Merge pull request #3971 from taosdata/release/s104

Release/s104
2020-10-23 14:29:04 +08:00 · 2020-10-23 14:29:04 +08:00 · c42cfea1ab
parent d08caf9fa5 f830a04240
commit c42cfea1ab
229 changed files with 29147 additions and 2315 deletions
--- a/.travis.yml
+++ b/.travis.yml
@ -32,6 +32,8 @@ matrix:
          - python3-setuptools
          - valgrind
          - psmisc
+          - unixodbc
+          - unixodbc-dev

    before_script:
      - export TZ=Asia/Harbin
@ -54,6 +56,7 @@ matrix:

          py3ver=`python3 --version|awk '{print $2}'|cut -d "." -f 1,2` && apt install python$py3ver-dev
          pip3 install psutil
+          pip3 install guppy3
          pip3 install --user ${TRAVIS_BUILD_DIR}/src/connector/python/linux/python3/

          cd ${TRAVIS_BUILD_DIR}/tests
--- a/165
+++ b/165
@ -1,70 +1,143 @@
 pipeline {
-  agent any
-  stages {
-    stage('build TDengine') {
-      steps {
-        sh '''cd ${WORKSPACE}
-export TZ=Asia/Harbin
-date
-rm -rf ${WORKSPACE}/debug
-mkdir debug
-cd debug
-cmake .. > /dev/null
-make > /dev/null
-cd ${WORKSPACE}/debug'''
-      }
-    }
+  agent none
+  environment{
+      WK = '/var/lib/jenkins/workspace/TDinternal'
+      WKC= '/var/lib/jenkins/workspace/TDinternal/community'
+  }

-    stage('test_tsim') {
+  stages {
+      stage('Parallel test stage') {
      parallel {
-        stage('test') {
+        stage('pytest') {
+          agent{label 'master'}
          steps {
-            sh '''cd ${WORKSPACE}/tests
-#./test-all.sh smoke
-sudo ./test-all.sh full'''
+            sh '''
+            date
+            cd ${WKC}
+            git checkout develop
+            git pull
+            git submodule update
+            cd ${WK}
+            git checkout develop
+            git pull
+            export TZ=Asia/Harbin
+            date
+            rm -rf ${WK}/debug
+            mkdir debug
+            cd debug
+            cmake .. > /dev/null
+            make > /dev/null
+            cd ${WKC}/tests
+            #./test-all.sh smoke
+            ./test-all.sh pytest
+            date'''
+          }
+        }
+        stage('test_b1') {
+          agent{label '184'}
+          steps {
+            sh '''
+            cd ${WKC}
+            git checkout develop
+            git pull
+              
+            git submodule update
+            cd ${WK}
+            git checkout develop
+            git pull
+            export TZ=Asia/Harbin
+            date
+            rm -rf ${WK}/debug
+            mkdir debug
+            cd debug
+            cmake .. > /dev/null
+            make > /dev/null
+            cd ${WKC}/tests
+            #./test-all.sh smoke
+            ./test-all.sh b1
+            date'''
          }
        }

        stage('test_crash_gen') {
+          agent{label "185"}
          steps {
-            sh '''cd ${WORKSPACE}/tests/pytest
-sudo ./crash_gen.sh -a -p -t 4 -s 2000'''
+            sh '''
+            cd ${WKC}
+            git checkout develop
+            git pull
+              
+            git submodule update
+            cd ${WK}
+            git checkout develop
+            git pull
+            export TZ=Asia/Harbin
+            
+            rm -rf ${WK}/debug
+            mkdir debug
+            cd debug
+            cmake .. > /dev/null
+            make > /dev/null
+            cd ${WKC}/tests/pytest
+            ./crash_gen.sh -a -p -t 4 -s 2000
+            date
+            cd ${WKC}/tests
+            ./test-all.sh b2
+            date
+            '''
          }
        }

        stage('test_valgrind') {
+          agent{label "186"}
+
          steps {
-            sh '''cd ${WORKSPACE}/tests/pytest
-sudo ./valgrind-test.sh 2>&1 > mem-error-out.log
-grep \'start to execute\\|ERROR SUMMARY\' mem-error-out.log|grep -v \'grep\'|uniq|tee uniq-mem-error-out.log
+            sh '''
+            cd ${WKC}
+            git checkout develop
+            git pull
              
-for memError in `grep \'ERROR SUMMARY\' uniq-mem-error-out.log | awk \'{print $4}\'`
-do
-  if [ -n "$memError" ]; then
-    if [ "$memError" -gt 12 ]; then
-      echo -e "${RED} ## Memory errors number valgrind reports is $memError.\\
-               More than our threshold! ## ${NC}"
-      travis_terminate $memError
-    fi
-  fi
-done
+            git submodule update
+            cd ${WK}
+            git checkout develop
+            git pull
+            export TZ=Asia/Harbin
+            date
+            rm -rf ${WK}/debug
+            mkdir debug
+            cd debug
+            cmake .. > /dev/null
+            make > /dev/null
+            cd ${WKC}/tests/pytest
+            ./valgrind-test.sh 2>&1 > mem-error-out.log
+            ./handle_val_log.sh
          
-grep \'start to execute\\|definitely lost:\' mem-error-out.log|grep -v \'grep\'|uniq|tee uniq-definitely-lost-out.log
-for defiMemError in `grep \'definitely lost:\' uniq-definitely-lost-out.log | awk \'{print $7}\'`
-do
-  if [ -n "$defiMemError" ]; then
-    if [ "$defiMemError" -gt 13 ]; then
-      echo -e "${RED} ## Memory errors number valgrind reports \\
-               Definitely lost is $defiMemError. More than our threshold! ## ${NC}"
-      travis_terminate $defiMemError
-    fi
-  fi
-done'''
+            date
+            cd ${WKC}/tests
+            ./test-all.sh b3
+            date'''
          }
        }
+       stage('connector'){
+         agent{label "release"}
+         steps{
+            sh'''
+            cd ${WORKSPACE}
+            git checkout develop
+            cd tests/gotest
+            bash batchtest.sh
+            cd ${WORKSPACE}/tests/examples/JDBC/JDBCDemo/
+            mvn clean package assembly:single >/dev/null 
+            java -jar target/jdbcChecker-SNAPSHOT-jar-with-dependencies.jar -host 127.0.0.1
+            cd ${WORKSPACE}/tests/examples/python/PYTHONConnectorChecker
+            python3 PythonChecker.py
+            '''
+         }
+       }

      }
    }

  }
+  
 }
--- a/cmake/env.inc
+++ b/cmake/env.inc
@ -45,7 +45,7 @@ IF (${CMAKE_BUILD_TYPE} MATCHES "Debug")
 ELSEIF (${CMAKE_BUILD_TYPE} MATCHES "Release")
  MESSAGE(STATUS "Build Release Version")
 ELSE ()
-  IF (TD_WINDOWS_64)
+  IF (TD_WINDOWS)
    SET(CMAKE_BUILD_TYPE "Release")
    MESSAGE(STATUS "Build Release Version in Windows as default")
  ELSE ()
--- a/cmake/install.inc
+++ b/cmake/install.inc
@ -16,6 +16,7 @@ ELSEIF (TD_WINDOWS)
  INSTALL(DIRECTORY ${TD_COMMUNITY_DIR}/tests/examples DESTINATION .)
  INSTALL(DIRECTORY ${TD_COMMUNITY_DIR}/packaging/cfg DESTINATION .)
  INSTALL(FILES ${TD_COMMUNITY_DIR}/src/inc/taos.h DESTINATION include)
+  INSTALL(FILES ${TD_COMMUNITY_DIR}/src/inc/taoserror.h DESTINATION include)
  INSTALL(FILES ${LIBRARY_OUTPUT_PATH}/taos.lib DESTINATION driver)
  INSTALL(FILES ${LIBRARY_OUTPUT_PATH}/taos.exp DESTINATION driver)
  INSTALL(FILES ${LIBRARY_OUTPUT_PATH}/taos.dll DESTINATION driver) 
@ -30,7 +31,7 @@ ELSEIF (TD_WINDOWS)
  #INSTALL(TARGETS taos RUNTIME DESTINATION driver)
  #INSTALL(TARGETS shell RUNTIME DESTINATION .)
  IF (TD_MVN_INSTALLED)
-    INSTALL(FILES ${LIBRARY_OUTPUT_PATH}/taos-jdbcdriver-2.0.0-dist.jar DESTINATION connector/jdbc)
+    INSTALL(FILES ${LIBRARY_OUTPUT_PATH}/taos-jdbcdriver-2.0.8-dist.jar DESTINATION connector/jdbc)
  ENDIF ()
 ELSEIF (TD_DARWIN)
  SET(TD_MAKE_INSTALL_SH "${TD_COMMUNITY_DIR}/packaging/tools/make_install.sh")
--- 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 "2.0.5.1")
+  SET(TD_VER_NUMBER "2.0.6.0")
 ENDIF ()

 IF (DEFINED VERCOMPATIBLE)
--- a/deps/zlib-1.2.11/inc/zconf.h
+++ b/deps/zlib-1.2.11/inc/zconf.h
@ -472,7 +472,7 @@ typedef uint64_t  z_crc_t;
 #endif
 #ifndef Z_SOLO
 #if defined(Z_HAVE_UNISTD_H) || defined(_LARGEFILE64_SOURCE)
-#if (_WIN64)
+#if defined(_WIN64) || defined(_WIN32)
 #include <io.h>
 #include <process.h>
 #else
--- a/deps/zlib-1.2.11/src/zconf.h
+++ b/deps/zlib-1.2.11/src/zconf.h
@ -472,7 +472,7 @@ typedef uLong FAR uLongf;
 #endif
 #ifndef Z_SOLO
 #  if defined(Z_HAVE_UNISTD_H) || defined(_LARGEFILE64_SOURCE)
-#if (_WIN64)
+#if defined(_WIN64) || defined(_WIN32)
 #include <io.h>
 #include <process.h>
 #else
--- a/documentation/tdenginedocs-cn/advanced-features/index.html
+++ b/documentation/tdenginedocs-cn/advanced-features/index.html
@ -51,8 +51,8 @@ INTERVAL(1M)</code></pre>
 <li><p>mseconds：查询数据库更新的时间间隔，单位为毫秒。一般设置为1000毫秒。返回值为指向TDengine_SUB 结构的指针，如果返回为空，表示失败。</p></li>
 </ul><li><p><code>TAOS_ROW taos_consume(TAOS_SUB *tsub)</code>
 </p><p>该函数用来获取订阅的结果，用户应用程序将其置于一个无限循环语句。如果数据库有新记录到达，该API将返回该最新的记录。如果没有新的记录，该API将阻塞。如果返回值为空，说明系统出错。参数说明：</p></li><ul><li><p>tsub：taos_subscribe的结构体指针。</p></li></ul><li><p><code>void taos_unsubscribe(TAOS_SUB *tsub)</code></p><p>取消订阅。应用程序退出时，务必调用该函数以避免资源泄露。</p></li>
-<li><p><code>int taos_num_subfields(TAOS_SUB *tsub)</code></p><p>获取返回的一行记录中数据包含多少列。</p></li>
-<li><p><code>TAOS_FIELD *taos_fetch_subfields(TAOS_SUB *tsub)</code></p><p>获取每列数据的属性（数据类型、名字、长度），与taos_num_subfileds配合使用，可解析返回的每行数据。</p></li></ul>
+<li><p><code>int taos_num_fields(TAOS_SUB *tsub)</code></p><p>获取返回的一行记录中数据包含多少列。</p></li>
+<li><p><code>TAOS_FIELD *taos_fetch_fields(TAOS_SUB *tsub)</code></p><p>获取每列数据的属性（数据类型、名字、长度），与taos_num_subfileds配合使用，可解析返回的每行数据。</p></li></ul>
 <p>示例代码：请看安装包中的的示范程序</p>
 <a class='anchor' id='缓存-(Cache)'></a><h2>缓存 (Cache)</h2>
 <p>TDengine采用时间驱动缓存管理策略（First-In-First-Out，FIFO），又称为写驱动的缓存管理机制。这种策略有别于读驱动的数据缓存模式（Least-Recent-Use，LRU），直接将最近写入的数据保存在系统的缓存中。当缓存达到临界值的时候，将最早的数据批量写入磁盘。一般意义上来说，对于物联网数据的使用，用户最为关心最近产生的数据，即当前状态。TDengine充分利用了这一特性，将最近到达的（当前状态）数据保存在缓存中。</p>
--- a/documentation/tdenginedocs-cn/connector/index.html
+++ b/documentation/tdenginedocs-cn/connector/index.html
@ -64,9 +64,9 @@
 <p>该API用来获取最新消息，应用程序一般会将其置于一个无限循环语句中。其中参数tsub是taos_subscribe的返回值。如果数据库有新的记录，该API将返回，返回参数是一行记录。如果没有新的记录，该API将阻塞。如果返回值为空，说明系统出错，需要检查系统是否还在正常运行。</p></li>
 <li><p><code>void taos_unsubscribe(TAOS_SUB *tsub)</code></p>
 <p>该API用于取消订阅，参数tsub是taos_subscribe的返回值。应用程序退出时，需要调用该API，否则有资源泄露。</p></li>
-<li><p><code>int taos_num_subfields(TAOS_SUB *tsub)</code></p>
+<li><p><code>int taos_num_fields(TAOS_SUB *tsub)</code></p>
 <p>该API用来获取返回的一排数据中数据的列数</p></li>
-<li><p><code>TAOS_FIELD *taos_fetch_subfields(TAOS_RES *res)</code></p>
+<li><p><code>TAOS_FIELD *taos_fetch_fields(TAOS_RES *res)</code></p>
 <p>该API用来获取每列数据的属性（数据类型、名字、字节数），与taos_num_subfileds配合使用，可用来解析返回的一排数据。</p></li>
 </ul>
 <a class='anchor' id='Java-Connector'></a><h2>Java Connector</h2>
--- a/documentation/tdenginedocs-en/connector/index.html
+++ b/documentation/tdenginedocs-en/connector/index.html
@ -72,9 +72,9 @@ The API is used to start a subscription session by given a handle. The parameter
 The API used to get the new data from a TDengine server. It should be put in an infinite loop. The parameter <em>tsub</em> is the handle returned by <em>taos_subscribe</em>. If new data are updated, the API will return a row of the result. Otherwise, the API is blocked until new data arrives. If <em>NULL</em> pointer is returned, it means an error occurs.</p></li>
 <li><p><code>void taos_unsubscribe(TAOS_SUB *tsub)</code>
 Stop a subscription session by the handle returned by <em>taos_subscribe</em>.</p></li>
-<li><p><code>int taos_num_subfields(TAOS_SUB *tsub)</code>
+<li><p><code>int taos_num_fields(TAOS_SUB *tsub)</code>
 The API used to get the number of fields in a row.</p></li>
-<li><p><code>TAOS_FIELD *taos_fetch_subfields(TAOS_RES *res)</code>
+<li><p><code>TAOS_FIELD *taos_fetch_fields(TAOS_RES *res)</code>
 The API used to get the description of each column.</p></li>
 </ul>
 <a class='anchor' id='Java-Connector'></a><h2>Java Connector</h2>
--- a/documentation20/webdocs/markdowndocs/Evaluation-ch.md
+++ b/documentation20/webdocs/markdowndocs/Evaluation-ch.md
@ -11,7 +11,7 @@ TDengine的模块之一是时序数据库。但除此之外，为减少研发的
 * __全栈时序数据处理引擎__：将数据库、消息队列、缓存、流式计算等功能融为一体，应用无需再集成Kafka/Redis/HBase/Spark/HDFS等软件，大幅降低应用开发和维护的复杂度成本。 
 * __强大的分析功能__：无论是十年前还是一秒钟前的数据，指定时间范围即可查询。数据可在时间轴上或多个设备上进行聚合。即席查询可通过Shell, Python, R, Matlab随时进行。
 * __与第三方工具无缝连接__：不用一行代码，即可与Telegraf, Grafana, EMQ, Prometheus, Matlab, R等集成。后续将支持OPC, Hadoop, Spark等, BI工具也将无缝连接。
-* __零运维成本、零学习成本__：安装、集群一秒搞定，无需分库分表，实时备份。标准SQL，支持JDBC, RESTful, 支持Python/Java/C/C++/Go, 与MySQL相似，零学习成本。
+* __零运维成本、零学习成本__：安装集群简单快捷，无需分库分表，实时备份。类似标准SQL，支持RESTful, 支持Python/Java/C/C++/C#/Go/Node.js, 与MySQL相似，零学习成本。

 采用TDengine，可将典型的物联网、车联网、工业互联网大数据平台的总拥有成本大幅降低。但需要指出的是，因充分利用了物联网时序数据的特点，它无法用来处理网络爬虫、微博、微信、电商、ERP、CRM等通用型数据。

--- a/documentation20/webdocs/markdowndocs/Getting
+++ b/documentation20/webdocs/markdowndocs/Getting
@ -30,13 +30,13 @@ TDengine软件分为服务器、客户端和报警模块三部分，目前2.0版

 - TDengine-alert-2.0.0-Linux-x64.tar.gz (8.1M)

-目前，TDengine只支持在使用[`systemd`](https://en.wikipedia.org/wiki/Systemd)做进程服务管理的linux系统上安装。其他linux系统的支持正在开发中。用`which`命令来检测系统中是否存在`systemd`:
+目前，TDengine只支持在使用[`systemd`](https://en.wikipedia.org/wiki/Systemd)做进程服务管理的linux系统上安装。其他linux系统的支持正在开发中。用`which systemctl`命令来检测系统中是否存在`systemd`包:

 ```cmd
-which systemd
+which systemctl
 ```

-如果系统中不存在`systemd`命令，请考虑[通过源码安装](#通过源码安装)TDengine。
+如果系统中不存在`systemd`包，请考虑[通过源码安装](#通过源码安装)TDengine。

 具体的安装过程，请参见<a href="https://www.taosdata.com/blog/2019/08/09/566.html">TDengine多种安装包的安装和卸载</a>。

--- a/documentation20/webdocs/markdowndocs/Getting
+++ b/documentation20/webdocs/markdowndocs/Getting
@ -16,13 +16,13 @@ Three different packages are provided, please pick up the one you like.
 <li><a id='tdengine-deb' style='color:var(--b2)'>TDengine DEB package (1.7M)</a></li>
 <li><a id='tdengine-tar' style='color:var(--b2)'>TDengine Tarball (3.0M)</a></li>
 </ul>
-For the time being, TDengine only supports installation on Linux systems using [`systemd`](https://en.wikipedia.org/wiki/Systemd) as the service manager. To check if your system has *systemd*, use the _which_ command.
+For the time being, TDengine only supports installation on Linux systems using [`systemd`](https://en.wikipedia.org/wiki/Systemd) as the service manager. To check if your system has *systemd* package, use the _which systemctl_ command.

 ```cmd
-which systemd
+which systemctl
 ```

-If the `systemd` command is not found, please [install from source code](#Install-from-Source). 
+If the `systemd` package is not found, please [install from source code](#Install-from-Source). 

 ### Running TDengine

--- a/documentation20/webdocs/markdowndocs/Queries-ch.md
+++ b/documentation20/webdocs/markdowndocs/Queries-ch.md
@ -29,23 +29,9 @@ Query OK, 2 row(s) in set (0.001100s)
 具体的查询语法请看<a href="https://www.taosdata.com/cn/documentation20/taos-sql/">TAOS SQL </a>。

 ## 多表聚合查询
+物联网场景中，往往同一个类型的数据采集点有多个。TDengine采用超级表(STable)的概念来描述某一个类型的数据采集点，一张普通的表来描述一个具体的数据采集点。同时TDengine使用标签来描述数据采集点的静态属性，一个具体的数据采集点有具体的标签值。通过指定标签的过滤条件，TDengine提供了一高效的方法将超级表(某一类型的数据采集点)所属的子表进行聚合查询。对普通表的聚合函数以及绝大部分操作都适用于超级表，语法完全一样。  

-TDengine对每个数据采集点单独建表，但在实际应用中经常需要对不同的采集点数据进行聚合。为高效的进行聚合操作，TDengine引入超级表（STable）的概念。超级表用来代表一特定类型的数据采集点，它是包含多张表的表集合，集合里每张表的模式（schema）完全一致，但每张表都带有自己的静态标签，标签可以多个，可以随时增加、删除和修改。
-
-应用可通过指定标签的过滤条件，对一个STable下的全部或部分表进行聚合或统计操作，这样大大简化应用的开发。其具体流程如下图所示：
-
-<center> <img src="../assets/stable.png"> </center>
-
-<center> 多表聚合查询原理图  </center>
-
-1：应用将一个查询条件发往系统；2: taosc将超级表的名字发往 Meta Node（管理节点)；3：管理节点将超级表所拥有的 vnode 列表发回 taosc；4：taosc将计算的请求连同标签过滤条件发往这些vnode对应的多个数据节点；5：每个vnode先在内存里查找出自己节点里符合标签过滤条件的表的集合，然后扫描存储的时序数据，完成相应的聚合计算，将结果返回给taosc；6：taosc将多个数据节点返回的结果做最后的聚合，将其返回给应用。
-
-由于TDengine在vnode内将标签数据与时序数据分离存储，通过先在内存里过滤标签数据，将需要扫描的数据集大幅减少，大幅提升聚合计算速度。同时，由于数据分布在多个vnode/dnode，聚合计算操作在多个vnode里并发进行，又进一步提升了聚合的速度。
-
-对普通表的聚合函数以及绝大部分操作都适用于超级表，语法完全一样，细节请看 TAOS SQL。
-
-比如：在TAOS Shell，查找所有智能电表采集的电压平均值，并按照location分组
-
+**示例1**：在TAOS Shell，查找北京所有智能电表采集的电压平均值，并按照location分组
 ```mysql
 taos> SELECT AVG(voltage) FROM meters GROUP BY location;
       avg(voltage)        |            location            |
@ -55,6 +41,18 @@ taos> SELECT AVG(voltage) FROM meters GROUP BY location;
 Query OK, 2 row(s) in set (0.002136s)
 ```

+**示例2**：在TAOS shell, 查找groupId为2的所有智能电表过去24小时的记录条数，电流的最大值
+
+```mysql
+taos> SELECT count(*), max(current) FROM meters where groupId = 2 and ts > now - 24h;
+     cunt(*)  |    max(current)  |
+==================================
+            5 |             13.4 |
+Query OK, 1 row(s) in set (0.002136s)
+```
+
+TDengine仅容许对属于同一个超级表的表之间进行聚合查询，不同超级表之间的聚合查询不支持。在<a href="https://www.taosdata.com/cn/documentation20/taos-sql/">TAOS SQL </a>一章，查询类操作都会注明是否支持超级表。
+
 ## 降采样查询、插值

 物联网场景里，经常需要通过降采样（down sampling）将采集的数据按时间段进行聚合。TDengine 提供了一个简便的关键词 interval 让按照时间窗口的查询操作变得极为简单。比如，将智能电表 d1001 采集的电流值每10秒钟求和
@ -66,9 +64,9 @@ taos> SELECT sum(current) FROM d1001 INTERVAL(10s);
 2018-10-03 14:38:10.000 |              24.900000572 |
 Query OK, 2 row(s) in set (0.000883s)
 ```
-降采样操作也适用于超级表，比如：将所有智能电表采集的电流值每秒钟求和
+降采样操作也适用于超级表，比如：将北京所有智能电表采集的电流值每秒钟求和
 ```mysql
-taos> SELECT SUM(current) FROM meters INTERVAL(1s);
+taos> SELECT SUM(current) FROM meters where location like "Beijing%" INTERVAL(1s);
           ts            |       sum(current)        |
 ======================================================
 2018-10-03 14:38:04.000 |              10.199999809 |
--- a/documentation20/webdocs/markdowndocs/TAOS
+++ b/documentation20/webdocs/markdowndocs/TAOS
@ -125,6 +125,7 @@ TDengine缺省的时间戳是毫秒精度，但通过修改配置参数enableMic
    1) 表的第一个字段必须是TIMESTAMP，并且系统自动将其设为主键；
    2) 表名最大长度为193；
    3) 表的每行长度不能超过16k个字符;
+    4) 子表名只能由字母、数字和下划线组成，且不能以数字开头
    5) 使用数据类型binary或nchar，需指定其最长的字节数，如binary(20)，表示20字节；

