReq.connType, pReq->info.conn.clientIp,
                         pReq->info.conn.clientPort, connReq.pid, connReq.app, connReq.startTime);
   if (pConn == NULL) {
diff --git a/source/libs/function/src/thistogram.c b/source/libs/function/src/thistogram.c
index e7d631f638..b56691f35d 100644
--- a/source/libs/function/src/thistogram.c
+++ b/source/libs/function/src/thistogram.c
@@ -474,8 +474,8 @@ double* tHistogramUniform(SHistogramInfo* pHisto, double* ratio, int32_t num) {
     }
 
     ASSERTS(total <= numOfElem && total + pHisto->elems[j + 1].num > numOfElem,
-            "tHistogramUniform Error, total:%d, numOfElem:%d, elems[%d].num:%d",
-            total, numOfElem, j + 1, pHisto->elems[j + 1].num);
+            "tHistogramUniform Error, total:%ld, numOfElem:%ld, elems[%d].num:%ld",
+            total, (int64_t)numOfElem, j + 1, pHisto->elems[j + 1].num);
 
     double delta = numOfElem - total;
     if (fabs(delta) < FLT_EPSILON) {
diff --git a/source/libs/function/src/tpercentile.c b/source/libs/function/src/tpercentile.c
index 3ec802a7ce..8101b342a4 100644
--- a/source/libs/function/src/tpercentile.c
+++ b/source/libs/function/src/tpercentile.c
@@ -39,6 +39,7 @@ static SFilePage *loadDataFromFilePage(tMemBucket *pMemBucket, int32_t slotIdx)
   if (p != NULL) {
     pIdList = *(SArray **)p;
   } else {
+    taosMemoryFree(buffer);
     return NULL;
   }
 
@@ -48,6 +49,7 @@ static SFilePage *loadDataFromFilePage(tMemBucket *pMemBucket, int32_t slotIdx)
 
     SFilePage *pg = getBufPage(pMemBucket->pBuffer, *pageId);
     if (pg == NULL) {
+      taosMemoryFree(buffer);
       return NULL;
     }
 
diff --git a/source/libs/function/src/tudf.c b/source/libs/function/src/tudf.c
index 31a7dfdbc5..5b9f44c812 100644
--- a/source/libs/function/src/tudf.c
+++ b/source/libs/function/src/tudf.c
@@ -255,6 +255,18 @@ int32_t udfStopUdfd() {
   return 0;
 }
 
+int32_t udfGetUdfdPid(int32_t* pUdfdPid) {
+  SUdfdData *pData = &udfdGlobal;
+  if (pData->spawnErr) {
+    return pData->spawnErr;
+  }
+  uv_pid_t pid = uv_process_get_pid(&pData->process);
+  if (pUdfdPid) {
+    *pUdfdPid = (int32_t)pid;
+  }
+  return TSDB_CODE_SUCCESS;
+}
+
 //==============================================================================================
 /* Copyright (c) 2013, Ben Noordhuis <info@bnoordhuis.nl>
  * The QUEUE is copied from queue.h under libuv
diff --git a/source/libs/function/src/udfd.c b/source/libs/function/src/udfd.c
index 3b827a2f99..93259924d5 100644
--- a/source/libs/function/src/udfd.c
+++ b/source/libs/function/src/udfd.c
@@ -965,40 +965,6 @@ int32_t udfdFillUdfInfoFromMNode(void *clientRpc, char *udfName, SUdf *udf) {
   return code;
 }
 
-int32_t udfdConnectToMnode() {
-  SConnectReq connReq = {0};
-  connReq.connType = CONN_TYPE__UDFD;
-  tstrncpy(connReq.app, "udfd", sizeof(connReq.app));
-  tstrncpy(connReq.user, TSDB_DEFAULT_USER, sizeof(connReq.user));
-  char pass[TSDB_PASSWORD_LEN + 1] = {0};
-  taosEncryptPass_c((uint8_t *)(TSDB_DEFAULT_PASS), strlen(TSDB_DEFAULT_PASS), pass);
-  tstrncpy(connReq.passwd, pass, sizeof(connReq.passwd));
-  connReq.pid = taosGetPId();
-  connReq.startTime = taosGetTimestampMs();
-  strcpy(connReq.sVer, version);
-
-  int32_t contLen = tSerializeSConnectReq(NULL, 0, &connReq);
-  void   *pReq = rpcMallocCont(contLen);
-  tSerializeSConnectReq(pReq, contLen, &connReq);
-
-  SUdfdRpcSendRecvInfo *msgInfo = taosMemoryCalloc(1, sizeof(SUdfdRpcSendRecvInfo));
-  msgInfo->rpcType = UDFD_RPC_MNODE_CONNECT;
-  uv_sem_init(&msgInfo->resultSem, 0);
-
-  SRpcMsg rpcMsg = {0};
-  rpcMsg.msgType = TDMT_MND_CONNECT;
-  rpcMsg.pCont = pReq;
-  rpcMsg.contLen = contLen;
-  rpcMsg.info.ahandle = msgInfo;
-  rpcSendRequest(global.clientRpc, &global.mgmtEp.epSet, &rpcMsg, NULL);
-
-  uv_sem_wait(&msgInfo->resultSem);
-  int32_t code = msgInfo->code;
-  uv_sem_destroy(&msgInfo->resultSem);
-  taosMemoryFree(msgInfo);
-  return code;
-}
-
 static bool udfdRpcRfp(int32_t code, tmsg_t msgType) {
   if (code == TSDB_CODE_RPC_NETWORK_UNAVAIL || code == TSDB_CODE_RPC_BROKEN_LINK || code == TSDB_CODE_SYN_NOT_LEADER ||
       code == TSDB_CODE_RPC_SOMENODE_NOT_CONNECTED || code == TSDB_CODE_SYN_RESTORING ||
@@ -1378,23 +1344,6 @@ static int32_t udfdRun() {
   return 0;
 }
 