 - **删除数据表**
--- a/documentation20/webdocs/markdowndocs/administrator-ch.md
+++ b/documentation20/webdocs/markdowndocs/administrator-ch.md
@ -82,8 +82,7 @@ TDengine系统后台服务由taosd提供，可以在配置文件taos.cfg里修

 下面仅仅列出一些重要的配置参数，更多的参数请看配置文件里的说明。各个参数的详细介绍及作用请看前述章节，而且这些参数的缺省配置都是工作的，一般无需设置。**注意：配置修改后，需要重启*taosd*服务才能生效。**

- firstEp: taosd启动时，主动连接的集群中第一个dnode的end point, 默认值为localhost:6030。
- secondEp: taosd启动时，如果first连接不上，尝试连接集群中第二个dnode的end point, 默认值为空。
+- firstEp: taosd启动时，主动连接的集群中首个dnode的end point, 默认值为localhost:6030。
 - fqdn：数据节点的FQDN，缺省为操作系统配置的第一个hostname。如果习惯IP地址访问，可设置为该节点的IP地址。
 - serverPort：taosd启动后，对外服务的端口号，默认值为6030。
 - httpPort: RESTful服务使用的端口号，所有的HTTP请求（TCP）都需要向该接口发起查询/写入请求, 默认值为6041。
@ -156,76 +155,80 @@ TDengine系统的前台交互客户端应用程序为taos，它与taosd共享同
 客户端配置参数

 - firstEp: taos启动时，主动连接的集群中第一个taosd实例的end point, 缺省值为 localhost:6030。
- secondEp: taos启动时，如果first连接不上，尝试连接集群中第二个taosd实例的end point, 缺省值为空。
 - locale

-    > 默认值：系统中动态获取，如果自动获取失败，需要用户在配置文件设置或通过API设置
+    默认值：系统中动态获取，如果自动获取失败，需要用户在配置文件设置或通过API设置
    
-TDengine为存储中文、日文、韩文等非ASCII编码的宽字符，提供一种专门的字段类型nchar。写入nchar字段的数据将统一采用UCS4-LE格式进行编码并发送到服务器。需要注意的是，编码正确性是客户端来保证。因此，如果用户想要正常使用nchar字段来存储诸如中文、日文、韩文等非ASCII字符，需要正确设置客户端的编码格式。
+    TDengine为存储中文、日文、韩文等非ASCII编码的宽字符，提供一种专门的字段类型nchar。写入nchar字段的数据将统一采用UCS4-LE格式进行编码并发送到服务器。需要注意的是，编码正确性是客户端来保证。因此，如果用户想要正常使用nchar字段来存储诸如中文、日文、韩文等非ASCII字符，需要正确设置客户端的编码格式。

-客户端的输入的字符均采用操作系统当前默认的编码格式，在Linux系统上多为UTF-8，部分中文系统编码则可能是GB18030或GBK等。在docker环境中默认的编码是POSIX。在中文版Windows系统中，编码则是CP936。客户端需要确保正确设置自己所使用的字符集，即客户端运行的操作系统当前编码字符集，才能保证nchar中的数据正确转换为UCS4-LE编码格式。
+    客户端的输入的字符均采用操作系统当前默认的编码格式，在Linux系统上多为UTF-8，部分中文系统编码则可能是GB18030或GBK等。在docker环境中默认的编码是POSIX。在中文版Windows系统中，编码则是CP936。客户端需要确保正确设置自己所使用的字符集，即客户端运行的操作系统当前编码字符集，才能保证nchar中的数据正确转换为UCS4-LE编码格式。

-在 Linux 中 locale 的命名规则为: <语言>_<地区>.<字符集编码> 如：zh_CN.UTF-8，zh代表中文，CN代表大陆地区，UTF-8表示字符集。字符集编码为客户端正确解析本地字符串提供编码转换的说明。Linux系统与 Mac OSX 系统可以通过设置locale来确定系统的字符编码，由于Windows使用的locale中不是POSIX标准的locale格式，因此在Windows下需要采用另一个配置参数charset来指定字符编码。在Linux 系统中也可以使用charset来指定字符编码。
+    在 Linux 中 locale 的命名规则为: <语言>_<地区>.<字符集编码> 如：zh_CN.UTF-8，zh代表中文，CN代表大陆地区，UTF-8表示字符集。字符集编码为客户端正确解析本地字符串提供编码转换的说明。Linux系统与 Mac OSX 系统可以通过设置locale来确定系统的字符编码，由于Windows使用的locale中不是POSIX标准的locale格式，因此在Windows下需要采用另一个配置参数charset来指定字符编码。在Linux 系统中也可以使用charset来指定字符编码。

 - charset

-    > 默认值：系统中动态获取，如果自动获取失败，需要用户在配置文件设置或通过API设置
+    默认值：系统中动态获取，如果自动获取失败，需要用户在配置文件设置或通过API设置
    
-如果配置文件中不设置charset，在Linux系统中，taos在启动时候，自动读取系统当前的locale信息，并从locale信息中解析提取charset编码格式。如果自动读取locale信息失败，则尝试读取charset配置，如果读取charset配置也失败，则中断启动过程。
+    如果配置文件中不设置charset，在Linux系统中，taos在启动时候，自动读取系统当前的locale信息，并从locale信息中解析提取charset编码格式。如果自动读取locale信息失败，则尝试读取charset配置，如果读取charset配置也失败，则中断启动过程。

-在Linux系统中，locale信息包含了字符编码信息，因此正确设置了Linux系统locale以后可以不用再单独设置charset。例如：
-```
+    在Linux系统中，locale信息包含了字符编码信息，因此正确设置了Linux系统locale以后可以不用再单独设置charset。例如：
+    ```
    locale zh_CN.UTF-8
-```
-在Windows系统中，无法从locale获取系统当前编码。如果无法从配置文件中读取字符串编码信息，taos默认设置为字符编码为CP936。其等效在配置文件中添加如下配置：
-```
+    ```
+    在Windows系统中，无法从locale获取系统当前编码。如果无法从配置文件中读取字符串编码信息，taos默认设置为字符编码为CP936。其等效在配置文件中添加如下配置：
+    ```
    charset CP936
-```
-如果需要调整字符编码，请查阅当前操作系统使用的编码，并在配置文件中正确设置。
+    ```
+    如果需要调整字符编码，请查阅当前操作系统使用的编码，并在配置文件中正确设置。

-在Linux系统中，如果用户同时设置了locale和字符集编码charset，并且locale和charset的不一致，后设置的值将覆盖前面设置的值。
-```
+    在Linux系统中，如果用户同时设置了locale和字符集编码charset，并且locale和charset的不一致，后设置的值将覆盖前面设置的值。
+    ```
    locale zh_CN.UTF-8
    charset GBK
-```
-则charset的有效值是GBK。
-```
+    ```
+    则charset的有效值是GBK。
+    ```
    charset GBK
    locale zh_CN.UTF-8
-```
-charset的有效值是UTF-8。
+    ```
+    charset的有效值是UTF-8。

-日志的配置参数，与server 的配置参数完全一样。
+    日志的配置参数，与server 的配置参数完全一样。

 - timezone

    默认值：从系统中动态获取当前的时区设置

-客户端运行系统所在的时区。为应对多时区的数据写入和查询问题，TDengine 采用 Unix 时间戳(Unix Timestamp)来记录和存储时间戳。Unix 时间戳的特点决定了任一时刻不论在任何时区，产生的时间戳均一致。需要注意的是，Unix时间戳是在客户端完成转换和记录。为了确保客户端其他形式的时间转换为正确的 Unix 时间戳，需要设置正确的时区。
+    客户端运行系统所在的时区。为应对多时区的数据写入和查询问题，TDengine 采用 Unix 时间戳(Unix Timestamp)来记录和存储时间戳。Unix 时间戳的特点决定了任一时刻不论在任何时区，产生的时间戳均一致。需要注意的是，Unix时间戳是在客户端完成转换和记录。为了确保客户端其他形式的时间转换为正确的 Unix 时间戳，需要设置正确的时区。

-在Linux系统中，客户端会自动读取系统设置的时区信息。用户也可以采用多种方式在配置文件设置时区。例如：
-```
+    在Linux系统中，客户端会自动读取系统设置的时区信息。用户也可以采用多种方式在配置文件设置时区。例如：
+    ```
    timezone UTC-8
    timezone GMT-8
    timezone Asia/Shanghai
-```
-均是合法的设置东八区时区的格式。
+    ```
+    均是合法的设置东八区时区的格式。

-时区的设置对于查询和写入SQL语句中非Unix时间戳的内容（时间戳字符串、关键词now的解析）产生影响。例如：
-```
+    时区的设置对于查询和写入SQL语句中非Unix时间戳的内容（时间戳字符串、关键词now的解析）产生影响。例如：
+    ```
    SELECT count(*) FROM table_name WHERE TS<'2019-04-11 12:01:08';
-```
-在东八区，SQL语句等效于
-```
+    ```
+    在东八区，SQL语句等效于
+    ```
    SELECT count(*) FROM table_name WHERE TS<1554955268000;
-```
-在UTC时区，SQL语句等效于
-```
+    ```
+    在UTC时区，SQL语句等效于
+    ```
    SELECT count(*) FROM table_name WHERE TS<1554984068000;
-```
-为了避免使用字符串时间格式带来的不确定性，也可以直接使用Unix时间戳。此外，还可以在SQL语句中使用带有时区的时间戳字符串，例如：RFC3339格式的时间戳字符串，2013-04-12T15:52:01.123+08:00或者ISO-8601格式时间戳字符串2013-04-12T15:52:01.123+0800。上述两个字符串转化为Unix时间戳不受系统所在时区的影响。
+    ```
+    为了避免使用字符串时间格式带来的不确定性，也可以直接使用Unix时间戳。此外，还可以在SQL语句中使用带有时区的时间戳字符串，例如：RFC3339格式的时间戳字符串，2013-04-12T15:52:01.123+08:00或者ISO-8601格式时间戳字符串2013-04-12T15:52:01.123+0800。上述两个字符串转化为Unix时间戳不受系统所在时区的影响。
+
+    启动taos时，也可以从命令行指定一个taosd实例的end point，否则就从taos.cfg读取。
+   
+- maxBinaryDisplayWidth
+
+    Shell中binary 和 nchar字段的显示宽度上限，超过此限制的部分将被隐藏。默认值：30。可在 shell 中通过命令 set max_binary_display_width nn 动态修改此选项。
   
-启动taos时，也可以从命令行指定一个taosd实例的end point，否则就从taos.cfg读取。

 ## 用户管理

@ -378,7 +381,7 @@ KILL STREAM <stream-id>;

 ## 系统监控

-TDengine启动后，会自动创建一个监测数据库SYS，并自动将服务器的CPU、内存、硬盘空间、带宽、请求数、磁盘读写速度、慢查询等信息定时写入该数据库。TDengine还将重要的系统操作（比如登录、创建、删除数据库等）日志以及各种错误报警信息记录下来存放在SYS库里。系统管理员可以从CLI直接查看这个数据库，也可以在WEB通过图形化界面查看这些监测信息。
+TDengine启动后，会自动创建一个监测数据库log，并自动将服务器的CPU、内存、硬盘空间、带宽、请求数、磁盘读写速度、慢查询等信息定时写入该数据库。TDengine还将重要的系统操作（比如登录、创建、删除数据库等）日志以及各种错误报警信息记录下来存放在log库里。系统管理员可以从CLI直接查看这个数据库，也可以在WEB通过图形化界面查看这些监测信息。

 这些监测信息的采集缺省是打开的，但可以修改配置文件里的选项enableMonitor将其关闭或打开。

@ -408,5 +411,4 @@ TDengine的所有可执行文件默认存放在 _/usr/local/taos/bin_ 目录下

 您可以通过修改系统配置文件taos.cfg来配置不同的数据目录和日志目录。

-##

--- a/documentation20/webdocs/markdowndocs/architecture-ch.md
+++ b/documentation20/webdocs/markdowndocs/architecture-ch.md
@ -65,24 +65,24 @@ TDengine 的设计是基于单个硬件、软件系统不可靠，基于任何
 TDengine 分布式架构的逻辑结构图如下：
 <center> <img src="../assets/structure.png"> </center>
 <center> 图 1 TDengine架构示意图  </center>
-一个完整的 TDengine 系统是运行在一到多个物理节点上的，逻辑上，它包含数据节点(dnode)、TDengine客户端(taosc)以及应用(app)。系统中存在一到多个数据节点，这些数据节点组成一个集群(cluster)。应用通过taosc的API与TDengine集群进行互动。下面对每个逻辑单元进行简要介绍。
+一个完整的 TDengine 系统是运行在一到多个物理节点上的，逻辑上，它包含数据节点(dnode)、TDengine应用驱动(taosc)以及应用(app)。系统中存在一到多个数据节点，这些数据节点组成一个集群(cluster)。应用通过taosc的API与TDengine集群进行互动。下面对每个逻辑单元进行简要介绍。

-**物理节点(pnode):** pnode是一独立运行、拥有自己的计算、存储和网络能力的计算机，可以是安装有OS的物理机、虚拟机或容器。物理节点由其配置的 FQDN(Fully Qualified Domain Name)来标识。TDengine完全依赖FQDN来进行网络通讯，如果不了解FQDN，请看博文《[一篇文章说清楚TDengine的FQDN](https://www.taosdata.com/blog/2020/09/11/1824.html)》。
+**物理节点(pnode):** pnode是一独立运行、拥有自己的计算、存储和网络能力的计算机，可以是安装有OS的物理机、虚拟机或Docker容器。物理节点由其配置的 FQDN(Fully Qualified Domain Name)来标识。TDengine完全依赖FQDN来进行网络通讯，如果不了解FQDN，请看博文《[一篇文章说清楚TDengine的FQDN](https://www.taosdata.com/blog/2020/09/11/1824.html)》。

 **数据节点(dnode):** dnode 是 TDengine 服务器侧执行代码 taosd 在物理节点上的一个运行实例，一个工作的系统必须有至少一个数据节点。dnode包含零到多个逻辑的虚拟节点(VNODE)，零或者至多一个逻辑的管理节点(mnode)。dnode在系统中的唯一标识由实例的End Point (EP )决定。EP是dnode所在物理节点的FQDN (Fully Qualified Domain Name)和系统所配置的网络端口号(Port)的组合。通过配置不同的端口，一个物理节点(一台物理机、虚拟机或容器）可以运行多个实例，或有多个数据节点。

-**虚拟节点(vnode)**: 为更好的支持数据分片、负载均衡，防止数据过热或倾斜，数据节点被虚拟化成多个虚拟节点(vnode，图中V2, V3, V4等)。每个 vnode 都是一个相对独立的工作单元，是时序数据存储的基本单元，具有独立的运行线程、内存空间与持久化存储的路径。一个 vnode 包含一定数量的表（数据采集点）。当创建一张新表时，系统会检查是否需要创建新的 vnode。一个数据节点上能创建的 vnode 的数量取决于该数据节点所在物理节点的硬件资源。一个 vnode 只属于一个DB，但一个DB可以有多个 vnode。一个 vnode 除存储的时序数据外，也保存有所包含的表的SCHEMA、标签值等。一个虚拟节点由所属的数据节点的EP，以及所属的VGroup ID在系统内唯一标识，由管理节点创建并管理。
+**虚拟节点(vnode)**: 为更好的支持数据分片、负载均衡，防止数据过热或倾斜，数据节点被虚拟化成多个虚拟节点(vnode，图中V2, V3, V4等)。每个 vnode 都是一个相对独立的工作单元，是时序数据存储的基本单元，具有独立的运行线程、内存空间与持久化存储的路径。一个 vnode 包含一定数量的表（数据采集点）。当创建一张新表时，系统会检查是否需要创建新的 vnode。一个数据节点上能创建的 vnode 的数量取决于该数据节点所在物理节点的硬件资源。一个 vnode 只属于一个DB，但一个DB可以有多个 vnode。一个 vnode 除存储的时序数据外，也保存有所包含的表的schema、标签值等。一个虚拟节点由所属的数据节点的EP，以及所属的VGroup ID在系统内唯一标识，由管理节点创建并管理。

 **管理节点(mnode):** 一个虚拟的逻辑单元，负责所有数据节点运行状态的监控和维护，以及节点之间的负载均衡(图中M)。同时，管理节点也负责元数据(包括用户、数据库、表、静态标签等)的存储和管理，因此也称为 Meta Node。TDengine 集群中可配置多个(最多不超过5个) mnode，它们自动构建成为一个虚拟管理节点组(图中M0, M1, M2)。mnode 间采用 master/slave 的机制进行管理，而且采取强一致方式进行数据同步, 任何数据更新操作只能在 Master 上进行。mnode 集群的创建由系统自动完成，无需人工干预。每个dnode上至多有一个mnode，由所属的数据节点的EP来唯一标识。每个dnode通过内部消息交互自动获取整个集群中所有 mnode 所在的 dnode 的EP。

 **虚拟节点组(VGroup):** 不同数据节点上的 vnode 可以组成一个虚拟节点组(vnode group)来保证系统的高可靠。虚拟节点组内采取master/slave的方式进行管理。写操作只能在 master vnode 上进行，系统采用异步复制的方式将数据同步到 slave vnode，这样确保了一份数据在多个物理节点上有拷贝。一个 vgroup 里虚拟节点个数就是数据的副本数。如果一个DB的副本数为N，系统必须有至少N个数据节点。副本数在创建DB时通过参数 replica 可以指定，缺省为1。使用 TDengine 的多副本特性，可以不再需要昂贵的磁盘阵列等存储设备，就可以获得同样的数据高可靠性。虚拟节点组由管理节点创建、管理，并且由管理节点分配一个系统唯一的ID，VGroup ID。如果两个虚拟节点的vnode group ID相同，说明他们属于同一个组，数据互为备份。虚拟节点组里虚拟节点的个数是可以动态改变的，容许只有一个，也就是没有数据复制。VGroup ID是永远不变的，即使一个虚拟节点组被删除，它的ID也不会被收回重复利用。

-**TAOSC:** taosc是TDengine给应用提供的驱动程序(driver)，负责处理应用与集群的接口交互，内嵌于JDBC、ODBC driver中，或者C、Python、Go语言连接库里。应用都是通过taosc而不是直接连接集群中的数据节点与整个集群进行交互的。这个模块负责获取并缓存元数据；将插入、查询等请求转发到正确的数据节点；在把结果返回给应用时，还需要负责最后一级的聚合、排序、过滤等操作。对于JDBC, ODBC, C/C++接口而言，这个模块是在应用所处的物理节点上运行，但消耗的资源很小。同时，为支持全分布式的RESTful接口，taosc在TDengine集群的每个dnode上都有一运行实例。
+**TAOSC:** taosc是TDengine给应用提供的驱动程序(driver)，负责处理应用与集群的接口交互，提供C/C++语言原生接口，内嵌于JDBC、C#、Python、Go、Node.js语言连接库里。应用都是通过taosc而不是直接连接集群中的数据节点与整个集群进行交互的。这个模块负责获取并缓存元数据；将插入、查询等请求转发到正确的数据节点；在把结果返回给应用时，还需要负责最后一级的聚合、排序、过滤等操作。对于JDBC, C/C++/C#/Python/Go/Node.js接口而言，这个模块是在应用所处的物理节点上运行。同时，为支持全分布式的RESTful接口，taosc在TDengine集群的每个dnode上都有一运行实例。

 ### 节点之间的通讯
-**通讯方式：**TDengine系统的各个节点之间的通讯是通过TCP/UDP进行的。因为考虑到物联网场景，数据写入的包一般不大，因此TDengine 除采用TCP做传输之外，还采用UDP方式，因为UDP 更加高效，而且不受连接数的限制。TDengine实现了自己的超时、重传、确认等机制，以确保UDP的可靠传输。对于数据量不到15K的数据包，采取UDP的方式进行传输，超过15K的，或者是查询类的操作，自动采取TCP的方式进行传输。同时，TDengine根据配置和数据包，会自动对数据进行压缩/解压缩，数字签名/认证等处理。对于数据节点之间的数据复制，只采用TCP方式进行数据传输。
+**通讯方式：**TDengine系统的各个数据节点之间，以及应用驱动与各数据节点之间的通讯是通过TCP/UDP进行的。因为考虑到物联网场景，数据写入的包一般不大，因此TDengine 除采用TCP做传输之外，还采用UDP方式，因为UDP 更加高效，而且不受连接数的限制。TDengine实现了自己的超时、重传、确认等机制，以确保UDP的可靠传输。对于数据量不到15K的数据包，采取UDP的方式进行传输，超过15K的，或者是查询类的操作，自动采取TCP的方式进行传输。同时，TDengine根据配置和数据包，会自动对数据进行压缩/解压缩，数字签名/认证等处理。对于数据节点之间的数据复制，只采用TCP方式进行数据传输。

-**FQDN配置**：一个数据节点有一个或多个FQDN，可以在系统配置文件taos.cfg通过参数“fqdn"进行指定，如果没有指定，系统将自动获取FQDN。如果节点没有配置FQDN，可以直接将该节点的配置参数fqdn设置为它的IP地址。但不建议使用IP，因为IP地址可变，一旦变化，将让集群无法正常工作。一个数据节点的EP(End Point)由FQDN + Port组成。采用FQDN，需要保证DNS服务正常工作，或者在节点以及应用所在的节点配置好hosts文件。
+**FQDN配置**：一个数据节点有一个或多个FQDN，可以在系统配置文件taos.cfg通过参数“fqdn"进行指定，如果没有指定，系统将自动获取计算机的hostname作为其FQDN。如果节点没有配置FQDN，可以直接将该节点的配置参数fqdn设置为它的IP地址。但不建议使用IP，因为IP地址可变，一旦变化，将让集群无法正常工作。一个数据节点的EP(End Point)由FQDN + Port组成。采用FQDN，需要保证DNS服务正常工作，或者在节点以及应用所在的节点配置好hosts文件。

 **端口配置：**一个数据节点对外的端口由TDengine的系统配置参数serverPort决定，对集群内部通讯的端口是serverPort+5。集群内数据节点之间的数据复制操作还占有一个TCP端口，是serverPort+10. 为支持多线程高效的处理UDP数据，每个对内和对外的UDP连接，都需要占用5个连续的端口。因此一个数据节点总的端口范围为serverPort到serverPort + 10，总共11个TCP/UDP端口。使用时，需要确保防火墙将这些端口打开。每个数据节点可以配置不同的serverPort。

@ -153,6 +153,7 @@ TDengine除vnode分片之外，还对时序数据按照时间段进行分区。
 当新的数据节点被添加进集群，因为新的计算和存储被添加进来，系统也将自动启动负载均衡流程。

 负载均衡过程无需任何人工干预，应用也无需重启，将自动连接新的节点，完全透明。
+**提示：负载均衡由参数balance控制，决定开启/关闭自动负载均衡。**

 ## 数据写入与复制流程
 如果一个数据库有N个副本，那一个虚拟节点组就有N个虚拟节点，但是只有一个是Master，其他都是slave。当应用将新的记录写入系统时，只有Master vnode能接受写的请求。如果slave vnode收到写的请求，系统将通知taosc需要重新定向。
@ -192,7 +193,8 @@ Master Vnode遵循下面的写入流程：

 理论上，只要是异步复制，就无法保证100%不丢失。但是这个窗口极小，mater与slave要同时发生故障，而且发生在刚给应用确认写入成功之后。

-注：异地容灾、IDC无中断迁移，仅仅企业版支持
+注：异地容灾、IDC无中断迁移，仅仅企业版支持。
+**提示：该功能暂未提供**

 ### 主从选择
 Vnode会保持一个数据版本号(Version)，对内存数据进行持久化存储时，对该版本号也进行持久化存储。每个数据更新操作，无论是采集的时序数据还是元数据，这个版本号将增一。
@ -259,6 +261,7 @@ dataDir /mnt/disk6/taos 2
 挂载的盘也可以是非本地的网络盘，只要系统能访问即可。