-void udfdConnectMnodeThreadFunc(void *args) {
-  int32_t retryMnodeTimes = 0;
-  int32_t code = 0;
-  while (retryMnodeTimes++ <= TSDB_MAX_REPLICA) {
-    uv_sleep(100 * (1 << retryMnodeTimes));
-    code = udfdConnectToMnode();
-    if (code == 0) {
-      break;
-    }
-    fnError("udfd can not connect to mnode, code: %s. retry", tstrerror(code));
-  }
-
-  if (code != 0) {
-    fnError("udfd can not connect to mnode");
-  }
-}
-
 int32_t udfdInitResidentFuncs() {
   if (strlen(tsUdfdResFuncs) == 0) {
     return TSDB_CODE_SUCCESS;
@@ -1497,9 +1446,6 @@ int main(int argc, char *argv[]) {
 
   udfdInitResidentFuncs();
 
-  uv_thread_t mnodeConnectThread;
-  uv_thread_create(&mnodeConnectThread, udfdConnectMnodeThreadFunc, NULL);
-
   udfdRun();
 
   removeListeningPipe();
diff --git a/source/libs/scalar/src/filter.c b/source/libs/scalar/src/filter.c
index bbefcc6b3a..c0213c8861 100644
--- a/source/libs/scalar/src/filter.c
+++ b/source/libs/scalar/src/filter.c
@@ -3741,10 +3741,10 @@ int32_t fltSclBuildRangeFromBlockSma(SFltSclColumnRange *colRange, SColumnDataAg
     taosArrayPush(points, &startPt);
     taosArrayPush(points, &endPt);
   }
-  SFltSclDatum min;
+  SFltSclDatum min = {0};
   fltSclBuildDatumFromBlockSmaValue(&min, colRange->colNode->node.resType.type, pAgg->min);
   SFltSclPoint minPt = {.excl = false, .start = true, .val = min};
-  SFltSclDatum max;
+  SFltSclDatum max = {0};
   fltSclBuildDatumFromBlockSmaValue(&max, colRange->colNode->node.resType.type, pAgg->max);
   SFltSclPoint maxPt = {.excl = false, .start = false, .val = max};
   taosArrayPush(points, &minPt);
diff --git a/tests/script/tsim/query/udf.sim b/tests/script/tsim/query/udf.sim
index e539f11531..fbf9d50c25 100644
--- a/tests/script/tsim/query/udf.sim
+++ b/tests/script/tsim/query/udf.sim
@@ -8,6 +8,9 @@ system sh/deploy.sh -n dnode1 -i 1
 system sh/cfg.sh -n dnode1 -c udf -v 1
 system sh/exec.sh -n dnode1 -s start
 sql connect
+sql alter user root pass 'taosdata2'
+system sh/exec.sh -n dnode1 -s stop
+system sh/exec.sh -n dnode1 -s start
 
 print ======== step1 udf
 system sh/compile_udf.sh
diff --git a/tools/shell/src/shellWebsocket.c b/tools/shell/src/shellWebsocket.c
index d8920cb4c3..af7f13c69c 100644
--- a/tools/shell/src/shellWebsocket.c
+++ b/tools/shell/src/shellWebsocket.c
@@ -17,6 +17,9 @@
 #include <taosws.h>
 #include <shellInt.h>
 
+// save current database name
+char curDBName[128] = ""; // TDB_MAX_DBNAME_LEN is 24, put large
+
 int shell_conn_ws_server(bool first) {
   char cuttedDsn[SHELL_WS_DSN_BUFF] = {0};
   int dsnLen = strlen(shell.args.dsn);
@@ -59,6 +62,14 @@ int shell_conn_ws_server(bool first) {
     fprintf(stdout, "successfully connected to cloud service\n");
   }
   fflush(stdout);
+
+  // switch to current database if have
+  if(curDBName[0] !=0) {
+    char command[256];
+    sprintf(command, "use %s;", curDBName);
+    shellRunSingleCommandWebsocketImp(command);
+  }
+
   return 0;
 }
 
@@ -290,7 +301,46 @@ void shellRunSingleCommandWebsocketImp(char *command) {
 
   if (shellRegexMatch(command, "^\\s*use\\s+[a-zA-Z0-9_]+\\s*;\\s*$",
                       REG_EXTENDED | REG_ICASE)) {
-    fprintf(stdout, "Database changed.\r\n\r\n");
+
+    // copy dbname to curDBName
+    char *p         = command;
+    bool firstStart = false;
+    bool firstEnd   = false;
+    int  i          = 0;
+    while (*p != 0) {
+      if (*p != ' ') {
+        // not blank
+        if (!firstStart) {
+          firstStart = true;
+        } else if (firstEnd) {
+          if(*p == ';' && *p != '\\') {
+            break;
+          }
+          // database name
+          curDBName[i++] = *p;
+          if(i + 4 > sizeof(curDBName)) {
+            // DBName is too long, reset zero and break
+            i = 0;
+            break;
+          }
+        }
+      } else {
+        // blank
+        if(firstStart == true && firstEnd == false){
+          firstEnd = true;
+        }
+        if(firstStart && firstEnd && i > 0){
+          // blank after database name
+          break;
+        }
+      }
+      // move next
+      p++;
+    }
+    // append end
+    curDBName[i] = 0;
+
+    fprintf(stdout, "Database changed to %s.\r\n\r\n", curDBName);
     fflush(stdout);
     ws_free_result(res);
     return;