 注：多级存储功能仅企业版支持
+**提示：该功能暂未提供**

 ## 数据查询
 TDengine提供了多种多样针对表和超级表的查询处理功能，除了常规的聚合查询之外，还提供针对时序数据的窗口查询、统计聚合等功能。TDengine的查询处理需要客户端、vnode, mnode节点协同完成。
@ -289,11 +292,18 @@ select count(*) from d1001 interval(1h) fill(prev);
 针对d1001设备采集数据统计每小时记录数，如果某一个小时不存在数据，这返回之前一个小时的统计数据。TDengine提供前向插值(prev)、线性插值(linear)、NULL值填充(NULL)、特定值填充(value)。

 ### 多表聚合查询
-多表聚合查询与单表查询的整体流程相同，但是存在如下的差异：
+TDengine对每个数据采集点单独建表，但在实际应用中经常需要对不同的采集点数据进行聚合。为高效的进行聚合操作，TDengine引入超级表（STable）的概念。超级表用来代表一特定类型的数据采集点，它是包含多张表的表集合，集合里每张表的模式（schema）完全一致，但每张表都带有自己的静态标签，标签可以多个，可以随时增加、删除和修改。 应用可通过指定标签的过滤条件，对一个STable下的全部或部分表进行聚合或统计操作，这样大大简化应用的开发。其具体流程如下图所示：
+<center> <img src="../assets/multi_tables.png">  </center>

- 由于多表可能分布在不同的节点(dnode)，因此多表的聚合查询需要首先获得表所在的全部数据节点的信息，并且同时向相关的dnode发出查询请求。
- 每个vnode的计算获得的中间结果(partial results)需要进行第二阶段的聚合才能形成最终结果，第二阶段的聚合过程在客户端完成。
- 由于表标签信息存储在vnode中，因此针对标签信息的查询也需要vnode完成。客户端将标签的过滤表达式封装在查询请求结构体中发送给vnode，由vnode的查询执行线程从中抽取出标签查询条件，然后执行查询。标签查询与过滤是在针对表的查询之前完成。标签查询完成以后，将符合条件的表纳入到接下来的查询处理流程中。
+<center> 图 5 多表聚合查询原理图  </center>
+1：应用将一个查询条件发往系统；
+2: taosc将超级表的名字发往 Meta Node（管理节点)；
+3：管理节点将超级表所拥有的 vnode 列表发回 taosc；
+4：taosc将计算的请求连同标签过滤条件发往这些vnode对应的多个数据节点；
+5：每个vnode先在内存里查找出自己节点里符合标签过滤条件的表的集合，然后扫描存储的时序数据，完成相应的聚合计算，将结果返回给taosc；
+6：taosc将多个数据节点返回的结果做最后的聚合，将其返回给应用。 
+
+由于TDengine在vnode内将标签数据与时序数据分离存储，通过在内存里过滤标签数据，先找到需要参与聚合操作的表的集合，将需要扫描的数据集大幅减少，大幅提升聚合计算速度。同时，由于数据分布在多个vnode/dnode，聚合计算操作在多个vnode里并发进行，又进一步提升了聚合的速度。 对普通表的聚合函数以及绝大部分操作都适用于超级表，语法完全一样，细节请看 TAOS SQL。

 ### 预计算
 为有效提升查询处理的性能，针对物联网数据的不可更改的特点，在数据块头部记录该数据块中存储数据的统计信息：包括最大值、最小值、和。我们称之为预计算单元。如果查询处理涉及整个数据块的全部数据，直接使用预计算结果，完全不需要读取数据块的内容。由于预计算数据量远小于磁盘上存储的数据块数据的大小，对于磁盘IO为瓶颈的查询处理，使用预计算结果可以极大地减小读取IO压力，加速查询处理的流程。预计算机制与Postgre SQL的索引BRIN（block range index）有异曲同工之妙。
--- a/documentation20/webdocs/markdowndocs/cluster-ch.md
+++ b/documentation20/webdocs/markdowndocs/cluster-ch.md
@ -8,7 +8,7 @@ TDengine的集群管理极其简单，除添加和删除节点需要人工干预

 ## 准备工作

-**第零步**：如果没有部署DNS服务，请规划集群所有物理节点的FQDN，然后按照《[一篇文章说清楚TDengine的FQDN](https://www.taosdata.com/blog/2020/09/11/1824.html)》里的步骤，将所有集群物理节点的IP与FQDN的对应关系添加好。
+**第零步**：规划集群所有物理节点的FQDN，将规划好的FQDN分别添加到每个物理节点的/etc/hostname；修改每个物理节点的/etc/hosts，将所有集群物理节点的IP与FQDN的对应添加好。【如部署了DNS，请联系网络管理员在DNS上做好相关配置】

 **第一步**：如果搭建集群的物理节点中，存有之前的测试数据、装过1.X的版本，或者装过其他版本的TDengine，请先将其删除，并清空所有数据，具体步骤请参考博客[《TDengine多种安装包的安装和卸载》](https://www.taosdata.com/blog/2019/08/09/566.html ) 
 **注意1：**因为FQDN的信息会写进文件，如果之前没有配置或者更改FQDN，且启动了TDengine。请一定在确保数据无用或者备份的前提下，清理一下之前的数据（rm -rf /var/lib/taos/）；
@ -16,9 +16,9 @@ TDengine的集群管理极其简单，除添加和删除节点需要人工干预

 **第二步**：建议关闭所有物理节点的防火墙，至少保证端口：6030 - 6042的TCP和UDP端口都是开放的。**强烈建议**先关闭防火墙，集群搭建完毕之后，再来配置端口；

-**第三步**：在所有节点安装TDengine，且版本必须是一致的，**但不要启动taosd**。安装时，提示输入是否要加入一个已经存在的TDengine集群时，第一个物理节点直接回车创建新集群，后续物理节点则输入该集群任何一个在线的物理节点的FQDN:端口号(默认6030)；
+**第三步**：在所有物理节点安装TDengine，且版本必须是一致的，**但不要启动taosd**。安装时，提示输入是否要加入一个已经存在的TDengine集群时，第一个物理节点直接回车创建新集群，后续物理节点则输入该集群任何一个在线的物理节点的FQDN:端口号(默认6030)；

-**第四步**：检查所有数据节点，以及应用所在物理节点的网络设置：
+**第四步**：检查所有数据节点，以及应用程序所在物理节点的网络设置：

 1. 每个物理节点上执行命令`hostname -f`，查看和确认所有节点的hostname是不相同的(应用驱动所在节点无需做此项检查)；
 2. 每个物理节点上执行`ping host`, 其中host是其他物理节点的hostname, 看能否ping通其它物理节点; 如果不能ping通，需要检查网络设置, 或/etc/hosts文件(Windows系统默认路径为C:\Windows\system32\drivers\etc\hosts)，或DNS的配置。如果无法ping通，是无法组成集群的；
@ -213,6 +213,6 @@ SHOW MNODES;

 ## Arbitrator的使用

-如果副本数为偶数，当一个vnode group里一半或超过一半的vnode不工作时，是无法从中选出master的。同理，一半或超过一半的mnode不工作时，是无法选出mnode的master的，因为存在“split brain”问题。为解决这个问题，TDengine引入了arbitrator的概念。Arbitrator模拟一个vnode或mnode在工作，但只简单的负责网络连接，不处理任何数据插入或访问。只要包含arbitrator在内，超过半数的vnode或mnode工作，那么该vnode group或mnode组就可以正常的提供数据插入或查询服务。比如对于副本数为2的情形，如果一个节点A离线，但另外一个节点B正常，而且能连接到arbitrator, 那么节点B就能正常工作。
+如果副本数为偶数，当一个vnode group里一半vnode不工作时，是无法从中选出master的。同理，一半mnode不工作时，是无法选出mnode的master的，因为存在“split brain”问题。为解决这个问题，TDengine引入了arbitrator的概念。Arbitrator模拟一个vnode或mnode在工作，但只简单的负责网络连接，不处理任何数据插入或访问。只要包含arbitrator在内，超过半数的vnode或mnode工作，那么该vnode group或mnode组就可以正常的提供数据插入或查询服务。比如对于副本数为2的情形，如果一个节点A离线，但另外一个节点B正常，而且能连接到arbitrator, 那么节点B就能正常工作。

-TDengine安装包里带有一个执行程序tarbitrator, 找任何一台Linux服务器运行它即可。该程序对系统资源几乎没有要求，只需要保证有网络连接即可。该应用的命令行参数`-p`可以指定其对外服务的端口号，缺省是6042。配置每个taosd实例时，可以在配置文件taos.cfg里将参数arbitrator设置为arbitrator的End Point。如果该参数配置了，当副本数为偶数数，系统将自动连接配置的arbitrator。
+TDengine提供一个执行程序tarbitrator, 找任何一台Linux服务器运行它即可。请点击[安装包下载](https://www.taosdata.com/cn/all-downloads/)，在TDengine Arbitrator Linux一节中，选择适合的版本下载并安装。该程序对系统资源几乎没有要求，只需要保证有网络连接即可。该应用的命令行参数`-p`可以指定其对外服务的端口号，缺省是6042。配置每个taosd实例时，可以在配置文件taos.cfg里将参数arbitrator设置为arbitrator的End Point。如果该参数配置了，当副本数为偶数数，系统将自动连接配置的arbitrator。如果副本数为奇数，即使配置了arbitrator, 系统也不会去建立连接。
--- a/documentation20/webdocs/markdowndocs/connector-java-ch.md
+++ b/documentation20/webdocs/markdowndocs/connector-java-ch.md
@ -72,38 +72,34 @@ maven 项目中使用如下 pom.xml 配置即可：

 ### 获取连接

-如下所示配置即可获取 TDengine Connection：
+#### 通过JdbcUrl获取连接
+
+通过指定的jdbcUrl获取连接，如下所示：
 ```java
 Class.forName("com.taosdata.jdbc.TSDBDriver");
-String jdbcUrl = "jdbc:TAOS://127.0.0.1:6030/log?user=root&password=taosdata";
+String jdbcUrl = "jdbc:TAOS://taosdemo.com:6030/test?user=root&password=taosdata";
 Connection conn = DriverManager.getConnection(jdbcUrl);
 ```
-> 端口 6030 为默认连接端口，JDBC URL 中的 log 为系统本身的监控数据库。
+以上示例，建立了到hostname为taosdemo.com，端口为6030（TDengine的默认端口），数据库名为test的连接。这个url中指定用户名（user）为root，密码（password）为taosdata。

 TDengine 的 JDBC URL 规范格式为：
-`jdbc:TAOS://{host_ip}:{port}/[database_name]?[user={user}|&password={password}|&charset={charset}|&cfgdir={config_dir}|&locale={locale}|&timezone={timezone}]`
-
-其中，`{}` 中的内容必须，`[]` 中为可选。配置参数说明如下：
-
+`jdbc:TAOS://[host_name]:[port]/[database_name]?[user={user}|&password={password}|&charset={charset}|&cfgdir={config_dir}|&locale={locale}|&timezone={timezone}]`
+url中的配置参数如下：
 * user：登录 TDengine 用户名，默认值 root。
 * password：用户登录密码，默认值 taosdata。
-* charset：客户端使用的字符集，默认值为系统字符集。
 * cfgdir：客户端配置文件目录路径，Linux OS 上默认值 /etc/taos ，Windows OS 上默认值 C:/TDengine/cfg。
+* charset：客户端使用的字符集，默认值为系统字符集。
 * locale：客户端语言环境，默认值系统当前 locale。
 * timezone：客户端使用的时区，默认值为系统当前时区。

-以上参数可以在 3 处配置，`优先级由高到低`分别如下：
-1. JDBC URL 参数
-    如上所述，可以在 JDBC URL 的参数中指定。
-2. java.sql.DriverManager.getConnection(String jdbcUrl, Properties connProps)
+#### 使用JdbcUrl和Properties获取连接
+
+除了通过指定的jdbcUrl获取连接，还可以使用Properties指定建立连接时的参数，如下所示：
 ```java
 public Connection getConn() throws Exception{
  Class.forName("com.taosdata.jdbc.TSDBDriver");
-  String jdbcUrl = "jdbc:TAOS://127.0.0.1:0/log?user=root&password=taosdata";
+  String jdbcUrl = "jdbc:TAOS://taosdemo.com:6030/test?user=root&password=taosdata";
  Properties connProps = new Properties();
-  connProps.setProperty(TSDBDriver.PROPERTY_KEY_USER, "root");
-  connProps.setProperty(TSDBDriver.PROPERTY_KEY_PASSWORD, "taosdata");
-  connProps.setProperty(TSDBDriver.PROPERTY_KEY_CONFIG_DIR, "/etc/taos");
  connProps.setProperty(TSDBDriver.PROPERTY_KEY_CHARSET, "UTF-8");
  connProps.setProperty(TSDBDriver.PROPERTY_KEY_LOCALE, "en_US.UTF-8");
  connProps.setProperty(TSDBDriver.PROPERTY_KEY_TIME_ZONE, "UTC-8");
@ -111,16 +107,39 @@ public Connection getConn() throws Exception{
  return conn;
 }
 ```
+以上示例，建立一个到hostname为taosdemo.com，端口为6030，数据库名为test的连接。这个连接在url中指定了用户名(user)为root，密码（password）为taosdata，并在connProps中指定了使用的字符集、语言环境、时区等信息。

-3. 客户端配置文件 taos.cfg
+properties中的配置参数如下：
+* TSDBDriver.PROPERTY_KEY_USER：登录 TDengine 用户名，默认值 root。
+* TSDBDriver.PROPERTY_KEY_PASSWORD：用户登录密码，默认值 taosdata。
+* TSDBDriver.PROPERTY_KEY_CONFIG_DIR：客户端配置文件目录路径，Linux OS 上默认值 /etc/taos ，Windows OS 上默认值 C:/TDengine/cfg。
+* TSDBDriver.PROPERTY_KEY_CHARSET：客户端使用的字符集，默认值为系统字符集。
+* TSDBDriver.PROPERTY_KEY_LOCALE：客户端语言环境，默认值系统当前 locale。
+* TSDBDriver.PROPERTY_KEY_TIME_ZONE：客户端使用的时区，默认值为系统当前时区。

-    linux 系统默认配置文件为 /var/lib/taos/taos.cfg，windows 系统默认配置文件路径为 C:\TDengine\cfg\taos.cfg。
-```properties
-# client default username
-# defaultUser           root
+#### 使用客户端配置文件建立连接
+当使用JDBC连接TDengine集群时，可以使用客户端配置文件，在客户端配置文件中指定集群的firstEp、secondEp参数。
+如下所示：
+1. 在java中不指定hostname和port
+```java
+public Connection getConn() throws Exception{
+  Class.forName("com.taosdata.jdbc.TSDBDriver");
+  String jdbcUrl = "jdbc:TAOS://:/test?user=root&password=taosdata";
+  Properties connProps = new Properties();
+  connProps.setProperty(TSDBDriver.PROPERTY_KEY_CHARSET, "UTF-8");
+  connProps.setProperty(TSDBDriver.PROPERTY_KEY_LOCALE, "en_US.UTF-8");
+  connProps.setProperty(TSDBDriver.PROPERTY_KEY_TIME_ZONE, "UTC-8");
+  Connection conn = DriverManager.getConnection(jdbcUrl, connProps);
+  return conn;
+}
+```
+2. 在配置文件中指定firstEp和secondEp
+```
+# first fully qualified domain name (FQDN) for TDengine system
+firstEp               cluster_node1:6030

-# client default password
-# defaultPass           taosdata
+# second fully qualified domain name (FQDN) for TDengine system, for cluster only
+secondEp              cluster_node2:6030

 # default system charset
 # charset               UTF-8
@ -128,6 +147,19 @@ public Connection getConn() throws Exception{
 # system locale
 # locale                en_US.UTF-8
 ```
+
+以上示例，jdbc会使用客户端的配置文件，建立到hostname为cluster_node1，端口为6030，数据库名为test的连接。当集群中firstEp节点失效时，JDBC会尝试使用secondEp连接集群。
+TDengine中，只要保证firstEp和secondEp中一个节点有效，就可以正常建立到集群的连接。
+
+> 注意：这里的配置文件指的是调用JDBC Connector的应用程序所在机器上的配置文件，Linux OS 上默认值 /etc/taos/taos.cfg ，Windows OS 上默认值 C://TDengine/cfg/taos.cfg。
+
+#### 配置参数的优先级
+通过以上3种方式获取连接，如果配置参数在url、Properties、客户端配置文件中有重复，则参数的`优先级由高到低`分别如下：
+1. JDBC URL 参数，如上所述，可以在 JDBC URL 的参数中指定。
+2. Properties connProps
+3. 客户端配置文件 taos.cfg
+例如：在url中指定了password为taosdata，在Properties中指定了password为taosdemo，那么，JDBC会使用url中的password建立连接。
+
 > 更多详细配置请参考[客户端配置][13]

 ### 创建数据库和表
--- a/documentation20/webdocs/markdowndocs/insert-ch.md
+++ b/documentation20/webdocs/markdowndocs/insert-ch.md
@ -22,7 +22,7 @@ INSERT INTO d1001 VALUES (1538548685000, 10.3, 219, 0.31) (1538548695000, 12.6,

 **Tips:** 

- 要提高写入效率，需要批量写入。一批写入的记录条数越多，插入效率就越高。但一条记录不能超过16K，一条SQL语句总长度不能超过64K（可通过参数maxSQLLength配置，最大可配置为8M）。
+- 要提高写入效率，需要批量写入。一批写入的记录条数越多，插入效率就越高。但一条记录不能超过16K，一条SQL语句总长度不能超过64K（可通过参数maxSQLLength配置，最大可配置为1M）。
 - TDengine支持多线程同时写入，要进一步提高写入速度，一个客户端需要打开20个以上的线程同时写。但线程数达到一定数量后，无法再提高，甚至还会下降，因为线程切频繁切换，带来额外开销。
 - 对同一张表，如果新插入记录的时间戳已经存在，新记录将被直接抛弃，也就是说，在一张表里，时间戳必须是唯一的。如果应用自动生成记录，很有可能生成的时间戳是一样的，这样，成功插入的记录条数会小于应用插入的记录条数。
 - 写入的数据的时间戳必须大于当前时间减去配置参数keep的时间。如果keep配置为3650天，那么无法写入比3650天还老的数据。写入数据的时间戳也不能大于当前时间加配置参数days。如果days配置为2，那么无法写入比当前时间还晚2天的数据。
--- a/documentation20/webdocs/markdowndocs/taosd-ch.md
+++ b/documentation20/webdocs/markdowndocs/taosd-ch.md
@ -61,7 +61,7 @@ vnode与其子模块是通过API直接调用，而不是通过消息队列传递

 mnode是整个系统的大脑，负责整个系统的资源调度，负责meta data的管理与存储。

-一个运行的系统里，只有一个mnode，但它有多个副本（由系统配置参数numOfMpeers控制）。这些副本分布在不同的dnode里，目的是保证系统的高可靠运行。副本之间的数据复制是采用同步而非异步的方式，以确保数据的一致性，确保数据不会丢失。这些副本会自动选举一个Master，其他副本是slave。所有数据更新类的操作，都只能在master上进行，而查询类的可以在slave节点上进行。代码实现上，同步模块与vnode共享，但mnode被分配一个特殊的vgroup ID: 1，而且quorum大于1。整个集群系统是由多个dnode组成的，运行的mnode的副本数不可能超过dnode的个数，但不会超过配置的副本数。如果某个mnode副本宕机一段时间，只要超过半数的mnode副本仍在运行，运行的mnode会自动根据整个系统的资源情况，在其他dnode里再启动一个mnode, 以保证运行的副本数。
+一个运行的系统里，只有一个mnode，但它有多个副本（由系统配置参数numOfMnodes控制）。这些副本分布在不同的dnode里，目的是保证系统的高可靠运行。副本之间的数据复制是采用同步而非异步的方式，以确保数据的一致性，确保数据不会丢失。这些副本会自动选举一个Master，其他副本是slave。所有数据更新类的操作，都只能在master上进行，而查询类的可以在slave节点上进行。代码实现上，同步模块与vnode共享，但mnode被分配一个特殊的vgroup ID: 1，而且quorum大于1。整个集群系统是由多个dnode组成的，运行的mnode的副本数不可能超过dnode的个数，但不会超过配置的副本数。如果某个mnode副本宕机一段时间，只要超过半数的mnode副本仍在运行，运行的mnode会自动根据整个系统的资源情况，在其他dnode里再启动一个mnode, 以保证运行的副本数。

 各个dnode通过信息交换，保存有mnode各个副本的End Point列表，并向其中的master节点定时（间隔由系统配置参数statusInterval控制）发送status消息，消息体里包含该dnode的CPU、内存、剩余存储空间、vnode个数，以及各个vnode的状态(存储空间、原始数据大小、记录条数、角色等）。这样mnode就了解整个系统的资源情况，如果用户创建新的表，就可以决定需要在哪个dnode创建；如果增加或删除dnode, 或者监测到某dnode数据过热、或离线太长，就可以决定需要挪动那些vnode，以实现负载均衡。

--- a/packaging/cfg/taos.cfg
+++ b/packaging/cfg/taos.cfg
@ -6,73 +6,76 @@
 ########################################################

 # first fully qualified domain name (FQDN) for TDengine system
-# firstEp               hostname1:6030
-
-# second fully qualified domain name (FQDN) for TDengine system, for cluster only
-# secondEp              cluster_hostname2:6030
+# firstEp                   hostname:6030

 # local fully qualified domain name (FQDN)
-# fqdn                  hostname
+# fqdn                      hostname

 # first port number for the connection (12 continuous UDP/TCP port number are used) 
-# serverPort            6030
+# serverPort                6030

 # log file's directory
-# logDir                /var/log/taos
+# logDir                    /var/log/taos

 # data file's directory
-# dataDir               /var/lib/taos
+# dataDir                   /var/lib/taos

 # the arbitrator's fully qualified domain name (FQDN) for TDengine system, for cluster only   
-# arbitrator            arbitrator_hostname:6042     
+# arbitrator                arbitrator_hostname:6042     

 # number of threads per CPU core
-# numOfThreadsPerCore   1.0
+# numOfThreadsPerCore       1.0
+
+# the proportion of total threads responsible for query
+# ratioOfQueryThreads       0.5

 # number of management nodes in the system
-# numOfMnodes           3
+# numOfMnodes               3

 # enable/disable backuping vnode directory when removing dnode
-# vnodeBak              1
+# vnodeBak                  1
+
+# if report installation / use information
+# telemetryReporting        1

 # enable/disable load balancing
-# balance               1
+# balance                   1

 # role for dnode. 0 - any, 1 - mnode, 2 - dnode
-# role                  0
+# role                      0

 # max timer control blocks
-# maxTmrCtrl            512
+# maxTmrCtrl                512

 # time interval of system monitor, seconds 
-# monitorInterval       30
+# monitorInterval           30

 # number of seconds allowed for a dnode to be offline, for cluster only 
-# offlineThreshold      8640000
+# offlineThreshold          8640000

 # RPC re-try timer, millisecond
-# rpcTimer              300
+# rpcTimer                  300

 # RPC maximum time for ack, seconds. 
-# rpcMaxTime            600
+# rpcMaxTime                600

 # time interval of dnode status reporting to mnode, seconds, for cluster only 
-# statusInterval        1
+# statusInterval            1

 # time interval of heart beat from shell to dnode, seconds
-# shellActivityTimer    3
+# shellActivityTimer        3

 # time of keeping table meta data in cache, seconds
-# tableMetaKeepTimer    7200
+# tableMetaKeepTimer        7200

 # minimum sliding window time, milli-second
-# minSlidingTime        10
+# minSlidingTime            10

 # minimum time window, milli-second
-# minIntervalTime       10
+# minIntervalTime           10

 # maximum delay before launching a stream compution, milli-second
-# maxStreamCompDelay    20000
+# maxStreamCompDelay        20000

 # maximum delay before launching a stream computation for the first time, milli-second
 # maxFirstStreamCompDelay   10000
@ -89,9 +92,6 @@
 # max number of tables per vnode
 # maxTablesPerVnode         1000000

-# step size of increasing table number in a vnode
-# tableIncStepPerVnode      1000
-
 # cache block size (Mbyte)
 # cache                     16

@ -110,6 +110,9 @@
 # maximum rows of records in file block
 # maxRows               4096

+# the number of acknowledgments required for successful data writing
+# quorum                1     
+
 # enable/disable compression
 # comp                  2

@ -122,15 +125,6 @@
 # number of replications, for cluster only 
 # replica               1

-# mqtt hostname  
-# mqttHostName          test.mosquitto.org
-
-# mqtt port  
-# mqttPort              1883
-
-# mqtt topic
-# mqttTopic             /test
-
 # the compressed rpc message, option:
 #  -1 (no compression)
 #   0 (all message compressed),
@ -167,12 +161,12 @@
 # stop writing data when the disk size of the log folder is less than this value
 # minimalDataDirGB      0.1

+# One mnode is equal to the number of vnode consumed
+# mnodeEqualVnodeNum    4
+
 # enbale/disable http service
 # http                  1

-# enable/disable muqq service
-# mqtt                  0
-
 # enable/disable system monitor 
 # monitor               1

@ -189,11 +183,12 @@
 # max number of rows per log filters
 # numOfLogLines         10000000

+# enable/disable async log
+# asyncLog              1
+
 # time of keeping log files, days
 # logKeepDays           0

-# enable/disable async log
-# asyncLog              1

 # The following parameters are used for debug purpose only.
 # debugFlag 8 bits mask: FILE-SCREEN-UNUSED-HeartBeat-DUMP-TRACE_WARN-ERROR
@ -231,18 +226,12 @@
 # debug flag for JNI
 # jniDebugflag          131

-# debug flag for ODBC
-# odbcDebugflag         131
-
 # debug flag for storage
 # uDebugflag            131

 # debug flag for http server
 # httpDebugFlag         131

-# debug flag for mqtt
-# mqttDebugFlag         131
-
 # debug flag for monitor
 # monitorDebugFlag      131

@ -255,6 +244,9 @@
 # debug flag for http server
 # tsdbDebugFlag         131

+# debug flag for continue query
+# cqDebugFlag           131
+
 # enable/disable recording the SQL in taos client
 # tscEnableRecordSql    0

--- a/packaging/docker/Dockerfile
+++ b/packaging/docker/Dockerfile
@ -1,4 +1,4 @@
-FROM centos:7
+FROM ubuntu:20.04

 WORKDIR /root

@ -7,7 +7,7 @@ RUN echo $version
 COPY tdengine.tar.gz /root/
 RUN tar -zxf tdengine.tar.gz
 WORKDIR /root/TDengine-server-$version/
-RUN sh install.sh -e no
+RUN /bin/bash install.sh -e no


 ENV LD_LIBRARY_PATH="$LD_LIBRARY_PATH:/usr/lib"
--- a/packaging/docker/dockerbuild-aarch64.sh
+++ b/packaging/docker/dockerbuild-aarch64.sh
@ -0,0 +1,5 @@
+#!/bin/bash
+set -x
+docker build --rm -f "Dockerfile" -t tdengine/tdengine-aarch64:$1 "." --build-arg version=$1
+docker login -u tdengine -p $2  #replace the docker registry username and password
+docker push tdengine/tdengine-aarch64:$1
--- a/packaging/tools/install.sh
+++ b/packaging/tools/install.sh
@ -272,6 +272,29 @@ function install_config() {
            break
        fi
    done	
+
+    # user email 
+    #EMAIL_PATTERN='^[A-Za-z0-9\u4e00-\u9fa5]+@[a-zA-Z0-9_-]+(\.[a-zA-Z0-9_-]+)+$'
+    #EMAIL_PATTERN='^[\w-]+(\.[\w-]+)*@[\w-]+(\.[\w-]+)+$'
+    #EMAIL_PATTERN="^[\w-]+(\.[\w-]+)*@[\w-]+(\.[\w-]+)+$"
+    echo
+    echo -e -n "${GREEN}Enter your email address for priority support or enter empty to skip${NC}: "
+    read emailAddr
+    while true; do
+        if [ ! -z "$emailAddr" ]; then
+            # check the format of the emailAddr
+            #if [[ "$emailAddr" =~ $EMAIL_PATTERN ]]; then
+                # Write the email address to temp file                    
+                email_file="${install_main_dir}/email" 
+                ${csudo} bash -c "echo $emailAddr > ${email_file}"
+                break         
+            #else
+            #    read -p "Please enter the correct email address: " emailAddr   
+            #fi
+        else
+            break
+        fi
+    done	
 }


--- a/snap/snapcraft.yaml
+++ b/snap/snapcraft.yaml
@ -1,6 +1,6 @@
 name: tdengine
 base: core18
-version: 'RELEASE_VERSION'
+version: '2.0.5.1'
 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.RELEASE_VERSION
+      - usr/lib/libtaos.so.2.0.5.1
      - usr/lib/libtaos.so.1
      - usr/lib/libtaos.so

--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@ -20,4 +20,6 @@ ADD_SUBDIRECTORY(tsdb)
 ADD_SUBDIRECTORY(wal)
 ADD_SUBDIRECTORY(cq)
 ADD_SUBDIRECTORY(dnode)
+ADD_SUBDIRECTORY(connector/odbc)
 ADD_SUBDIRECTORY(connector/jdbc)
+
--- a/src/balance/src/balance.c
+++ b/src/balance/src/balance.c
@ -126,6 +126,8 @@ int32_t balanceAllocVnodes(SVgObj *pVgroup) {

  balanceAccquireDnodeList();

+  mDebug("db:%s, try alloc %d vnodes to vgroup, dnodes total:%d, avail:%d", pVgroup->dbName, pVgroup->numOfVnodes,
+         mnodeGetDnodesNum(), tsBalanceDnodeListSize);
  for (int32_t i = 0; i < pVgroup->numOfVnodes; ++i) {
    for (; dnode < tsBalanceDnodeListSize; ++dnode) {
      SDnodeObj *pDnode = tsBalanceDnodeList[dnode];
@ -135,17 +137,33 @@ int32_t balanceAllocVnodes(SVgObj *pVgroup) {
        pVnodeGid->pDnode = pDnode;
        dnode++;
        vnodes++;
+        mDebug("dnode:%d, is selected, vnodeIndex:%d", pDnode->dnodeId, i);
        break;
+      } else {
+        mDebug("dnode:%d, is not selected, status:%s vnodes:%d disk:%fGB role:%d", pDnode->dnodeId,
+               mnodeGetDnodeStatusStr(pDnode->status), pDnode->openVnodes, pDnode->diskAvailable,
+               pDnode->alternativeRole);
      }
    }
  }

  if (vnodes != pVgroup->numOfVnodes) {
-    mDebug("vgId:%d, db:%s need vnodes:%d, but alloc:%d, free them", pVgroup->vgId, pVgroup->dbName,
-           pVgroup->numOfVnodes, vnodes);
    balanceReleaseDnodeList();
    balanceUnLock();

+    mDebug("db:%s, need vnodes:%d, but alloc:%d", pVgroup->dbName, pVgroup->numOfVnodes, vnodes);
+
+    void *     pIter = NULL;
+    SDnodeObj *pDnode = NULL;
+    while (1) {
+      pIter = mnodeGetNextDnode(pIter, &pDnode);
+      if (pDnode == NULL) break;
+      mDebug("dnode:%d, status:%s vnodes:%d disk:%fGB role:%d", pDnode->dnodeId, mnodeGetDnodeStatusStr(pDnode->status),
+             pDnode->openVnodes, pDnode->diskAvailable, pDnode->alternativeRole);
+      mnodeDecDnodeRef(pDnode);
+    }
+    sdbFreeIter(pIter);
+
    if (mnodeGetOnlineDnodesNum() == 0) {
      return TSDB_CODE_MND_NOT_READY;
    } else {
@ -198,8 +216,8 @@ static bool balanceCheckVgroupReady(SVgObj *pVgroup, SVnodeGid *pRmVnode) {
    SVnodeGid *pVnode = pVgroup->vnodeGid + i;
    if (pVnode == pRmVnode) continue;

-    mTrace("vgId:%d, change vgroup status, dnode:%d status:%d", pVgroup->vgId, pVnode->pDnode->dnodeId,
-           pVnode->pDnode->status);
+    mTrace("vgId:%d, check vgroup status, dnode:%d status:%d, vnode role:%s", pVgroup->vgId, pVnode->pDnode->dnodeId,
+           pVnode->pDnode->status, syncRole[pVnode->role]);
    if (pVnode->pDnode->status == TAOS_DN_STATUS_DROPPING) continue;
    if (pVnode->pDnode->status == TAOS_DN_STATUS_OFFLINE) continue;

@ -553,7 +571,8 @@ static void balanceCheckDnodeAccess() {
      if (pDnode->status != TAOS_DN_STATUS_DROPPING && pDnode->status != TAOS_DN_STATUS_OFFLINE) {
        pDnode->status = TAOS_DN_STATUS_OFFLINE;
        pDnode->offlineReason = TAOS_DN_OFF_STATUS_MSG_TIMEOUT;
-        mInfo("dnode:%d, set to offline state", pDnode->dnodeId);
+        mInfo("dnode:%d, set to offline state, access seq:%d, last seq:%d", pDnode->dnodeId, tsAccessSquence,
+              pDnode->lastAccess);
        balanceSetVgroupOffline(pDnode);
      }
    }
@ -937,6 +956,7 @@ static int32_t balanceRetrieveScores(SShowObj *pShow, char *data, int32_t rows,
    mnodeDecDnodeRef(pDnode);
  }

+  mnodeVacuumResult(data, pShow->numOfColumns, numOfRows, rows, pShow);
  pShow->numOfReads += numOfRows;
  return numOfRows;
 }
@ -957,11 +977,16 @@ static void balanceMonitorDnodeModule() {
      continue;
    }

-    mLInfo("dnode:%d, numOfMnodes:%d expect:%d, add mnode in this dnode", pDnode->dnodeId, numOfMnodes, tsNumOfMnodes);
-    mnodeAddMnode(pDnode->dnodeId);
+    mLInfo("dnode:%d, numOfMnodes:%d expect:%d, create mnode in this dnode", pDnode->dnodeId, numOfMnodes, tsNumOfMnodes);
+    mnodeCreateMnode(pDnode->dnodeId, pDnode->dnodeEp, true);

+#if 0
+    // Only create one mnode each time
+    return;
+#else
    numOfMnodes = mnodeGetMnodesNum();
    if (numOfMnodes >= tsNumOfMnodes) return;
+#endif
  }
 }

--- a/src/client/inc/tscLocalMerge.h
+++ b/src/client/inc/tscLocalMerge.h
@ -72,17 +72,10 @@ typedef struct SLocalReducer {
  bool                   orderPrjOnSTable;   // projection query on stable
 } SLocalReducer;

-typedef struct SSubqueryState {
-  int32_t  numOfRemain;         // the number of remain unfinished subquery
-  int32_t  numOfTotal;          // the number of total sub-queries
-  uint64_t numOfRetrievedRows;  // total number of points in this query
-} SSubqueryState;
-
 typedef struct SRetrieveSupport {
  tExtMemBuffer **  pExtMemBuffer;     // for build loser tree
  tOrderDescriptor *pOrderDescriptor;
  SColumnModel *    pFinalColModel;    // colModel for final result
-  SSubqueryState *  pState;
  int32_t           subqueryIndex;     // index of current vnode in vnode list
  SSqlObj *         pParentSql;
  tFilePage *       localBuffer;       // temp buffer, there is a buffer for each vnode to
--- a/src/client/inc/tscSubquery.h
+++ b/src/client/inc/tscSubquery.h
@ -28,7 +28,7 @@ void tscFetchDatablockFromSubquery(SSqlObj* pSql);
 void tscSetupOutputColumnIndex(SSqlObj* pSql);
 void tscJoinQueryCallback(void* param, TAOS_RES* tres, int code);

-SJoinSupporter* tscCreateJoinSupporter(SSqlObj* pSql, SSubqueryState* pState, int32_t index);
+SJoinSupporter* tscCreateJoinSupporter(SSqlObj* pSql, int32_t index);

 void tscHandleMasterJoinQuery(SSqlObj* pSql);

@ -39,7 +39,7 @@ int32_t tscHandleMultivnodeInsert(SSqlObj *pSql);
 int32_t tscHandleInsertRetry(SSqlObj* pSql);

 void tscBuildResFromSubqueries(SSqlObj *pSql);
-void **doSetResultRowData(SSqlObj *pSql, bool finalResult);
+TAOS_ROW doSetResultRowData(SSqlObj *pSql, bool finalResult);

 #ifdef __cplusplus
 }
--- a/src/client/inc/tscUtil.h
+++ b/src/client/inc/tscUtil.h
@ -66,7 +66,6 @@ typedef struct STidTags {
 #pragma pack(pop)

 typedef struct SJoinSupporter {
-  SSubqueryState* pState;
  SSqlObj*        pObj;           // parent SqlObj
  int32_t         subqueryIndex;  // index of sub query
  SInterval       interval;
@ -110,7 +109,6 @@ SParamInfo* tscAddParamToDataBlock(STableDataBlocks* pDataBlock, char type, uint

 void*   tscDestroyBlockArrayList(SArray* pDataBlockList);
 int32_t tscCopyDataBlockToPayload(SSqlObj* pSql, STableDataBlocks* pDataBlock);
-void    tscFreeUnusedDataBlocks(SArray* pDataBlockList);
 int32_t tscMergeTableDataBlocks(SSqlObj* pSql, SArray* pDataList);
 int32_t tscGetDataBlockFromList(void* pHashList, SArray* pDataBlockList, int64_t id, int32_t size,
                                int32_t startOffset, int32_t rowSize, const char* tableId, STableMeta* pTableMeta,
@ -151,14 +149,13 @@ int tscAllocPayload(SSqlCmd* pCmd, int size);

 TAOS_FIELD tscCreateField(int8_t type, const char* name, int16_t bytes);

-SFieldSupInfo* tscFieldInfoAppend(SFieldInfo* pFieldInfo, TAOS_FIELD* pField);
-SFieldSupInfo* tscFieldInfoInsert(SFieldInfo* pFieldInfo, int32_t index, TAOS_FIELD* field);
+SInternalField* tscFieldInfoAppend(SFieldInfo* pFieldInfo, TAOS_FIELD* pField);
+SInternalField* tscFieldInfoInsert(SFieldInfo* pFieldInfo, int32_t index, TAOS_FIELD* field);

-SFieldSupInfo* tscFieldInfoGetSupp(SFieldInfo* pFieldInfo, int32_t index);
+SInternalField* tscFieldInfoGetInternalField(SFieldInfo* pFieldInfo, int32_t index);
 TAOS_FIELD* tscFieldInfoGetField(SFieldInfo* pFieldInfo, int32_t index);

 void tscFieldInfoUpdateOffset(SQueryInfo* pQueryInfo);
-void tscFieldInfoCopy(SFieldInfo* dst, const SFieldInfo* src);
 void tscFieldInfoUpdateOffsetForInterResult(SQueryInfo* pQueryInfo);

 int16_t tscFieldInfoGetOffset(SQueryInfo* pQueryInfo, int32_t index);
@ -207,8 +204,6 @@ void tscTagCondRelease(STagCond* pCond);

 void tscGetSrcColumnInfo(SSrcColumnInfo* pColInfo, SQueryInfo* pQueryInfo);

-void tscSetFreeHeatBeat(STscObj* pObj);
-bool tscShouldFreeHeartBeat(SSqlObj* pHb);
 bool tscShouldBeFreed(SSqlObj* pSql);

 STableMetaInfo* tscGetTableMetaInfoFromCmd(SSqlCmd *pCmd, int32_t subClauseIndex, int32_t tableIndex);
@ -235,10 +230,11 @@ int  tscGetTableMeta(SSqlObj* pSql, STableMetaInfo* pTableMetaInfo);
 int  tscGetMeterMetaEx(SSqlObj* pSql, STableMetaInfo* pTableMetaInfo, bool createIfNotExists);

 void tscResetForNextRetrieve(SSqlRes* pRes);
-
-void tscAddTimestampColumn(SQueryInfo* pQueryInfo, int16_t functionId, int16_t tableIndex);
 void tscDoQuery(SSqlObj* pSql);

+SVgroupsInfo* tscVgroupInfoClone(SVgroupsInfo *pInfo);
+void* tscVgroupInfoClear(SVgroupsInfo *pInfo);
+void tscSCMVgroupInfoCopy(SCMVgroupInfo* dst, const SCMVgroupInfo* src);
 /**
 * The create object function must be successful expect for the out of memory issue.
 *
--- a/src/client/inc/tsclient.h
+++ b/src/client/inc/tsclient.h
@ -80,6 +80,8 @@ enum {
  DATA_FROM_DATA_FILE = 2,
 };

+typedef void (*__async_cb_func_t)(void *param, TAOS_RES *tres, int32_t numOfRows);
+
 typedef struct STableComInfo {
  uint8_t numOfTags;
  uint8_t precision;
@ -88,10 +90,10 @@ typedef struct STableComInfo {
 } STableComInfo;

 typedef struct SCMCorVgroupInfo {
-  int32_t version;
-  int8_t  inUse;
-  int8_t  numOfEps;
-  SEpAddr epAddr[TSDB_MAX_REPLICA];
+  int32_t    version;
+  int8_t     inUse;
+  int8_t     numOfEps;
+  SEpAddr1   epAddr[TSDB_MAX_REPLICA];
 } SCMCorVgroupInfo;

 typedef struct STableMeta {
@ -140,16 +142,17 @@ typedef struct SColumnIndex {
  int16_t columnIndex;
 } SColumnIndex;

-typedef struct SFieldSupInfo {
+typedef struct SInternalField {
+  TAOS_FIELD      field;
  bool            visible;
  SExprInfo      *pArithExprInfo;
  SSqlExpr       *pSqlExpr;
-} SFieldSupInfo;
+} SInternalField;

 typedef struct SFieldInfo {
-  int16_t numOfOutput;   // number of column in result
-  SArray *pFields;       // SArray<TAOS_FIELD>
-  SArray *pSupportInfo;  // SArray<SFieldSupInfo>
+  int16_t      numOfOutput;   // number of column in result
+  TAOS_FIELD*  final;
+  SArray      *internalField; // SArray<SInternalField>
 } SFieldInfo;

 typedef struct SColumn {
@ -226,7 +229,7 @@ typedef struct STableDataBlocks {
 typedef struct SQueryInfo {
  int16_t          command;       // the command may be different for each subclause, so keep it seperately.
  uint32_t         type;          // query/insert type
-  // TODO refactor
+
  STimeWindow      window;        // query time window
  SInterval        interval;

@ -306,7 +309,7 @@ typedef struct {
  int32_t               numOfGroups;
  SResRec *             pGroupRec;
  char *                data;
-  void **               tsrow;
+  TAOS_ROW              tsrow;
  int32_t*              length;  // length for each field for current row
  char **               buffer;  // Buffer used to put multibytes encoded using unicode (wchar_t)
  SColumnIndex *        pColumnIndex;
@ -334,6 +337,12 @@ typedef struct STscObj {
  T_REF_DECLARE()
 } STscObj;

+typedef struct SSubqueryState {
+  int32_t          numOfRemain;         // the number of remain unfinished subquery
+  int32_t          numOfSub;            // the number of total sub-queries
+  uint64_t         numOfRetrievedRows;  // total number of points in this query
+} SSubqueryState;
+
 typedef struct SSqlObj {
  void            *signature;
  pthread_t        owner;        // owner of sql object, by which it is executed
@ -355,10 +364,11 @@ typedef struct SSqlObj {
  tsem_t           rspSem;
  SSqlCmd          cmd;
  SSqlRes          res;
-  uint16_t         numOfSubs;
-  struct SSqlObj **pSubs;
-  struct SSqlObj * prev, *next;

+  SSubqueryState   subState;
+  struct SSqlObj **pSubs;
+
+  struct SSqlObj  *prev, *next;
  struct SSqlObj **self;
 } SSqlObj;

@ -433,19 +443,20 @@ void tscPartiallyFreeSqlObj(SSqlObj *pSql);
 * @param pObj
 */
 void tscFreeSqlObj(SSqlObj *pSql);
-
-void tscFreeSqlObjInCache(void *pSql);
+void tscFreeRegisteredSqlObj(void *pSql);
+void tscFreeTableMetaHelper(void *pTableMeta);

 void tscCloseTscObj(STscObj *pObj);

+// todo move to taos? or create a new file: taos_internal.h
 TAOS *taos_connect_a(char *ip, char *user, char *pass, char *db, uint16_t port, void (*fp)(void *, TAOS_RES *, int),
-                     void *param, void **taos);
-void waitForQueryRsp(void *param, TAOS_RES *tres, int code) ;
+                     void *param, TAOS **taos);
+TAOS_RES* taos_query_h(TAOS* taos, const char *sqlstr, TAOS_RES** res);
+void waitForQueryRsp(void *param, TAOS_RES *tres, int code);

-void doAsyncQuery(STscObj *pObj, SSqlObj *pSql, void (*fp)(), void *param, const char *sqlstr, size_t sqlLen);
+void doAsyncQuery(STscObj *pObj, SSqlObj *pSql, __async_cb_func_t fp, void *param, const char *sqlstr, size_t sqlLen);

 void tscProcessMultiVnodesImportFromFile(SSqlObj *pSql);
-void tscKillSTableQuery(SSqlObj *pSql);
 void tscInitResObjForLocalQuery(SSqlObj *pObj, int32_t numOfRes, int32_t rowLen);
 bool tscIsUpdateQuery(SSqlObj* pSql);
 bool tscHasReachLimitation(SQueryInfo *pQueryInfo, SSqlRes *pRes);
@ -458,7 +469,7 @@ int32_t tscSQLSyntaxErrMsg(char* msg, const char* additionalInfo,  const char* s
 int32_t tscToSQLCmd(SSqlObj *pSql, struct SSqlInfo *pInfo);

 static FORCE_INLINE void tscGetResultColumnChr(SSqlRes* pRes, SFieldInfo* pFieldInfo, int32_t columnIndex) {
-  SFieldSupInfo* pInfo = (SFieldSupInfo*) TARRAY_GET_ELEM(pFieldInfo->pSupportInfo, columnIndex);
+  SInternalField* pInfo = (SInternalField*) TARRAY_GET_ELEM(pFieldInfo->internalField, columnIndex);
  assert(pInfo->pSqlExpr != NULL);

  int32_t type = pInfo->pSqlExpr->resType;
@ -471,11 +482,11 @@ static FORCE_INLINE void tscGetResultColumnChr(SSqlRes* pRes, SFieldInfo* pField
    if (type == TSDB_DATA_TYPE_NCHAR || type == TSDB_DATA_TYPE_BINARY) {
      pData = pInfo->pSqlExpr->param[1].pz;
      pRes->length[columnIndex] = pInfo->pSqlExpr->param[1].nLen;
-      pRes->tsrow[columnIndex] = (pInfo->pSqlExpr->param[1].nType == TSDB_DATA_TYPE_NULL) ? NULL : pData;
+      pRes->tsrow[columnIndex] = (pInfo->pSqlExpr->param[1].nType == TSDB_DATA_TYPE_NULL) ? NULL : (unsigned char*)pData;
    } else {
      assert(bytes == tDataTypeDesc[type].nSize);

-      pRes->tsrow[columnIndex] = isNull(pData, type) ? NULL : &pInfo->pSqlExpr->param[1].i64Key;
+      pRes->tsrow[columnIndex] = isNull(pData, type) ? NULL : (unsigned char*)&pInfo->pSqlExpr->param[1].i64Key;
      pRes->length[columnIndex] = bytes;
    }
  } else {
@ -483,7 +494,7 @@ static FORCE_INLINE void tscGetResultColumnChr(SSqlRes* pRes, SFieldInfo* pField
      int32_t realLen = varDataLen(pData);
      assert(realLen <= bytes - VARSTR_HEADER_SIZE);

-      pRes->tsrow[columnIndex] = (isNull(pData, type)) ? NULL : ((tstr *)pData)->data;
+      pRes->tsrow[columnIndex] = (isNull(pData, type)) ? NULL : (unsigned char*)((tstr *)pData)->data;
      if (realLen < pInfo->pSqlExpr->resBytes - VARSTR_HEADER_SIZE) {  // todo refactor
        *(pData + realLen + VARSTR_HEADER_SIZE) = 0;
      }
@ -492,7 +503,7 @@ static FORCE_INLINE void tscGetResultColumnChr(SSqlRes* pRes, SFieldInfo* pField
    } else {
      assert(bytes == tDataTypeDesc[type].nSize);

-      pRes->tsrow[columnIndex] = isNull(pData, type) ? NULL : pData;
+      pRes->tsrow[columnIndex] = isNull(pData, type) ? NULL : (unsigned char*)pData;
      pRes->length[columnIndex] = bytes;
    }
  }
@ -510,8 +521,6 @@ extern SRpcCorEpSet tscMgmtEpSet;

 extern int (*tscBuildMsg[TSDB_SQL_MAX])(SSqlObj *pSql, SSqlInfo *pInfo);

-typedef void (*__async_cb_func_t)(void *param, TAOS_RES *tres, int numOfRows);
-
 int32_t tscCompareTidTags(const void* p1, const void* p2);
 void tscBuildVgroupTableInfo(SSqlObj* pSql, STableMetaInfo* pTableMetaInfo, SArray* tables);

--- a/src/client/src/tscAsync.c
+++ b/src/client/src/tscAsync.c
@ -40,7 +40,7 @@ static void tscProcessAsyncRetrieveImpl(void *param, TAOS_RES *tres, int numOfRo
 static void tscAsyncFetchRowsProxy(void *param, TAOS_RES *tres, int numOfRows);
 static void tscAsyncFetchSingleRowProxy(void *param, TAOS_RES *tres, int numOfRows);

-void doAsyncQuery(STscObj* pObj, SSqlObj* pSql, void (*fp)(), void* param, const char* sqlstr, size_t sqlLen) {
+void doAsyncQuery(STscObj* pObj, SSqlObj* pSql, __async_cb_func_t fp, void* param, const char* sqlstr, size_t sqlLen) {
  SSqlCmd* pCmd = &pSql->cmd;

  pSql->signature = pSql;
@ -327,7 +327,7 @@ void tscAsyncFetchSingleRowProxy(void *param, TAOS_RES *tres, int numOfRows) {
  }
  
  for (int i = 0; i < pCmd->numOfCols; ++i){
-    SFieldSupInfo* pSup = taosArrayGet(pQueryInfo->fieldsInfo.pSupportInfo, i);
+    SInternalField* pSup = taosArrayGet(pQueryInfo->fieldsInfo.internalField, i);
    if (pSup->pSqlExpr != NULL) {
 //      pRes->tsrow[i] = TSC_GET_RESPTR_BASE(pRes, pQueryInfo, i) + pSup->pSqlExpr->resBytes * pRes->row;
    } else {
@ -348,7 +348,7 @@ void tscProcessFetchRow(SSchedMsg *pMsg) {
  SQueryInfo *pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);

  for (int i = 0; i < pCmd->numOfCols; ++i) {
-    SFieldSupInfo* pSup = taosArrayGet(pQueryInfo->fieldsInfo.pSupportInfo, i);
+    SInternalField* pSup = taosArrayGet(pQueryInfo->fieldsInfo.internalField, i);

    if (pSup->pSqlExpr != NULL) {
      tscGetResultColumnChr(pRes, &pQueryInfo->fieldsInfo, i);
@ -361,15 +361,6 @@ void tscProcessFetchRow(SSchedMsg *pMsg) {
  (*pSql->fetchFp)(pSql->param, pSql, pRes->tsrow);
 }

-void tscProcessAsyncRes(SSchedMsg *pMsg) {
-  SSqlObj *pSql = (SSqlObj *)pMsg->ahandle;
-  SSqlRes *pRes = &pSql->res;
-  assert(pSql->fp != NULL && pSql->fetchFp != NULL);
-
-  pSql->fp = pSql->fetchFp;
-  (*pSql->fp)(pSql->param, pSql, pRes->code);
-}
-
 // this function will be executed by queue task threads, so the terrno is not valid
 static void tscProcessAsyncError(SSchedMsg *pMsg) {
  void (*fp)() = pMsg->ahandle;
@ -393,22 +384,15 @@ void tscQueueAsyncRes(SSqlObj *pSql) {
  if (pSql == NULL || pSql->signature != pSql) {
    tscDebug("%p SqlObj is freed, not add into queue async res", pSql);
    return;
-  } else {
-    tscError("%p add into queued async res, code:%s", pSql, tstrerror(pSql->res.code));
  }

-  SSchedMsg schedMsg = { 0 };
-  schedMsg.fp = tscProcessAsyncRes;
-  schedMsg.ahandle = pSql;
-  schedMsg.thandle = (void *)1;
-  schedMsg.msg = NULL;
-  taosScheduleTask(tscQhandle, &schedMsg);
-}
+  tscError("%p add into queued async res, code:%s", pSql, tstrerror(pSql->res.code));

-void tscProcessAsyncFree(SSchedMsg *pMsg) {
-  SSqlObj *pSql = (SSqlObj *)pMsg->ahandle;
-  tscDebug("%p sql is freed", pSql);
-  taos_free_result(pSql);
+  SSqlRes *pRes = &pSql->res;
+  assert(pSql->fp != NULL && pSql->fetchFp != NULL);
+
+  pSql->fp = pSql->fetchFp;
+  (*pSql->fp)(pSql->param, pSql, pRes->code);
 }

 int tscSendMsgToServer(SSqlObj *pSql);
@ -421,11 +405,11 @@ void tscTableMetaCallBack(void *param, TAOS_RES *res, int code) {
  SSqlRes *pRes = &pSql->res;
  pRes->code = code;

+  const char* msg = (pCmd->command == TSDB_SQL_STABLEVGROUP)? "vgroup-list":"table-meta";
  if (code != TSDB_CODE_SUCCESS) {
-    tscError("%p get tableMeta failed, code:%s", pSql, tstrerror(code));
+    tscError("%p get %s failed, code:%s", pSql, msg, tstrerror(code));
    goto _error;
  } else {
-    const char* msg = (pCmd->command == TSDB_SQL_STABLEVGROUP)? "vgroup-list":"table-meta";
    tscDebug("%p get %s successfully", pSql, msg);
  }

--- a/src/client/src/tscFunctionImpl.c
+++ b/src/client/src/tscFunctionImpl.c
@ -2445,8 +2445,8 @@ static bool percentile_function_setup(SQLFunctionCtx *pCtx) {
  // in the first round, get the min-max value of all involved data
  SResultInfo *pResInfo = GET_RES_INFO(pCtx);
  SPercentileInfo *pInfo = pResInfo->interResultBuf;
-  pInfo->minval = DBL_MAX;
-  pInfo->maxval = -DBL_MAX;
+  SET_DOUBLE_VAL(&pInfo->minval, DBL_MAX);
+  SET_DOUBLE_VAL(&pInfo->maxval, -DBL_MAX);
  pInfo->numOfElems = 0;

  return true;
@ -2461,12 +2461,12 @@ static void percentile_function(SQLFunctionCtx *pCtx) {
  // the first stage, only acquire the min/max value
  if (pInfo->stage == 0) {
    if (pCtx->preAggVals.isSet) {
-      if (pInfo->minval > pCtx->preAggVals.statis.min) {
-        pInfo->minval = (double)pCtx->preAggVals.statis.min;
+      if (GET_DOUBLE_VAL(&pInfo->minval) > pCtx->preAggVals.statis.min) {
+        SET_DOUBLE_VAL(&pInfo->minval, (double)pCtx->preAggVals.statis.min);
      }

-      if (pInfo->maxval < pCtx->preAggVals.statis.max) {
-        pInfo->maxval = (double)pCtx->preAggVals.statis.max;
+      if (GET_DOUBLE_VAL(&pInfo->maxval) < pCtx->preAggVals.statis.max) {
+        SET_DOUBLE_VAL(&pInfo->maxval, (double)pCtx->preAggVals.statis.max);
      }

      pInfo->numOfElems += (pCtx->size - pCtx->preAggVals.statis.numOfNull);
@ -2500,12 +2500,12 @@ static void percentile_function(SQLFunctionCtx *pCtx) {
            break;
        }

-        if (v < pInfo->minval) {
-          pInfo->minval = v;
+        if (v < GET_DOUBLE_VAL(&pInfo->minval)) {
+          SET_DOUBLE_VAL(&pInfo->minval, v);
        }

-        if (v > pInfo->maxval) {
-          pInfo->maxval = v;
+        if (v > GET_DOUBLE_VAL(&pInfo->maxval)) {
+          SET_DOUBLE_VAL(&pInfo->maxval, v);
        }

        pInfo->numOfElems += 1;
@ -2564,12 +2564,12 @@ static void percentile_function_f(SQLFunctionCtx *pCtx, int32_t index) {
        break;
    }

-    if (v < pInfo->minval) {
-      pInfo->minval = v;
+    if (v < GET_DOUBLE_VAL(&pInfo->minval)) {
+      SET_DOUBLE_VAL(&pInfo->minval, v);
    }

-    if (v > pInfo->maxval) {
-      pInfo->maxval = v;
+    if (v > GET_DOUBLE_VAL(&pInfo->maxval)) {
+      SET_DOUBLE_VAL(&pInfo->maxval, v);
    }

    pInfo->numOfElems += 1;
@ -2609,7 +2609,7 @@ static void percentile_next_step(SQLFunctionCtx *pCtx) {
    }

    pInfo->stage += 1;
-    pInfo->pMemBucket = tMemBucketCreate(pCtx->inputBytes, pCtx->inputType, pInfo->minval, pInfo->maxval);
+    pInfo->pMemBucket = tMemBucketCreate(pCtx->inputBytes, pCtx->inputType, GET_DOUBLE_VAL(&pInfo->minval), GET_DOUBLE_VAL(&pInfo->maxval));
  } else {
    pResInfo->complete = true;
  }
--- a/src/client/src/tscLocal.c
+++ b/src/client/src/tscLocal.c
@ -239,7 +239,7 @@ static int32_t tscBuildTableSchemaResultFields(SSqlObj *pSql, int32_t numOfCols,
  TAOS_FIELD f = {.type = TSDB_DATA_TYPE_BINARY, .bytes = (TSDB_COL_NAME_LEN - 1) + VARSTR_HEADER_SIZE};
  tstrncpy(f.name, "Field", sizeof(f.name));
  
-  SFieldSupInfo* pInfo = tscFieldInfoAppend(&pQueryInfo->fieldsInfo, &f);
+  SInternalField* pInfo = tscFieldInfoAppend(&pQueryInfo->fieldsInfo, &f);
  pInfo->pSqlExpr = tscSqlExprAppend(pQueryInfo, TSDB_FUNC_TS_DUMMY, &index, TSDB_DATA_TYPE_BINARY,
      (TSDB_COL_NAME_LEN - 1) + VARSTR_HEADER_SIZE, (TSDB_COL_NAME_LEN - 1), false);
  
@ -296,7 +296,7 @@ static int32_t tscProcessDescribeTable(SSqlObj *pSql) {
  return tscSetValueToResObj(pSql, rowLen);
 }
 static int32_t tscGetNthFieldResult(TAOS_ROW row, TAOS_FIELD* fields, int *lengths, int idx, char *result) {
-  const char *val = row[idx];
+  const char *val = (const char*)row[idx];
  if (val == NULL) {
    sprintf(result, "%s", TSDB_DATA_NULL_STR);
    return -1;
@ -485,7 +485,7 @@ static int32_t tscSCreateBuildResultFields(SSqlObj *pSql, BuildType type, const
    tstrncpy(f.name, "Database", sizeof(f.name));
  } 

-  SFieldSupInfo* pInfo = tscFieldInfoAppend(&pQueryInfo->fieldsInfo, &f);
+  SInternalField* pInfo = tscFieldInfoAppend(&pQueryInfo->fieldsInfo, &f);
  pInfo->pSqlExpr = tscSqlExprAppend(pQueryInfo, TSDB_FUNC_TS_DUMMY, &index, TSDB_DATA_TYPE_BINARY,
      f.bytes, f.bytes - VARSTR_HEADER_SIZE, false);

@ -922,19 +922,17 @@ void tscSetLocalQueryResult(SSqlObj *pSql, const char *val, const char *columnNa
  pQueryInfo->order.order = TSDB_ORDER_ASC;

  tscFieldInfoClear(&pQueryInfo->fieldsInfo);
-  pQueryInfo->fieldsInfo.pFields = taosArrayInit(1, sizeof(TAOS_FIELD));
-  pQueryInfo->fieldsInfo.pSupportInfo = taosArrayInit(1, sizeof(SFieldSupInfo));
+  pQueryInfo->fieldsInfo.internalField = taosArrayInit(1, sizeof(SInternalField));

  TAOS_FIELD f = tscCreateField((int8_t)type, columnName, (int16_t)valueLength);
  tscFieldInfoAppend(&pQueryInfo->fieldsInfo, &f);

  tscInitResObjForLocalQuery(pSql, 1, (int32_t)valueLength);

-  TAOS_FIELD *pField = tscFieldInfoGetField(&pQueryInfo->fieldsInfo, 0);
-  SFieldSupInfo* pInfo = tscFieldInfoGetSupp(&pQueryInfo->fieldsInfo, 0);
+  SInternalField* pInfo = tscFieldInfoGetInternalField(&pQueryInfo->fieldsInfo, 0);
  pInfo->pSqlExpr = taosArrayGetP(pQueryInfo->exprList, 0);

-  memcpy(pRes->data, val, pField->bytes);
+  memcpy(pRes->data, val, pInfo->field.bytes);
 }

 int tscProcessLocalCmd(SSqlObj *pSql) {
--- a/src/client/src/tscLocalMerge.c
+++ b/src/client/src/tscLocalMerge.c
@ -510,7 +510,8 @@ void tscDestroyLocalReducer(SSqlObj *pSql) {
    taosTFree(pLocalReducer->pResultBuf);

    if (pLocalReducer->pResInfo != NULL) {
-      for (int32_t i = 0; i < pQueryInfo->fieldsInfo.numOfOutput; ++i) {
+      size_t num = tscSqlExprNumOfExprs(pQueryInfo);
+      for (int32_t i = 0; i < num; ++i) {
        taosTFree(pLocalReducer->pResInfo[i].interResultBuf);
      }

@ -554,27 +555,48 @@ static int32_t createOrderDescriptor(tOrderDescriptor **pOrderDesc, SSqlCmd *pCm
    numOfGroupByCols++;
  }

-  int32_t *orderIdx = (int32_t *)calloc(numOfGroupByCols, sizeof(int32_t));
-  if (orderIdx == NULL) {
+  int32_t *orderColIndexList = (int32_t *)calloc(numOfGroupByCols, sizeof(int32_t));
+  if (orderColIndexList == NULL) {
    return TSDB_CODE_TSC_OUT_OF_MEMORY;
  }

  if (numOfGroupByCols > 0) {
-    int32_t startCols = pQueryInfo->fieldsInfo.numOfOutput - pQueryInfo->groupbyExpr.numOfGroupCols;

-    // tags value locate at the last columns
-    for (int32_t i = 0; i < pQueryInfo->groupbyExpr.numOfGroupCols; ++i) {
-      orderIdx[i] = startCols++;
-    }
+    if (pQueryInfo->groupbyExpr.numOfGroupCols > 0) {
+      int32_t startCols = pQueryInfo->fieldsInfo.numOfOutput - pQueryInfo->groupbyExpr.numOfGroupCols;

-    if (pQueryInfo->interval.interval != 0) {
-      // the first column is the timestamp, handles queries like "interval(10m) group by tags"
-      orderIdx[numOfGroupByCols - 1] = PRIMARYKEY_TIMESTAMP_COL_INDEX;
+      // the last "pQueryInfo->groupbyExpr.numOfGroupCols" columns are order-by columns
+      for (int32_t i = 0; i < pQueryInfo->groupbyExpr.numOfGroupCols; ++i) {
+        orderColIndexList[i] = startCols++;
+      }
+
+      if (pQueryInfo->interval.interval != 0) {
+        // the first column is the timestamp, handles queries like "interval(10m) group by tags"
+        orderColIndexList[numOfGroupByCols - 1] = PRIMARYKEY_TIMESTAMP_COL_INDEX; //TODO ???
+      }
+    } else {
+      /*
+       * 1. the orderby ts asc/desc projection query for the super table
+       * 2. interval query without groupby clause
+       */
+      if (pQueryInfo->interval.interval != 0) {
+        orderColIndexList[0] = PRIMARYKEY_TIMESTAMP_COL_INDEX;
+      } else {
+        size_t size = tscSqlExprNumOfExprs(pQueryInfo);
+        for (int32_t i = 0; i < size; ++i) {
+          SSqlExpr *pExpr = tscSqlExprGet(pQueryInfo, i);
+          if (pExpr->functionId == TSDB_FUNC_PRJ && pExpr->colInfo.colId == PRIMARYKEY_TIMESTAMP_COL_INDEX) {
+            orderColIndexList[0] = i;
+          }
+        }
+      }
+
+      assert(pQueryInfo->order.orderColId == PRIMARYKEY_TIMESTAMP_COL_INDEX);
    }
  }

-  *pOrderDesc = tOrderDesCreate(orderIdx, numOfGroupByCols, pModel, pQueryInfo->order.order);
-  taosTFree(orderIdx);
+  *pOrderDesc = tOrderDesCreate(orderColIndexList, numOfGroupByCols, pModel, pQueryInfo->order.order);
+  taosTFree(orderColIndexList);

  if (*pOrderDesc == NULL) {
    return TSDB_CODE_TSC_OUT_OF_MEMORY;
@ -588,7 +610,6 @@ bool isSameGroup(SSqlCmd *pCmd, SLocalReducer *pReducer, char *pPrev, tFilePage

  // disable merge procedure for column projection query
  int16_t functionId = pReducer->pCtx[0].functionId;
-  assert(functionId != TSDB_FUNC_ARITHM);
  if (pReducer->orderPrjOnSTable) {
    return true;
  }
@ -606,7 +627,7 @@ bool isSameGroup(SSqlCmd *pCmd, SLocalReducer *pReducer, char *pPrev, tFilePage
    return true;
  }

-  if (orderInfo->pData[numOfCols - 1] == PRIMARYKEY_TIMESTAMP_COL_INDEX) {
+  if (orderInfo->colIndex[numOfCols - 1] == PRIMARYKEY_TIMESTAMP_COL_INDEX) {
    /*
     * super table interval query
     * if the order columns is the primary timestamp, all result data belongs to one group
@ -620,7 +641,7 @@ bool isSameGroup(SSqlCmd *pCmd, SLocalReducer *pReducer, char *pPrev, tFilePage
  }

  // only one row exists
-  int32_t index = orderInfo->pData[0];
+  int32_t index = orderInfo->colIndex[0];
  int32_t offset = (pOrderDesc->pColumnModel)->pFields[index].offset;

  int32_t ret = memcmp(pPrev + offset, tmpBuffer->data + offset, pOrderDesc->pColumnModel->rowSize - offset);
@ -639,7 +660,7 @@ int32_t tscLocalReducerEnvCreate(SSqlObj *pSql, tExtMemBuffer ***pMemBuffer, tOr
  SQueryInfo *    pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);
  STableMetaInfo *pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);

-  (*pMemBuffer) = (tExtMemBuffer **)malloc(POINTER_BYTES * pSql->numOfSubs);
+  (*pMemBuffer) = (tExtMemBuffer **)malloc(POINTER_BYTES * pSql->subState.numOfSub);
  if (*pMemBuffer == NULL) {
    tscError("%p failed to allocate memory", pSql);
    pRes->code = TSDB_CODE_TSC_OUT_OF_MEMORY;
@ -661,7 +682,6 @@ int32_t tscLocalReducerEnvCreate(SSqlObj *pSql, tExtMemBuffer ***pMemBuffer, tOr

    pSchema[i].bytes = pExpr->resBytes;
    pSchema[i].type = (int8_t)pExpr->resType;
-
    rlen += pExpr->resBytes;
  }

@ -701,12 +721,8 @@ int32_t tscLocalReducerEnvCreate(SSqlObj *pSql, tExtMemBuffer ***pMemBuffer, tOr
    int16_t type = -1;
    int16_t bytes = 0;

-    //    if ((pExpr->functionId >= TSDB_FUNC_FIRST_DST && pExpr->functionId <= TSDB_FUNC_LAST_DST) ||
-    //        (pExpr->functionId >= TSDB_FUNC_SUM && pExpr->functionId <= TSDB_FUNC_MAX) ||
-    //        pExpr->functionId == TSDB_FUNC_LAST_ROW) {
    // the final result size and type in the same as query on single table.
    // so here, set the flag to be false;
-
    int32_t functionId = pExpr->functionId;
    if (functionId >= TSDB_FUNC_TS && functionId <= TSDB_FUNC_DIFF) {
      type = pModel->pFields[i].field.type;
@ -742,6 +758,7 @@ void tscLocalReducerEnvDestroy(tExtMemBuffer **pMemBuffer, tOrderDescriptor *pDe
                               int32_t numOfVnodes) {
  destroyColumnModel(pFinalModel);
  tOrderDescDestroy(pDesc);
+
  for (int32_t i = 0; i < numOfVnodes; ++i) {
    pMemBuffer[i] = destoryExtMemBuffer(pMemBuffer[i]);
  }
--- a/src/client/src/tscPrepare.c
+++ b/src/client/src/tscPrepare.c
@ -266,6 +266,388 @@ static int doBindParam(char* data, SParamInfo* param, TAOS_BIND* bind) {
    return TSDB_CODE_SUCCESS;
  }

+  if (1) {
+    // allow user bind param data with different type
+    short size = 0;
+    union {
+      int8_t          v1;
+      int16_t         v2;
+      int32_t         v4;
+      int64_t         v8;
+      float           f4;
+      double          f8;
+      unsigned char   buf[32*1024];
+    } u;
+    switch (param->type) {
+      case TSDB_DATA_TYPE_BOOL: {
+        switch (bind->buffer_type) {
+          case TSDB_DATA_TYPE_BOOL: {
+            u.v1 = *(int8_t*)bind->buffer;
+            if (u.v1==0 || u.v1==1) break;
+          } break;
+          case TSDB_DATA_TYPE_TINYINT: {
+            u.v1 = *(int8_t*)bind->buffer;
+            if (u.v1==0 || u.v1==1) break;
+          } break;
+          case TSDB_DATA_TYPE_SMALLINT: {
+            u.v1 = (int8_t)*(int16_t*)bind->buffer;
+            if (u.v1==0 || u.v1==1) break;
+          } break;
+          case TSDB_DATA_TYPE_INT: {
+            u.v1 = (int8_t)*(int32_t*)bind->buffer;
+            if (u.v1==0 || u.v1==1) break;
+          } break;
+          case TSDB_DATA_TYPE_BIGINT: {
+            u.v1 = (int8_t)*(int64_t*)bind->buffer;
+            if (u.v1==0 || u.v1==1) break;
+          } break;
+          case TSDB_DATA_TYPE_BINARY:
+          case TSDB_DATA_TYPE_NCHAR: {
+            // "0", "1" convertible
+            if (strncmp((const char*)bind->buffer, "0", *bind->length)==0) {
+              u.v1 = 0;
+              break;
+            }
+            if (strncmp((const char*)bind->buffer, "1", *bind->length)==0) {
+              u.v1 = 1;
+              break;
+            }
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+          case TSDB_DATA_TYPE_FLOAT:
+          case TSDB_DATA_TYPE_DOUBLE:
+          case TSDB_DATA_TYPE_TIMESTAMP:
+          default: {
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+        }
+        memcpy(data + param->offset, &u.v1, sizeof(u.v1));
+        return TSDB_CODE_SUCCESS;
+      } break;
+      case TSDB_DATA_TYPE_TINYINT: {
+        switch (bind->buffer_type) {
+          case TSDB_DATA_TYPE_BOOL:
+          case TSDB_DATA_TYPE_TINYINT: {
+            int8_t v = *(int8_t*)bind->buffer;
+            u.v1 = v;
+            if (v >= SCHAR_MIN && v <= SCHAR_MAX) break;
+          } break;
+          case TSDB_DATA_TYPE_SMALLINT: {
+            int16_t v = *(int16_t*)bind->buffer;
+            u.v1 = (int8_t)v;
+            if (v >= SCHAR_MIN && v <= SCHAR_MAX) break;
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+          case TSDB_DATA_TYPE_INT: {
+            int32_t v = *(int32_t*)bind->buffer;
+            u.v1 = (int8_t)v;
+            if (v >= SCHAR_MIN && v <= SCHAR_MAX) break;
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+          case TSDB_DATA_TYPE_BIGINT: {
+            int64_t v = *(int64_t*)bind->buffer;
+            u.v1 = (int8_t)v;
+            if (v >= SCHAR_MIN && v <= SCHAR_MAX) break;
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+          case TSDB_DATA_TYPE_BINARY:
+          case TSDB_DATA_TYPE_NCHAR: {
+            int64_t v;
+            int n,r;
+            r = sscanf((const char*)bind->buffer, "%" PRId64 "%n", &v, &n);
+            if (r==1 && n==strlen((const char*)bind->buffer)) {
+              u.v1 = (int8_t)v;
+              if (v >= SCHAR_MIN && v <= SCHAR_MAX) break;
+            }
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+          case TSDB_DATA_TYPE_FLOAT:
+          case TSDB_DATA_TYPE_DOUBLE:
+          case TSDB_DATA_TYPE_TIMESTAMP:
+          default: {
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+        }
+        memcpy(data + param->offset, &u.v1, sizeof(u.v1));
+        return TSDB_CODE_SUCCESS;
+			} break;
+      case TSDB_DATA_TYPE_SMALLINT: {
+        switch (bind->buffer_type) {
+          case TSDB_DATA_TYPE_BOOL:
+          case TSDB_DATA_TYPE_TINYINT:
+          case TSDB_DATA_TYPE_SMALLINT: {
+            int v = *(int16_t*)bind->buffer;
+            u.v2 = (int16_t)v;
+          } break;
+          case TSDB_DATA_TYPE_INT: {
+            int32_t v = *(int32_t*)bind->buffer;
+            u.v2 = (int16_t)v;
+            if (v >= SHRT_MIN && v <= SHRT_MAX) break;
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+          case TSDB_DATA_TYPE_BIGINT: {
+            int64_t v = *(int64_t*)bind->buffer;
+            u.v2 = (int16_t)v;
+            if (v >= SHRT_MIN && v <= SHRT_MAX) break;
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+          case TSDB_DATA_TYPE_BINARY:
+          case TSDB_DATA_TYPE_NCHAR: {
+            int64_t v;
+            int n,r;
+            r = sscanf((const char*)bind->buffer, "%" PRId64 "%n", &v, &n);
+            if (r==1 && n==strlen((const char*)bind->buffer)) {
+              u.v2 = (int16_t)v;
+              if (v >= SHRT_MIN && v <= SHRT_MAX) break;
+            }
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+          case TSDB_DATA_TYPE_FLOAT:
+          case TSDB_DATA_TYPE_DOUBLE:
+          case TSDB_DATA_TYPE_TIMESTAMP:
+          default: {
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+        }
+        memcpy(data + param->offset, &u.v2, sizeof(u.v2));
+        return TSDB_CODE_SUCCESS;
+			} break;
+      case TSDB_DATA_TYPE_INT: {
+        switch (bind->buffer_type) {
+          case TSDB_DATA_TYPE_BOOL:
+          case TSDB_DATA_TYPE_TINYINT:
+          case TSDB_DATA_TYPE_SMALLINT:
+          case TSDB_DATA_TYPE_INT: {
+            u.v4 = *(int32_t*)bind->buffer;
+          } break;
+          case TSDB_DATA_TYPE_BIGINT: {
+            int64_t v = *(int64_t*)bind->buffer;
+            u.v4 = (int32_t)v;
+            if (v >= INT_MIN && v <= INT_MAX) break;
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+          case TSDB_DATA_TYPE_BINARY:
+          case TSDB_DATA_TYPE_NCHAR: {
+            int64_t v;
+            int n,r;
+            r = sscanf((const char*)bind->buffer, "%" PRId64 "%n", &v, &n);
+            if (r==1 && n==strlen((const char*)bind->buffer)) {
+              u.v4 = (int32_t)v;
+              if (v >= INT_MIN && v <= INT_MAX) break;
+            }
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+          case TSDB_DATA_TYPE_FLOAT:
+          case TSDB_DATA_TYPE_DOUBLE:
+          case TSDB_DATA_TYPE_TIMESTAMP:
+          default: {
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+        }
+        memcpy(data + param->offset, &u.v2, sizeof(u.v2));
+        return TSDB_CODE_SUCCESS;
+			} break;
+      case TSDB_DATA_TYPE_FLOAT: {
+        switch (bind->buffer_type) {
+          case TSDB_DATA_TYPE_BOOL:
+          case TSDB_DATA_TYPE_TINYINT: {
+            u.f4 = *(int8_t*)bind->buffer;
+          } break;
+          case TSDB_DATA_TYPE_SMALLINT: {
+            u.f4 = *(int16_t*)bind->buffer;
+          } break;
+          case TSDB_DATA_TYPE_INT: {
+            u.f4 = (float)*(int32_t*)bind->buffer;
+            // shall we check equality?
+          } break;
+          case TSDB_DATA_TYPE_BIGINT: {
+            u.f4 = (float)*(int64_t*)bind->buffer;
+            // shall we check equality?
+          } break;
+          case TSDB_DATA_TYPE_FLOAT: {
+            u.f4 = *(float*)bind->buffer;
+          } break;
+          case TSDB_DATA_TYPE_DOUBLE: {
+            u.f4 = *(float*)bind->buffer;
+            // shall we check equality?
+          } break;
+          case TSDB_DATA_TYPE_BINARY:
+          case TSDB_DATA_TYPE_NCHAR: {
+            float v;
+            int n,r;
+            r = sscanf((const char*)bind->buffer, "%f%n", &v, &n);
+            if (r==1 && n==strlen((const char*)bind->buffer)) {
+              u.f4 = v;
+              break;
+            }
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+          case TSDB_DATA_TYPE_TIMESTAMP:
+          default: {
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+        }
+        memcpy(data + param->offset, &u.f4, sizeof(u.f4));
+        return TSDB_CODE_SUCCESS;
+			} break;
+      case TSDB_DATA_TYPE_BIGINT: {
+        switch (bind->buffer_type) {
+          case TSDB_DATA_TYPE_BOOL:
+          case TSDB_DATA_TYPE_TINYINT: {
+            u.v8 = *(int8_t*)bind->buffer;
+          } break;
+          case TSDB_DATA_TYPE_SMALLINT: {
+            u.v8 = *(int16_t*)bind->buffer;
+          } break;
+          case TSDB_DATA_TYPE_INT: {
+            u.v8 = *(int32_t*)bind->buffer;
+          } break;
+          case TSDB_DATA_TYPE_BIGINT: {
+            u.v8 = *(int64_t*)bind->buffer;
+          } break;
+          case TSDB_DATA_TYPE_BINARY:
+          case TSDB_DATA_TYPE_NCHAR: {
+            int64_t v;
+            int n,r;
+            r = sscanf((const char*)bind->buffer, "%" PRId64 "%n", &v, &n);
+            if (r==1 && n==strlen((const char*)bind->buffer)) {
+              u.v8 = v;
+              break;
+            }
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+          case TSDB_DATA_TYPE_FLOAT:
+          case TSDB_DATA_TYPE_DOUBLE:
+          case TSDB_DATA_TYPE_TIMESTAMP:
+          default: {
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+        }
+        memcpy(data + param->offset, &u.v8, sizeof(u.v8));
+        return TSDB_CODE_SUCCESS;
+			} break;
+      case TSDB_DATA_TYPE_DOUBLE: {
+        switch (bind->buffer_type) {
+          case TSDB_DATA_TYPE_BOOL:
+          case TSDB_DATA_TYPE_TINYINT: {
+            u.f8 = *(int8_t*)bind->buffer;
+          } break;
+          case TSDB_DATA_TYPE_SMALLINT: {
+            u.f8 = *(int16_t*)bind->buffer;
+          } break;
+          case TSDB_DATA_TYPE_INT: {
+            u.f8 = *(int32_t*)bind->buffer;
+          } break;
+          case TSDB_DATA_TYPE_BIGINT: {
+            u.f8 = (double)*(int64_t*)bind->buffer;
+          } break;
+          case TSDB_DATA_TYPE_FLOAT: {
+            u.f8 = *(float*)bind->buffer;
+          } break;
+          case TSDB_DATA_TYPE_DOUBLE: {
+            u.f8 = *(double*)bind->buffer;
+          } break;
+          case TSDB_DATA_TYPE_BINARY:
+          case TSDB_DATA_TYPE_NCHAR: {
+            double v;
+            int n,r;
+            r = sscanf((const char*)bind->buffer, "%lf%n", &v, &n);
+            if (r==1 && n==strlen((const char*)bind->buffer)) {
+              u.f8 = v;
+              break;
+            }
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+          case TSDB_DATA_TYPE_TIMESTAMP:
+          default: {
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+        } break;
+        memcpy(data + param->offset, &u.f8, sizeof(u.f8));
+        return TSDB_CODE_SUCCESS;
+			} break;
+      case TSDB_DATA_TYPE_TIMESTAMP: {
+        switch (bind->buffer_type) {
+          case TSDB_DATA_TYPE_TIMESTAMP: {
+            u.v8 = *(int64_t*)bind->buffer;
+          } break;
+          case TSDB_DATA_TYPE_BINARY:
+          case TSDB_DATA_TYPE_NCHAR: {
+            // is this the correct way to call taosParseTime?
+            int32_t len = (int32_t)*bind->length;
+            if (taosParseTime(bind->buffer, &u.v8, len, 3, tsDaylight) == TSDB_CODE_SUCCESS) {
+              break;
+            }
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+          case TSDB_DATA_TYPE_BOOL:
+          case TSDB_DATA_TYPE_TINYINT:
+          case TSDB_DATA_TYPE_SMALLINT:
+          case TSDB_DATA_TYPE_INT:
+          case TSDB_DATA_TYPE_FLOAT:
+          case TSDB_DATA_TYPE_BIGINT:
+          case TSDB_DATA_TYPE_DOUBLE:
+          default: {
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+        } break;
+        memcpy(data + param->offset, &u.v8, sizeof(u.v8));
+        return TSDB_CODE_SUCCESS;
+			} break;
+      case TSDB_DATA_TYPE_BINARY: {
+        switch (bind->buffer_type) {
+          case TSDB_DATA_TYPE_BINARY: {
+            if ((*bind->length) > (uintptr_t)param->bytes) {
+              return TSDB_CODE_TSC_INVALID_VALUE;
+            }
+            size = (short)*bind->length;
+            STR_WITH_SIZE_TO_VARSTR(data + param->offset, bind->buffer, size);
+            return TSDB_CODE_SUCCESS;
+          } break;
+          case TSDB_DATA_TYPE_BOOL:
+          case TSDB_DATA_TYPE_TINYINT:
+          case TSDB_DATA_TYPE_SMALLINT:
+          case TSDB_DATA_TYPE_INT:
+          case TSDB_DATA_TYPE_FLOAT:
+          case TSDB_DATA_TYPE_BIGINT:
+          case TSDB_DATA_TYPE_DOUBLE:
+          case TSDB_DATA_TYPE_TIMESTAMP:
+          case TSDB_DATA_TYPE_NCHAR:
+          default: {
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+        }
+			} break;
+      case TSDB_DATA_TYPE_NCHAR: {
+        switch (bind->buffer_type) {
+          case TSDB_DATA_TYPE_NCHAR: {
+            size_t output = 0;
+            if (!taosMbsToUcs4(bind->buffer, *bind->length, varDataVal(data + param->offset), param->bytes - VARSTR_HEADER_SIZE, &output)) {
+              return TSDB_CODE_TSC_INVALID_VALUE;
+            }
+            varDataSetLen(data + param->offset, output);
+            return TSDB_CODE_SUCCESS;
+          } break;
+          case TSDB_DATA_TYPE_BOOL:
+          case TSDB_DATA_TYPE_TINYINT:
+          case TSDB_DATA_TYPE_SMALLINT:
+          case TSDB_DATA_TYPE_INT:
+          case TSDB_DATA_TYPE_FLOAT:
+          case TSDB_DATA_TYPE_BIGINT:
+          case TSDB_DATA_TYPE_DOUBLE:
+          case TSDB_DATA_TYPE_TIMESTAMP:
+          case TSDB_DATA_TYPE_BINARY:
+          default: {
+            return TSDB_CODE_TSC_INVALID_VALUE;
+          } break;
+        }
+			} break;
+      default: {
+        return TSDB_CODE_TSC_INVALID_VALUE;
+      } break;
+    }
+  }
+
  if (bind->buffer_type != param->type) {
    return TSDB_CODE_TSC_INVALID_VALUE;
  }
@ -637,3 +1019,80 @@ TAOS_RES *taos_stmt_use_result(TAOS_STMT* stmt) {
  pStmt->pSql = NULL;
  return result;
 }
+
+int taos_stmt_is_insert(TAOS_STMT *stmt, int *insert) {
+  STscStmt* pStmt = (STscStmt*)stmt;
+
+  if (stmt == NULL || pStmt->taos == NULL || pStmt->pSql == NULL) {
+    terrno = TSDB_CODE_TSC_DISCONNECTED;
+    return TSDB_CODE_TSC_DISCONNECTED;
+  }
+
+  if (insert) *insert = pStmt->isInsert;
+
+  return TSDB_CODE_SUCCESS;
+}
+
+int taos_stmt_num_params(TAOS_STMT *stmt, int *nums) {
+  STscStmt* pStmt = (STscStmt*)stmt;
+
+  if (stmt == NULL || pStmt->taos == NULL || pStmt->pSql == NULL) {
+    terrno = TSDB_CODE_TSC_DISCONNECTED;
+    return TSDB_CODE_TSC_DISCONNECTED;
+  }
+
+  if (pStmt->isInsert) {
+    SSqlObj* pSql = pStmt->pSql;
+    SSqlCmd *pCmd    = &pSql->cmd;
+    *nums = pCmd->numOfParams;
+    return TSDB_CODE_SUCCESS;
+  } else {
+    SNormalStmt* normal = &pStmt->normal;
+    *nums = normal->numParams;
+    return TSDB_CODE_SUCCESS;
+  }
+}
+
+int taos_stmt_get_param(TAOS_STMT *stmt, int idx, int *type, int *bytes) {
+  STscStmt* pStmt = (STscStmt*)stmt;
+
+  if (stmt == NULL || pStmt->taos == NULL || pStmt->pSql == NULL) {
+    terrno = TSDB_CODE_TSC_DISCONNECTED;
+    return TSDB_CODE_TSC_DISCONNECTED;
+  }
+
+  if (pStmt->isInsert) {
+    SSqlObj* pSql = pStmt->pSql;
+    SSqlCmd *pCmd    = &pSql->cmd;
+    STableDataBlocks* pBlock = taosArrayGetP(pCmd->pDataBlocks, 0);
+
+    assert(pCmd->numOfParams == pBlock->numOfParams);
+    if (idx < 0 || idx >= pBlock->numOfParams) return -1;
+
+    SParamInfo* param = pBlock->params + idx;
+    if (type) *type = param->type;
+    if (bytes) *bytes = param->bytes;
+
+    return TSDB_CODE_SUCCESS;
+  } else {
+    return TSDB_CODE_TSC_APP_ERROR;
+  }
+}
+
+const char *taos_data_type(int type) {
+  switch (type) {
+    case TSDB_DATA_TYPE_NULL:            return "TSDB_DATA_TYPE_NULL";
+    case TSDB_DATA_TYPE_BOOL:            return "TSDB_DATA_TYPE_BOOL";
+    case TSDB_DATA_TYPE_TINYINT:         return "TSDB_DATA_TYPE_TINYINT";
+    case TSDB_DATA_TYPE_SMALLINT:        return "TSDB_DATA_TYPE_SMALLINT";
+    case TSDB_DATA_TYPE_INT:             return "TSDB_DATA_TYPE_INT";
+    case TSDB_DATA_TYPE_BIGINT:          return "TSDB_DATA_TYPE_BIGINT";
+    case TSDB_DATA_TYPE_FLOAT:           return "TSDB_DATA_TYPE_FLOAT";
+    case TSDB_DATA_TYPE_DOUBLE:          return "TSDB_DATA_TYPE_DOUBLE";
+    case TSDB_DATA_TYPE_BINARY:          return "TSDB_DATA_TYPE_BINARY";
+    case TSDB_DATA_TYPE_TIMESTAMP:       return "TSDB_DATA_TYPE_TIMESTAMP";
+    case TSDB_DATA_TYPE_NCHAR:           return "TSDB_DATA_TYPE_NCHAR";
+    default: return "UNKNOWN";
+  }
+}
+
--- a/src/client/src/tscProfile.c
+++ b/src/client/src/tscProfile.c
@ -20,8 +20,10 @@
 #include "tutil.h"
 #include "taosmsg.h"

+#include "taos.h"
+
 void  tscSaveSlowQueryFp(void *handle, void *tmrId);
-void *tscSlowQueryConn = NULL;
+TAOS *tscSlowQueryConn = NULL;
 bool  tscSlowQueryConnInitialized = false;

 void tscInitConnCb(void *param, TAOS_RES *result, int code) {
@ -151,10 +153,12 @@ void tscKillQuery(STscObj *pObj, uint32_t killId) {

  pthread_mutex_unlock(&pObj->mutex);

-  if (pSql == NULL) return;
-
-  tscDebug("%p query is killed, queryId:%d", pSql, killId);
-  taos_stop_query(pSql);
+  if (pSql == NULL) {
+    tscError("failed to kill query, id:%d, it may have completed/terminated", killId);
+  } else {
+    tscDebug("%p query is killed, queryId:%d", pSql, killId);
+    taos_stop_query(pSql);
+  }
 }

 void tscAddIntoStreamList(SSqlStream *pStream) {
@ -242,6 +246,7 @@ int tscBuildQueryStreamDesc(void *pMsg, STscObj *pObj) {
    pQdesc->stime = htobe64(pSql->stime);
    pQdesc->queryId = htonl(pSql->queryId);
    pQdesc->useconds = htobe64(pSql->res.useconds);
+    pQdesc->qHandle = htobe64(pSql->res.qhandle);

    pHeartbeat->numOfQueries++;
    pQdesc++;
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@ -122,7 +122,7 @@ static int32_t doCheckForCreateTable(SSqlObj* pSql, int32_t subClauseIndex, SSql
 static int32_t doCheckForCreateFromStable(SSqlObj* pSql, SSqlInfo* pInfo);
 static int32_t doCheckForStream(SSqlObj* pSql, SSqlInfo* pInfo);
 static int32_t doCheckForQuery(SSqlObj* pSql, SQuerySQL* pQuerySql, int32_t index);
-static int32_t exprTreeFromSqlExpr(SSqlCmd* pCmd, tExprNode **pExpr, const tSQLExpr* pSqlExpr, SArray* pExprInfo, SQueryInfo* pQueryInfo, SArray* pCols);
+static int32_t exprTreeFromSqlExpr(SSqlCmd* pCmd, tExprNode **pExpr, const tSQLExpr* pSqlExpr, SQueryInfo* pQueryInfo, SArray* pCols, int64_t *uid);

 /*
 * Used during parsing query sql. Since the query sql usually small in length, error position
@ -190,7 +190,8 @@ int32_t tscToSQLCmd(SSqlObj* pSql, struct SSqlInfo* pInfo) {
  SSqlRes* pRes = &pSql->res;

  int32_t code = TSDB_CODE_SUCCESS;
-  if (!pInfo->valid) {
+  if (!pInfo->valid || terrno == TSDB_CODE_TSC_SQL_SYNTAX_ERROR) {
+    terrno = TSDB_CODE_SUCCESS;  // clear the error number
    return tscSQLSyntaxErrMsg(tscGetErrorMsgPayload(pCmd), NULL, pInfo->pzErrMsg);
  }

@ -626,6 +627,11 @@ int32_t parseIntervalClause(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SQuerySQL* pQ
    return TSDB_CODE_SUCCESS;
  }

+  // orderby column not set yet, set it to be the primary timestamp column
+  if (pQueryInfo->order.orderColId == INT32_MIN) {
+    pQueryInfo->order.orderColId = PRIMARYKEY_TIMESTAMP_COL_INDEX;
+  }
+
  // interval is not null
  SStrToken* t = &pQuerySql->interval;
  if (parseNatualDuration(t->z, t->n, &pQueryInfo->interval.interval, &pQueryInfo->interval.intervalUnit) != TSDB_CODE_SUCCESS) {
@ -1200,6 +1206,10 @@ int32_t setObjFullName(char* fullName, const char* account, SStrToken* pDB, SStr
  return (totalLen < TSDB_TABLE_FNAME_LEN) ? TSDB_CODE_SUCCESS : TSDB_CODE_TSC_INVALID_SQL;
 }

+static void tscInsertPrimaryTSSourceColumn(SQueryInfo* pQueryInfo, SColumnIndex* pIndex) {
+  SColumnIndex tsCol = {.tableIndex = pIndex->tableIndex, .columnIndex = PRIMARYKEY_TIMESTAMP_COL_INDEX};
+  tscColumnListInsert(pQueryInfo->colList, &tsCol);
+}
 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";
@ -1240,7 +1250,7 @@ static int32_t handleArithmeticExpr(SSqlCmd* pCmd, int32_t clauseIndex, int32_t
    tExprNode* pNode = NULL;
    SArray* colList = taosArrayInit(10, sizeof(SColIndex));

-    int32_t ret = exprTreeFromSqlExpr(pCmd, &pNode, pItem->pNode, pQueryInfo->exprList, pQueryInfo, colList);
+    int32_t ret = exprTreeFromSqlExpr(pCmd, &pNode, pItem->pNode, pQueryInfo, colList, NULL);
    if (ret != TSDB_CODE_SUCCESS) {
      taosArrayDestroy(colList);
      tExprTreeDestroy(&pNode, NULL);
@ -1275,6 +1285,8 @@ static int32_t handleArithmeticExpr(SSqlCmd* pCmd, int32_t clauseIndex, int32_t
    addExprParams(pExpr, c, TSDB_DATA_TYPE_BINARY, (int32_t)len, index.tableIndex);

    insertResultField(pQueryInfo, exprIndex, &columnList, sizeof(double), TSDB_DATA_TYPE_DOUBLE, pExpr->aliasName, pExpr);
+    // add ts column
+    tscInsertPrimaryTSSourceColumn(pQueryInfo, &index);

    tbufCloseWriter(&bw);
    taosArrayDestroy(colList);
@ -1294,17 +1306,17 @@ static int32_t handleArithmeticExpr(SSqlCmd* pCmd, int32_t clauseIndex, int32_t
    insertResultField(pQueryInfo, exprIndex, &columnList, sizeof(double), TSDB_DATA_TYPE_DOUBLE, aliasName, NULL);

    int32_t slot = tscNumOfFields(pQueryInfo) - 1;
-    SFieldSupInfo* pInfo = tscFieldInfoGetSupp(&pQueryInfo->fieldsInfo, slot);
+    SInternalField* pInfo = tscFieldInfoGetInternalField(&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->bytes      = sizeof(double);
      pArithExprInfo->interBytes = sizeof(double);
-      pArithExprInfo->type = TSDB_DATA_TYPE_DOUBLE;
+      pArithExprInfo->type       = TSDB_DATA_TYPE_DOUBLE;

-      int32_t ret = exprTreeFromSqlExpr(pCmd, &pArithExprInfo->pExpr, pItem->pNode, pQueryInfo->exprList, pQueryInfo, NULL);
+      int32_t ret = exprTreeFromSqlExpr(pCmd, &pArithExprInfo->pExpr, pItem->pNode, pQueryInfo, NULL, &pArithExprInfo->uid);
      if (ret != TSDB_CODE_SUCCESS) {
        tExprTreeDestroy(&pArithExprInfo->pExpr, NULL);
        return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), "invalid expression in select clause");
@ -1317,10 +1329,6 @@ static int32_t handleArithmeticExpr(SSqlCmd* pCmd, int32_t clauseIndex, int32_t
  return TSDB_CODE_SUCCESS;
 }

-static void tscInsertPrimaryTSSourceColumn(SQueryInfo* pQueryInfo, SColumnIndex* pIndex) {
-  SColumnIndex tsCol = {.tableIndex = pIndex->tableIndex, .columnIndex = PRIMARYKEY_TIMESTAMP_COL_INDEX};
-  tscColumnListInsert(pQueryInfo->colList, &tsCol);
-}

 static void addProjectQueryCol(SQueryInfo* pQueryInfo, int32_t startPos, SColumnIndex* pIndex, tSQLExprItem* pItem) {
  SSqlExpr* pExpr = doAddProjectCol(pQueryInfo, startPos, pIndex->columnIndex, pIndex->tableIndex);
@ -1345,6 +1353,32 @@ static void addProjectQueryCol(SQueryInfo* pQueryInfo, int32_t startPos, SColumn
  insertResultField(pQueryInfo, startPos, &ids, pExpr->resBytes, (int8_t)pExpr->resType, pExpr->aliasName, pExpr);
 }

+static void addPrimaryTsColIntoResult(SQueryInfo* pQueryInfo) {
+  // primary timestamp column has been added already
+  size_t size = tscSqlExprNumOfExprs(pQueryInfo);
+  for (int32_t i = 0; i < size; ++i) {
+    SSqlExpr* pExpr = tscSqlExprGet(pQueryInfo, i);
+    if (pExpr->functionId == TSDB_FUNC_PRJ && pExpr->colInfo.colId == PRIMARYKEY_TIMESTAMP_COL_INDEX) {
+      return;
+    }
+  }
+
+  SColumnIndex index = {0};
+
+  // set the constant column value always attached to first table.
+  STableMetaInfo* pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
+  SSchema* pSchema = tscGetTableColumnSchema(pTableMetaInfo->pTableMeta, PRIMARYKEY_TIMESTAMP_COL_INDEX);
+
+  // add the timestamp column into the output columns
+  int32_t numOfCols = (int32_t)tscSqlExprNumOfExprs(pQueryInfo);
+  tscAddSpecialColumnForSelect(pQueryInfo, numOfCols, TSDB_FUNC_PRJ, &index, pSchema, TSDB_COL_NORMAL);
+
+  SInternalField* pSupInfo = tscFieldInfoGetInternalField(&pQueryInfo->fieldsInfo, numOfCols);
+  pSupInfo->visible = false;
+
+  pQueryInfo->type |= TSDB_QUERY_TYPE_PROJECTION_QUERY;
+}
+
 int32_t parseSelectClause(SSqlCmd* pCmd, int32_t clauseIndex, tSQLExprList* pSelection, bool isSTable, bool joinQuery) {
  assert(pSelection != NULL && pCmd != NULL);

@ -1398,20 +1432,7 @@ int32_t parseSelectClause(SSqlCmd* pCmd, int32_t clauseIndex, tSQLExprList* pSel
  // there is only one user-defined column in the final result field, add the timestamp column.
  size_t numOfSrcCols = taosArrayGetSize(pQueryInfo->colList);
  if (numOfSrcCols <= 0 && !tscQueryTags(pQueryInfo)) {
-    SColumnIndex index = {0};
-
-    // set the constant column value always attached to first table.
-    STableMetaInfo* pTableMetaInfo = tscGetTableMetaInfoFromCmd(pCmd, clauseIndex, 0);
-    SSchema* pSchema = tscGetTableColumnSchema(pTableMetaInfo->pTableMeta, PRIMARYKEY_TIMESTAMP_COL_INDEX);
-
-    // add the timestamp column into the output columns
-    int32_t numOfCols = (int32_t)tscSqlExprNumOfExprs(pQueryInfo);
-    tscAddSpecialColumnForSelect(pQueryInfo, numOfCols, TSDB_FUNC_PRJ, &index, pSchema, TSDB_COL_NORMAL);
-
-    SFieldSupInfo* pSupInfo = tscFieldInfoGetSupp(&pQueryInfo->fieldsInfo, numOfCols);
-    pSupInfo->visible = false;
-
-    pQueryInfo->type |= TSDB_QUERY_TYPE_PROJECTION_QUERY;
+    addPrimaryTsColIntoResult(pQueryInfo);
  }

  if (!functionCompatibleCheck(pQueryInfo, joinQuery)) {
@ -1449,7 +1470,7 @@ int32_t insertResultField(SQueryInfo* pQueryInfo, int32_t outputIndex, SColumnLi
  }
  
  TAOS_FIELD f = tscCreateField(type, fieldName, bytes);
-  SFieldSupInfo* pInfo = tscFieldInfoInsert(&pQueryInfo->fieldsInfo, outputIndex, &f);
+  SInternalField* pInfo = tscFieldInfoInsert(&pQueryInfo->fieldsInfo, outputIndex, &f);
  pInfo->pSqlExpr = pSqlExpr;
  
  return TSDB_CODE_SUCCESS;
@ -1603,8 +1624,8 @@ int32_t addProjectionExprAndResultField(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, t
  return TSDB_CODE_SUCCESS;
 }

-static int32_t setExprInfoForFunctions(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SSchema* pSchema, SConvertFunc cvtFunc, char* aliasName,
-                                       int32_t resColIdx, SColumnIndex* pColIndex) {
+static int32_t setExprInfoForFunctions(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SSchema* pSchema, SConvertFunc cvtFunc,
+    char* aliasName, int32_t resColIdx, SColumnIndex* pColIndex, bool finalResult) {
  const char* msg1 = "not support column types";

  int16_t type = 0;
@ -1650,8 +1671,13 @@ static int32_t setExprInfoForFunctions(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SS
  SColumnIndex index = {.tableIndex = pColIndex->tableIndex, .columnIndex = PRIMARYKEY_TIMESTAMP_COL_INDEX};
  tscColumnListInsert(pQueryInfo->colList, &index);

+  // if it is not in the final result, do not add it
  SColumnList ids = getColumnList(1, pColIndex->tableIndex, pColIndex->columnIndex);
-  insertResultField(pQueryInfo, resColIdx, &ids, bytes, (int8_t)type, columnName, pExpr);
+  if (finalResult) {
+    insertResultField(pQueryInfo, resColIdx, &ids, bytes, (int8_t)type, columnName, pExpr);
+  } else {
+    tscColumnListInsert(pQueryInfo->colList, &(ids.ids[0]));
+  }

  return TSDB_CODE_SUCCESS;
 }
@ -1926,7 +1952,7 @@ int32_t addExprAndResultField(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, int32_t col

            for (int32_t j = 0; j < tscGetNumOfColumns(pTableMetaInfo->pTableMeta); ++j) {
              index.columnIndex = j;
-              if (setExprInfoForFunctions(pCmd, pQueryInfo, pSchema, cvtFunc, pItem->aliasName, colIndex++, &index) != 0) {
+              if (setExprInfoForFunctions(pCmd, pQueryInfo, pSchema, cvtFunc, pItem->aliasName, colIndex++, &index, finalResult) != 0) {
                return TSDB_CODE_TSC_INVALID_SQL;
              }
            }
@ -1943,7 +1969,8 @@ int32_t addExprAndResultField(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, int32_t col
            if ((index.columnIndex >= tscGetNumOfColumns(pTableMetaInfo->pTableMeta)) || (index.columnIndex < 0)) {
              return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg6);
            }
-            if (setExprInfoForFunctions(pCmd, pQueryInfo, pSchema, cvtFunc, pItem->aliasName, colIndex + i, &index) != 0) {
+
+            if (setExprInfoForFunctions(pCmd, pQueryInfo, pSchema, cvtFunc, pItem->aliasName, colIndex + i, &index, finalResult) != 0) {
              return TSDB_CODE_TSC_INVALID_SQL;
            }

@ -1980,7 +2007,7 @@ int32_t addExprAndResultField(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, int32_t col

          for (int32_t i = 0; i < tscGetNumOfColumns(pTableMetaInfo->pTableMeta); ++i) {
            SColumnIndex index = {.tableIndex = j, .columnIndex = i};
-            if (setExprInfoForFunctions(pCmd, pQueryInfo, pSchema, cvtFunc, pItem->aliasName, colIndex, &index) != 0) {
+            if (setExprInfoForFunctions(pCmd, pQueryInfo, pSchema, cvtFunc, pItem->aliasName, colIndex, &index, finalResult) != 0) {
              return TSDB_CODE_TSC_INVALID_SQL;
            }

@ -3358,10 +3385,26 @@ static int32_t validateSQLExpr(SSqlCmd* pCmd, tSQLExpr* pExpr, SQueryInfo* pQuer
  
    tSQLExprItem item = {.pNode = pExpr, .aliasName = NULL};
  
-    // sql function in selection clause, append sql function info in pSqlCmd structure sequentially
+    // sql function list in selection clause.
+    // Append the sqlExpr into exprList of pQueryInfo structure sequentially
    if (addExprAndResultField(pCmd, pQueryInfo, outputIndex, &item, false) != TSDB_CODE_SUCCESS) {
      return TSDB_CODE_TSC_INVALID_SQL;
    }
+
+    // It is invalid in case of more than one sqlExpr, such as first(ts, k) - last(ts, k)
+    int32_t inc = (int32_t) tscSqlExprNumOfExprs(pQueryInfo) - outputIndex;
+    if (inc > 1) {
+      return TSDB_CODE_TSC_INVALID_SQL;
+    }
+
+    // Not supported data type in arithmetic expression
+    for(int32_t i = 0; i < inc; ++i) {
+      SSqlExpr* p1 = tscSqlExprGet(pQueryInfo, i + outputIndex);
+      int16_t t = p1->resType;
+      if (t == TSDB_DATA_TYPE_BINARY || t == TSDB_DATA_TYPE_NCHAR || t == TSDB_DATA_TYPE_BOOL || t == TSDB_DATA_TYPE_TIMESTAMP) {
+        return TSDB_CODE_TSC_INVALID_SQL;
+      }
+    }
  }

  return TSDB_CODE_SUCCESS;
@ -4036,7 +4079,7 @@ static int32_t getTagQueryCondExpr(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SCondE
    tExprNode* p = NULL;
  
    SArray* colList = taosArrayInit(10, sizeof(SColIndex));
-    ret = exprTreeFromSqlExpr(pCmd, &p, p1, NULL, pQueryInfo, colList);
+    ret = exprTreeFromSqlExpr(pCmd, &p, p1, pQueryInfo, colList, NULL);
    SBufferWriter bw = tbufInitWriter(NULL, false);

    TRY(0) {
@ -4363,14 +4406,13 @@ int32_t parseFillClause(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SQuerySQL* pQuery

 static void setDefaultOrderInfo(SQueryInfo* pQueryInfo) {
  /* set default timestamp order information for all queries */
-  pQueryInfo->order.order = TSDB_ORDER_ASC;
  STableMetaInfo* pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);

+  pQueryInfo->order.order = TSDB_ORDER_ASC;
  if (isTopBottomQuery(pQueryInfo)) {
-    pQueryInfo->order.order = TSDB_ORDER_ASC;
    pQueryInfo->order.orderColId = PRIMARYKEY_TIMESTAMP_COL_INDEX;
-  } else {
-    pQueryInfo->order.orderColId = -1;
+  } else { // in case of select tbname from super_table, the defualt order column can not be the primary ts column
+    pQueryInfo->order.orderColId = INT32_MIN;
  }

  /* for super table query, set default ascending order for group output */
@ -4474,6 +4516,11 @@ int32_t parseOrderbyClause(SSqlCmd* pCmd, SQueryInfo* pQueryInfo, SQuerySQL* pQu
      } else {
        pQueryInfo->order.order = pSortorder->a[0].sortOrder;
        pQueryInfo->order.orderColId = PRIMARYKEY_TIMESTAMP_COL_INDEX;
+
+        // orderby ts query on super table
+        if (tscOrderedProjectionQueryOnSTable(pQueryInfo, 0)) {
+          addPrimaryTsColIntoResult(pQueryInfo);
+        }
      }
    }

@ -4703,7 +4750,7 @@ int32_t setAlterTableInfo(SSqlObj* pSql, struct SSqlInfo* pInfo) {

    // validate the length of binary
    if ((pTagsSchema->type == TSDB_DATA_TYPE_BINARY || pTagsSchema->type == TSDB_DATA_TYPE_NCHAR) &&
-        (pVarList->a[1].pVar.nLen + VARSTR_HEADER_SIZE) > pTagsSchema->bytes) {
+        varDataTLen(pAlterSQL->tagData.data) > pTagsSchema->bytes) {
      return invalidSqlErrMsg(tscGetErrorMsgPayload(pCmd), msg14);
    }

@ -5229,26 +5276,6 @@ int32_t parseCreateDBOptions(SSqlCmd* pCmd, SCreateDBInfo* pCreateDbSql) {
  return TSDB_CODE_SUCCESS;
 }

-//void tscAddTimestampColumn(SQueryInfo* pQueryInfo, int16_t functionId, int16_t tableIndex) {
-//  // the first column not timestamp column, add it
-//  SSqlExpr* pExpr = NULL;
-//  if (tscSqlExprNumOfExprs(pQueryInfo) > 0) {
-//    pExpr = tscSqlExprGet(pQueryInfo, 0);
-//  }
-//
-//  if (pExpr == NULL || pExpr->colInfo.colId != PRIMARYKEY_TIMESTAMP_COL_INDEX || pExpr->functionId != functionId) {
-//    SColumnIndex index = {tableIndex, PRIMARYKEY_TIMESTAMP_COL_INDEX};
-//
-//    pExpr = tscSqlExprInsert(pQueryInfo, 0, functionId, &index, TSDB_DATA_TYPE_TIMESTAMP, TSDB_KEYSIZE, TSDB_KEYSIZE, false);
-//    pExpr->colInfo.flag = TSDB_COL_NORMAL;
-//
-//    // NOTE: tag column does not add to source column list
-//    SColumnList ids = getColumnList(1, tableIndex, PRIMARYKEY_TIMESTAMP_COL_INDEX);
-//
-//    insertResultField(pQueryInfo, 0, &ids, TSDB_KEYSIZE, TSDB_DATA_TYPE_TIMESTAMP, "ts", pExpr);
-//  }
-//}
-
 void addGroupInfoForSubquery(SSqlObj* pParentObj, SSqlObj* pSql, int32_t subClauseIndex, int32_t tableIndex) {
  SQueryInfo* pParentQueryInfo = tscGetQueryInfoDetail(&pParentObj->cmd, subClauseIndex);

@ -5305,7 +5332,7 @@ void doAddGroupColumnForSubquery(SQueryInfo* pQueryInfo, int32_t tagIndex) {

  tscAddSpecialColumnForSelect(pQueryInfo, (int32_t)size, TSDB_FUNC_PRJ, &colIndex, pSchema, TSDB_COL_NORMAL);

-  SFieldSupInfo* pInfo = tscFieldInfoGetSupp(&pQueryInfo->fieldsInfo, (int32_t)size);
+  SInternalField* pInfo = tscFieldInfoGetInternalField(&pQueryInfo->fieldsInfo, (int32_t)size);
  doLimitOutputNormalColOfGroupby(pInfo->pSqlExpr);
  pInfo->visible = false;
 }
@ -6269,6 +6296,11 @@ int32_t doCheckForQuery(SSqlObj* pSql, SQuerySQL* pQuerySql, int32_t index) {
    return TSDB_CODE_TSC_INVALID_SQL;
  }

+  // set order by info
+  if (parseOrderbyClause(pCmd, pQueryInfo, pQuerySql, tscGetTableSchema(pTableMetaInfo->pTableMeta)) != TSDB_CODE_SUCCESS) {
+    return TSDB_CODE_TSC_INVALID_SQL;
+  }
+
  // set interval value
  if (parseIntervalClause(pCmd, pQueryInfo, pQuerySql) != TSDB_CODE_SUCCESS) {
    return TSDB_CODE_TSC_INVALID_SQL;
@ -6279,11 +6311,6 @@ int32_t doCheckForQuery(SSqlObj* pSql, SQuerySQL* pQuerySql, int32_t index) {
    }
  }

-  // set order by info
-  if (parseOrderbyClause(pCmd, pQueryInfo, pQuerySql, tscGetTableSchema(pTableMetaInfo->pTableMeta)) != TSDB_CODE_SUCCESS) {
-    return TSDB_CODE_TSC_INVALID_SQL;
-  }
-
  // user does not specified the query time window, twa is not allowed in such case.
  if ((pQueryInfo->window.skey == INT64_MIN || pQueryInfo->window.ekey == INT64_MAX ||
       (pQueryInfo->window.ekey == INT64_MAX / 1000 && tinfo.precision == TSDB_TIME_PRECISION_MILLI)) && tscIsTWAQuery(pQueryInfo)) {
@ -6350,19 +6377,19 @@ int32_t doCheckForQuery(SSqlObj* pSql, SQuerySQL* pQuerySql, int32_t index) {
  return TSDB_CODE_SUCCESS;  // Does not build query message here
 }

-int32_t exprTreeFromSqlExpr(SSqlCmd* pCmd, tExprNode **pExpr, const tSQLExpr* pSqlExpr, SArray* pExprInfo, SQueryInfo* pQueryInfo, SArray* pCols) {
+int32_t exprTreeFromSqlExpr(SSqlCmd* pCmd, tExprNode **pExpr, const tSQLExpr* pSqlExpr, SQueryInfo* pQueryInfo, SArray* pCols, int64_t *uid) {
  tExprNode* pLeft = NULL;
  tExprNode* pRight= NULL;
  
  if (pSqlExpr->pLeft != NULL) {
-    int32_t ret = exprTreeFromSqlExpr(pCmd, &pLeft, pSqlExpr->pLeft, pExprInfo, pQueryInfo, pCols);
+    int32_t ret = exprTreeFromSqlExpr(pCmd, &pLeft, pSqlExpr->pLeft, pQueryInfo, pCols, uid);
    if (ret != TSDB_CODE_SUCCESS) {
      return ret;
    }
  }
  
  if (pSqlExpr->pRight != NULL) {
-    int32_t ret = exprTreeFromSqlExpr(pCmd, &pRight, pSqlExpr->pRight, pExprInfo, pQueryInfo, pCols);
+    int32_t ret = exprTreeFromSqlExpr(pCmd, &pRight, pSqlExpr->pRight, pQueryInfo, pCols, uid);
    if (ret != TSDB_CODE_SUCCESS) {
      return ret;
    }
@ -6389,14 +6416,19 @@ int32_t exprTreeFromSqlExpr(SSqlCmd* pCmd, tExprNode **pExpr, const tSQLExpr* pS
      strncpy((*pExpr)->pSchema->name, pSqlExpr->operand.z, pSqlExpr->operand.n);
      
      // set the input column data byte and type.
-      size_t size = taosArrayGetSize(pExprInfo);
+      size_t size = taosArrayGetSize(pQueryInfo->exprList);
      
      for (int32_t i = 0; i < size; ++i) {
-        SSqlExpr* p1 = taosArrayGetP(pExprInfo, i);
+        SSqlExpr* p1 = taosArrayGetP(pQueryInfo->exprList, i);
        
        if (strcmp((*pExpr)->pSchema->name, p1->aliasName) == 0) {
-          (*pExpr)->pSchema->type = (uint8_t)p1->resType;
+          (*pExpr)->pSchema->type  = (uint8_t)p1->resType;
          (*pExpr)->pSchema->bytes = p1->resBytes;
+
+          if (uid != NULL) {
+            *uid = p1->uid;
+          }
+
          break;
        }
      }
--- a/src/client/src/tscSchemaUtil.c
+++ b/src/client/src/tscSchemaUtil.c
@ -145,10 +145,11 @@ static void tscInitCorVgroupInfo(SCMCorVgroupInfo *corVgroupInfo, SCMVgroupInfo
  corVgroupInfo->inUse = 0;
  corVgroupInfo->numOfEps = vgroupInfo->numOfEps;
  for (int32_t i = 0; i < corVgroupInfo->numOfEps; i++) {
-    strncpy(corVgroupInfo->epAddr[i].fqdn, vgroupInfo->epAddr[i].fqdn, TSDB_FQDN_LEN);
+    corVgroupInfo->epAddr[i].fqdn = strdup(vgroupInfo->epAddr[i].fqdn);
    corVgroupInfo->epAddr[i].port = vgroupInfo->epAddr[i].port;
  }
 }
+
 STableMeta* tscCreateTableMetaFromMsg(STableMetaMsg* pTableMetaMsg, size_t* size) {
  assert(pTableMetaMsg != NULL);
  
@ -162,9 +163,19 @@ STableMeta* tscCreateTableMetaFromMsg(STableMetaMsg* pTableMetaMsg, size_t* size
    .numOfColumns = pTableMetaMsg->numOfColumns,
  };
  
-  pTableMeta->id.tid = pTableMetaMsg->sid;
+  pTableMeta->id.tid = pTableMetaMsg->tid;
  pTableMeta->id.uid = pTableMetaMsg->uid;
-  pTableMeta->vgroupInfo = pTableMetaMsg->vgroup;
+
+  SCMVgroupInfo* pVgroupInfo = &pTableMeta->vgroupInfo;
+  pVgroupInfo->numOfEps = pTableMetaMsg->vgroup.numOfEps;
+  pVgroupInfo->vgId = pTableMetaMsg->vgroup.vgId;
+
+  for(int32_t i = 0; i < pVgroupInfo->numOfEps; ++i) {
+    SEpAddrMsg* pEpMsg = &pTableMetaMsg->vgroup.epAddr[i];
+
+    pVgroupInfo->epAddr[i].fqdn = strndup(pEpMsg->fqdn, tListLen(pEpMsg->fqdn));
+    pVgroupInfo->epAddr[i].port = pEpMsg->port;
+  }

  tscInitCorVgroupInfo(&pTableMeta->corVgroupInfo, &pTableMeta->vgroupInfo);

--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@ -24,7 +24,6 @@
 #include "tschemautil.h"
 #include "tsclient.h"
 #include "ttimer.h"
-#include "tutil.h"
 #include "tlockfree.h"

 SRpcCorEpSet  tscMgmtEpSet;
@ -125,9 +124,11 @@ static void tscUpdateVgroupInfo(SSqlObj *pObj, SRpcEpSet *pEpSet) {
  pVgroupInfo->inUse = pEpSet->inUse;
  pVgroupInfo->numOfEps = pEpSet->numOfEps;
  for (int32_t i = 0; i < pVgroupInfo->numOfEps; i++) {
-    tstrncpy(pVgroupInfo->epAddr[i].fqdn, pEpSet->fqdn[i], TSDB_FQDN_LEN);
+    taosTFree(pVgroupInfo->epAddr[i].fqdn);
+    pVgroupInfo->epAddr[i].fqdn = strndup(pEpSet->fqdn[i], tListLen(pEpSet->fqdn[i]));
    pVgroupInfo->epAddr[i].port = pEpSet->port[i];
  }
+
  tscDebug("after: EndPoint in use: %d", pVgroupInfo->inUse);
  taosCorEndWrite(&pVgroupInfo->version);
 }
@ -198,15 +199,19 @@ void tscProcessActivityTimer(void *handle, void *tmrId) {
    return;
  }

-  if (tscShouldFreeHeartBeat(pHB)) {
-    tscDebug("%p free HB object and release connection", pHB);
-    pObj->pHb = 0;
-    taos_free_result(pHB);
-  } else {
-    int32_t code = tscProcessSql(pHB);
-    if (code != TSDB_CODE_SUCCESS) {
-      tscError("%p failed to sent HB to server, reason:%s", pHB, tstrerror(code));
-    }
+  void** p = taosCacheAcquireByKey(tscObjCache, &pHB, sizeof(TSDB_CACHE_PTR_TYPE));
+  if (p == NULL) {
+    tscWarn("%p HB object has been released already", pHB);
+    return;
+  }
+
+  assert(*pHB->self == pHB);
+
+  int32_t code = tscProcessSql(pHB);
+  taosCacheRelease(tscObjCache, (void**) &p, false);
+
+  if (code != TSDB_CODE_SUCCESS) {
+    tscError("%p failed to sent HB to server, reason:%s", pHB, tstrerror(code));
  }
 }

@ -464,35 +469,6 @@ int tscProcessSql(SSqlObj *pSql) {
  return doProcessSql(pSql);
 }

-void tscKillSTableQuery(SSqlObj *pSql) {
-  SSqlCmd* pCmd = &pSql->cmd;
-  
-  SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);
-  if (!tscIsTwoStageSTableQuery(pQueryInfo, 0)) {
-    return;
-  }
-
-  pSql->res.code = TSDB_CODE_TSC_QUERY_CANCELLED;
-
-  for (int i = 0; i < pSql->numOfSubs; ++i) {
-    // NOTE: pSub may have been released already here
-    SSqlObj *pSub = pSql->pSubs[i];
-    if (pSub == NULL) {
-      continue;
-    }
-
-    pSub->res.code = TSDB_CODE_TSC_QUERY_CANCELLED;
-    if (pSub->pRpcCtx != NULL) {
-      rpcCancelRequest(pSub->pRpcCtx);
-      pSub->pRpcCtx = NULL;
-    }
-
-    tscQueueAsyncRes(pSub); // async res? not other functions?
-  }
-
-  tscDebug("%p super table query cancelled", pSql);
-}
-
 int tscBuildFetchMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
  SRetrieveTableMsg *pRetrieveMsg = (SRetrieveTableMsg *) pSql->cmd.payload;
  pRetrieveMsg->qhandle = htobe64(pSql->res.qhandle);
@ -1392,7 +1368,7 @@ static int tscSetResultPointer(SQueryInfo *pQueryInfo, SSqlRes *pRes) {

  for (int i = 0; i < pQueryInfo->fieldsInfo.numOfOutput; ++i) {
    int16_t offset = tscFieldInfoGetOffset(pQueryInfo, i);
-    pRes->tsrow[i] = ((char*) pRes->data + offset * pRes->numOfRows);
+    pRes->tsrow[i] = (unsigned char*)((char*) pRes->data + offset * pRes->numOfRows);
  }

  return 0;
@ -1451,7 +1427,7 @@ int tscProcessLocalRetrieveRsp(SSqlObj *pSql) {

 int tscProcessRetrieveLocalMergeRsp(SSqlObj *pSql) {
  SSqlRes *pRes = &pSql->res;
-  SSqlCmd *pCmd = &pSql->cmd;
+  SSqlCmd* pCmd = &pSql->cmd;

  int32_t code = pRes->code;
  if (pRes->code != TSDB_CODE_SUCCESS) {
@ -1494,6 +1470,7 @@ int tscBuildConnectMsg(SSqlObj *pSql, SSqlInfo *pInfo) {

  SCMConnectMsg *pConnect = (SCMConnectMsg*)pCmd->payload;

+  // TODO refactor full_name
  char *db;  // ugly code to move the space
  db = strstr(pObj->db, TS_PATH_DELIMITER);
  db = (db == NULL) ? pObj->db : db + 1;
@ -1501,6 +1478,9 @@ int tscBuildConnectMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
  tstrncpy(pConnect->clientVersion, version, sizeof(pConnect->clientVersion));
  tstrncpy(pConnect->msgVersion, "", sizeof(pConnect->msgVersion));

+  pConnect->pid = htonl(taosGetPId());
+  taosGetCurrentAPPName(pConnect->appName, NULL);
+
  return TSDB_CODE_SUCCESS;
 }

@ -1653,6 +1633,10 @@ int tscBuildHeartBeatMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
  SCMHeartBeatMsg *pHeartbeat = (SCMHeartBeatMsg *)pCmd->payload;
  pHeartbeat->numOfQueries = numOfQueries;
  pHeartbeat->numOfStreams = numOfStreams;
+
+  pHeartbeat->pid = htonl(taosGetPId());
+  taosGetCurrentAPPName(pHeartbeat->appName, NULL);
+
  int msgLen = tscBuildQueryStreamDesc(pHeartbeat, pObj);

  pthread_mutex_unlock(&pObj->mutex);
@ -1666,7 +1650,7 @@ int tscBuildHeartBeatMsg(SSqlObj *pSql, SSqlInfo *pInfo) {
 int tscProcessTableMetaRsp(SSqlObj *pSql) {
  STableMetaMsg *pMetaMsg = (STableMetaMsg *)pSql->res.pRsp;

-  pMetaMsg->sid = htonl(pMetaMsg->sid);
+  pMetaMsg->tid = htonl(pMetaMsg->tid);
  pMetaMsg->sversion = htons(pMetaMsg->sversion);
  pMetaMsg->tversion = htons(pMetaMsg->tversion);
  pMetaMsg->vgroup.vgId = htonl(pMetaMsg->vgroup.vgId);
@ -1676,9 +1660,9 @@ int tscProcessTableMetaRsp(SSqlObj *pSql) {
  pMetaMsg->numOfColumns = htons(pMetaMsg->numOfColumns);

  if ((pMetaMsg->tableType != TSDB_SUPER_TABLE) &&
-      (pMetaMsg->sid <= 0 || pMetaMsg->vgroup.vgId < 2 || pMetaMsg->vgroup.numOfEps <= 0)) {
+      (pMetaMsg->tid <= 0 || pMetaMsg->vgroup.vgId < 2 || pMetaMsg->vgroup.numOfEps <= 0)) {
    tscError("invalid value in table numOfEps:%d, vgId:%d tid:%d, name:%s", pMetaMsg->vgroup.numOfEps, pMetaMsg->vgroup.vgId,
-             pMetaMsg->sid, pMetaMsg->tableId);
+             pMetaMsg->tid, pMetaMsg->tableId);
    return TSDB_CODE_TSC_INVALID_VALUE;
  }

@ -1857,22 +1841,30 @@ int tscProcessSTableVgroupRsp(SSqlObj *pSql) {
  SSqlCmd* pCmd = &parent->cmd;
  for(int32_t i = 0; i < pStableVgroup->numOfTables; ++i) {
    STableMetaInfo *pInfo = tscGetTableMetaInfoFromCmd(pCmd, pCmd->clauseIndex, i);
-    SVgroupsInfo *  pVgroupInfo = (SVgroupsInfo *)pMsg;
-    pVgroupInfo->numOfVgroups = htonl(pVgroupInfo->numOfVgroups);

-    size_t size = sizeof(SCMVgroupInfo) * pVgroupInfo->numOfVgroups + sizeof(SVgroupsInfo);
-    pInfo->vgroupList = calloc(1, size);
+    SVgroupsMsg *  pVgroupMsg = (SVgroupsMsg *) pMsg;
+    pVgroupMsg->numOfVgroups = htonl(pVgroupMsg->numOfVgroups);
+
+    size_t size = sizeof(SCMVgroupMsg) * pVgroupMsg->numOfVgroups + sizeof(SVgroupsMsg);
+
+    size_t vgroupsz = sizeof(SCMVgroupInfo) * pVgroupMsg->numOfVgroups + sizeof(SVgroupsInfo);
+    pInfo->vgroupList = calloc(1, vgroupsz);
    assert(pInfo->vgroupList != NULL);

-    memcpy(pInfo->vgroupList, pVgroupInfo, size);
+    pInfo->vgroupList->numOfVgroups = pVgroupMsg->numOfVgroups;
    for (int32_t j = 0; j < pInfo->vgroupList->numOfVgroups; ++j) {
      //just init, no need to lock
      SCMVgroupInfo *pVgroups = &pInfo->vgroupList->vgroups[j];
-      pVgroups->vgId = htonl(pVgroups->vgId);
-      assert(pVgroups->numOfEps >= 1);
+
+      SCMVgroupMsg *vmsg = &pVgroupMsg->vgroups[j];
+      pVgroups->vgId = htonl(vmsg->vgId);
+      pVgroups->numOfEps = vmsg->numOfEps;
+
+      assert(pVgroups->numOfEps >= 1 && pVgroups->vgId >= 1);

      for (int32_t k = 0; k < pVgroups->numOfEps; ++k) {
-        pVgroups->epAddr[k].port = htons(pVgroups->epAddr[k].port);
+        pVgroups->epAddr[k].port = htons(vmsg->epAddr[k].port);
+        pVgroups->epAddr[k].fqdn = strndup(vmsg->epAddr[k].fqdn, tListLen(vmsg->epAddr[k].fqdn));
      }
    }

@ -1908,7 +1900,7 @@ int tscProcessShowRsp(SSqlObj *pSql) {
  pMetaMsg->numOfColumns = ntohs(pMetaMsg->numOfColumns);

  pSchema = pMetaMsg->schema;
-  pMetaMsg->sid = ntohs(pMetaMsg->sid);
+  pMetaMsg->tid = ntohs(pMetaMsg->tid);
  for (int i = 0; i < pMetaMsg->numOfColumns; ++i) {
    pSchema->bytes = htons(pSchema->bytes);
    pSchema++;
@ -1942,7 +1934,7 @@ int tscProcessShowRsp(SSqlObj *pSql) {
    tscColumnListInsert(pQueryInfo->colList, &index);
    
    TAOS_FIELD f = tscCreateField(pSchema->type, pSchema->name, pSchema->bytes);
-    SFieldSupInfo* pInfo = tscFieldInfoAppend(pFieldInfo, &f);
+    SInternalField* pInfo = tscFieldInfoAppend(pFieldInfo, &f);
    
    pInfo->pSqlExpr = tscSqlExprAppend(pQueryInfo, TSDB_FUNC_TS_DUMMY, &index,
                     pTableSchema[i].type, pTableSchema[i].bytes, pTableSchema[i].bytes, false);
--- a/src/client/src/tscSql.c
+++ b/src/client/src/tscSql.c
@ -26,7 +26,9 @@
 #include "tsclient.h"
 #include "ttokendef.h"
 #include "tutil.h"
+#include "ttimer.h"
 #include "tscProfile.h"
+#include "ttimer.h"

 static bool validImpl(const char* str, size_t maxsize) {
  if (str == NULL) {
@ -49,8 +51,8 @@ static bool validPassword(const char* passwd) {
  return validImpl(passwd, TSDB_PASSWORD_LEN - 1);
 }

-SSqlObj *taosConnectImpl(const char *ip, const char *user, const char *pass, const char *auth, const char *db,
-                         uint16_t port, void (*fp)(void *, TAOS_RES *, int), void *param, void **taos) {
+static SSqlObj *taosConnectImpl(const char *ip, const char *user, const char *pass, const char *auth, const char *db,
+                         uint16_t port, void (*fp)(void *, TAOS_RES *, int), void *param, TAOS **taos) {
  taos_init();

  if (!validUserName(user)) {
@ -241,25 +243,39 @@ static void asyncConnCallback(void *param, TAOS_RES *tres, int code) {
 }

 TAOS *taos_connect_a(char *ip, char *user, char *pass, char *db, uint16_t port, void (*fp)(void *, TAOS_RES *, int),
-                     void *param, void **taos) {
-  SSqlObj* pSql = taosConnectImpl(ip, user, pass, NULL, db, port, asyncConnCallback, param, taos);
+                     void *param, TAOS **taos) {
+  STscObj *pObj = NULL;
+  SSqlObj *pSql = taosConnectImpl(ip, user, pass, NULL, db, port, asyncConnCallback, param, (void **)&pObj);
  if (pSql == NULL) {
    return NULL;
  }

+  if (taos) *taos = pObj;
+
  pSql->fetchFp = fp;
  pSql->res.code = tscProcessSql(pSql);
  tscDebug("%p DB async connection is opening", taos);
-  return taos;
+  return pObj;
 }

 void taos_close(TAOS *taos) {
  STscObj *pObj = (STscObj *)taos;

-  if (pObj == NULL || pObj->signature != pObj)  {
+  if (pObj == NULL) {
+    tscDebug("(null) try to free tscObj and close dnodeConn");
    return;
  }

+  tscDebug("%p try to free tscObj and close dnodeConn:%p", pObj, pObj->pDnodeConn);
+  if (pObj->signature != pObj) {
+    tscDebug("%p already closed or invalid tscObj", pObj);
+    return;
+  }
+
+  // make sure that the close connection can only be executed once.
+  pObj->signature = NULL;
+  taosTmrStopA(&(pObj->pTimer));
+
  SSqlObj* pHb = pObj->pHb;
  if (pHb != NULL && atomic_val_compare_exchange_ptr(&pObj->pHb, pHb, 0) == pHb) {
    if (pHb->pRpcCtx != NULL) {  // wait for rsp from dnode
@ -295,7 +311,7 @@ static void waitForRetrieveRsp(void *param, TAOS_RES *tres, int numOfRows) {
  tsem_post(&pSql->rspSem);
 }

-TAOS_RES* taos_query_c(TAOS *taos, const char *sqlstr, uint32_t sqlLen) {
+TAOS_RES* taos_query_c(TAOS *taos, const char *sqlstr, uint32_t sqlLen, TAOS_RES** res) {
  STscObj *pObj = (STscObj *)taos;
  if (pObj == NULL || pObj->signature != pObj) {
    terrno = TSDB_CODE_TSC_DISCONNECTED;
@ -320,12 +336,20 @@ TAOS_RES* taos_query_c(TAOS *taos, const char *sqlstr, uint32_t sqlLen) {
  tsem_init(&pSql->rspSem, 0, 0);
  doAsyncQuery(pObj, pSql, waitForQueryRsp, taos, sqlstr, sqlLen);

+  if (res != NULL) {
+    *res = pSql;
+  }
+
  tsem_wait(&pSql->rspSem);
  return pSql; 
 }

 TAOS_RES* taos_query(TAOS *taos, const char *sqlstr) {
-  return taos_query_c(taos, sqlstr, (uint32_t)strlen(sqlstr));
+  return taos_query_c(taos, sqlstr, (uint32_t)strlen(sqlstr), NULL);
+}
+
+TAOS_RES* taos_query_h(TAOS* taos, const char *sqlstr, TAOS_RES** res) {
+  return taos_query_c(taos, sqlstr, (uint32_t) strlen(sqlstr), res);
 }

 int taos_result_precision(TAOS_RES *res) {
@ -349,7 +373,7 @@ int taos_num_fields(TAOS_RES *res) {

  size_t numOfCols = tscNumOfFields(pQueryInfo);
  for(int32_t i = 0; i < numOfCols; ++i) {
-    SFieldSupInfo* pInfo = taosArrayGet(pQueryInfo->fieldsInfo.pSupportInfo, i);
+    SInternalField* pInfo = taosArrayGet(pQueryInfo->fieldsInfo.internalField, i);
    if (pInfo->visible) {
      num++;
    }
@ -386,7 +410,23 @@ TAOS_FIELD *taos_fetch_fields(TAOS_RES *res) {
    return NULL;
  }

-  return pQueryInfo->fieldsInfo.pFields->pData;
+  SFieldInfo *pFieldInfo = &pQueryInfo->fieldsInfo;
+
+  if (pFieldInfo->final == NULL) {
+    TAOS_FIELD* f = calloc(pFieldInfo->numOfOutput, sizeof(TAOS_FIELD));
+
+    int32_t j = 0;
+    for(int32_t i = 0; i < pFieldInfo->numOfOutput; ++i) {
+      SInternalField* pField = tscFieldInfoGetInternalField(pFieldInfo, i);
+      if (pField->visible) {
+        f[j++] = pField->field;
+      }
+    }
+
+    pFieldInfo->final = f;
+  }
+
+  return pFieldInfo->final;
 }

 int taos_retrieve(TAOS_RES *res) {
@ -459,6 +499,7 @@ TAOS_ROW taos_fetch_row(TAOS_RES *res) {
  SSqlRes *pRes = &pSql->res;
  
  if (pRes->qhandle == 0 ||
+      pRes->code == TSDB_CODE_TSC_QUERY_CANCELLED ||
      pCmd->command == TSDB_SQL_RETRIEVE_EMPTY_RESULT ||
      pCmd->command == TSDB_SQL_INSERT) {
    return NULL;
@ -522,7 +563,7 @@ int taos_fetch_block(TAOS_RES *res, TAOS_ROW *rows) {
    pRes->numOfClauseTotal = 0;
    pRes->rspType = 0;

-    pSql->numOfSubs = 0;
+    pSql->subState.numOfSub = 0;
    taosTFree(pSql->pSubs);

    assert(pSql->fp == NULL);
@ -566,7 +607,8 @@ static UNUSED_FUNC bool tscKillQueryInDnode(SSqlObj* pSql) {
    return true;
  }

-  SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, 0);
+  SQueryInfo *pQueryInfo = tscGetQueryInfoDetail(pCmd, 0);
+
  if ((pQueryInfo == NULL) || tscIsTwoStageSTableQuery(pQueryInfo, 0)) {
    return true;
  }
@ -676,6 +718,46 @@ int* taos_fetch_lengths(TAOS_RES *res) {

 char *taos_get_client_info() { return version; }

+static void tscKillSTableQuery(SSqlObj *pSql) {
+  SSqlCmd* pCmd = &pSql->cmd;
+
+  SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);
+
+  if (!tscIsTwoStageSTableQuery(pQueryInfo, 0)) {
+    return;
+  }
+
+  // set the master sqlObj flag to cancel query
+  pSql->res.code = TSDB_CODE_TSC_QUERY_CANCELLED;
+
+  for (int i = 0; i < pSql->subState.numOfSub; ++i) {
+    // NOTE: pSub may have been released already here
+    SSqlObj *pSub = pSql->pSubs[i];
+    if (pSub == NULL) {
+      continue;
+    }
+
+    void** p = taosCacheAcquireByKey(tscObjCache, &pSub, sizeof(TSDB_CACHE_PTR_TYPE));
+    if (p == NULL) {
+      continue;
+    }
+
+    SSqlObj* pSubObj = (SSqlObj*) (*p);
+    assert(pSubObj->self == (SSqlObj**) p);
+
+    pSubObj->res.code = TSDB_CODE_TSC_QUERY_CANCELLED;
+    if (pSubObj->pRpcCtx != NULL) {
+      rpcCancelRequest(pSubObj->pRpcCtx);
+      pSubObj->pRpcCtx = NULL;
+    }
+
+    tscQueueAsyncRes(pSubObj);
+    taosCacheRelease(tscObjCache, (void**) &p, false);
+  }
+
+  tscDebug("%p super table query cancelled", pSql);
+}
+
 void taos_stop_query(TAOS_RES *res) {
  SSqlObj *pSql = (SSqlObj *)res;
  if (pSql == NULL || pSql->signature != pSql) {
@ -685,23 +767,27 @@ void taos_stop_query(TAOS_RES *res) {
  tscDebug("%p start to cancel query", res);
  SSqlCmd *pCmd = &pSql->cmd;

-  // TODO there are multi-thread problem.
-  // It may have been released by the other thread already.
-  // The ref count may fix this problem.
-  SQueryInfo *pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);
-
  // set the error code for master pSqlObj firstly
  pSql->res.code = TSDB_CODE_TSC_QUERY_CANCELLED;

+  SQueryInfo *pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);
+
  if (tscIsTwoStageSTableQuery(pQueryInfo, 0)) {
    assert(pSql->pRpcCtx == NULL);
    tscKillSTableQuery(pSql);
  } else {
    if (pSql->cmd.command < TSDB_SQL_LOCAL) {
+      /*
+       * There is multi-thread problem here, since pSql->pRpcCtx may have been
+       * reset and freed in the processMsgFromServer function, and causes the invalid
+       * write problem for rpcCancelRequest.
+       */
      if (pSql->pRpcCtx != NULL) {
        rpcCancelRequest(pSql->pRpcCtx);
        pSql->pRpcCtx = NULL;
      }
+
+      tscQueueAsyncRes(pSql);
    }
  }

@ -814,7 +900,7 @@ int taos_validate_sql(TAOS *taos, const char *sql) {
  if (pSql->sqlstr == NULL) {
    pRes->code = TSDB_CODE_TSC_OUT_OF_MEMORY;
    tscError("%p failed to malloc sql string buffer", pSql);
-    tscDebug("%p Valid SQL result:%d, %s pObj:%p", pSql, pRes->code, taos_errstr(taos), pObj);
+    tscDebug("%p Valid SQL result:%d, %s pObj:%p", pSql, pRes->code, taos_errstr(pSql), pObj);
    taosTFree(pSql);
    return pRes->code;
  }
@ -830,6 +916,8 @@ int taos_validate_sql(TAOS *taos, const char *sql) {
  pSql->fp = asyncCallback;
  pSql->fetchFp = asyncCallback;
  pSql->param = pSql;
+
+  registerSqlObj(pSql);
  int code = tsParseSql(pSql, true);
  if (code == TSDB_CODE_TSC_ACTION_IN_PROGRESS) {
    tsem_wait(&pSql->rspSem);
@ -837,7 +925,7 @@ int taos_validate_sql(TAOS *taos, const char *sql) {
  }

  if (code != TSDB_CODE_SUCCESS) {
-    tscDebug("%p Valid SQL result:%d, %s pObj:%p", pSql, code, taos_errstr(taos), pObj);
+    tscDebug("%p Valid SQL result:%d, %s pObj:%p", pSql, code, taos_errstr(pSql), pObj);
  }

  taos_free_result(pSql);
@ -981,7 +1069,7 @@ int taos_load_table_info(TAOS *taos, const char *tableNameList) {

  tscDoQuery(pSql);

-  tscDebug("%p load multi table meta result:%d %s pObj:%p", pSql, pRes->code, taos_errstr(taos), pObj);
+  tscDebug("%p load multi table meta result:%d %s pObj:%p", pSql, pRes->code, taos_errstr(pSql), pObj);
  if ((code = pRes->code) != TSDB_CODE_SUCCESS) {
    tscFreeSqlObj(pSql);
  }
--- a/src/client/src/tscStream.c
+++ b/src/client/src/tscStream.c
@ -168,7 +168,7 @@ static void tscProcessStreamQueryCallback(void *param, TAOS_RES *tres, int numOf

    STableMetaInfo* pTableMetaInfo = tscGetTableMetaInfoFromCmd(&pStream->pSql->cmd, 0, 0);
    taosCacheRelease(tscMetaCache, (void**)&(pTableMetaInfo->pTableMeta), true);
-    taosTFree(pTableMetaInfo->vgroupList);
+    pTableMetaInfo->vgroupList = tscVgroupInfoClear(pTableMetaInfo->vgroupList);

    tscSetRetryTimer(pStream, pStream->pSql, retryDelay);
    return;
@ -274,8 +274,8 @@ static void tscProcessStreamRetrieveResult(void *param, TAOS_RES *res, int numOf
    taosCacheRelease(tscMetaCache, (void**)&(pTableMetaInfo->pTableMeta), false);
    tscFreeSqlResult(pSql);
    taosTFree(pSql->pSubs);
-    pSql->numOfSubs = 0;
-    taosTFree(pTableMetaInfo->vgroupList);
+    pSql->subState.numOfSub = 0;
+    pTableMetaInfo->vgroupList = tscVgroupInfoClear(pTableMetaInfo->vgroupList);
    tscSetNextLaunchTimer(pStream, pSql);
  }
 }
--- a/src/client/src/tscSubquery.c
+++ b/src/client/src/tscSubquery.c
@ -26,7 +26,6 @@
 #include "tscSubquery.h"

 typedef struct SInsertSupporter {
-  SSubqueryState* pState;
  SSqlObj*  pSql;
  int32_t   index;
 } SInsertSupporter;
@ -167,14 +166,13 @@ static int64_t doTSBlockIntersect(SSqlObj* pSql, SJoinSupporter* pSupporter1, SJ
 }

 // todo handle failed to create sub query
-SJoinSupporter* tscCreateJoinSupporter(SSqlObj* pSql, SSubqueryState* pState, int32_t index) {
+SJoinSupporter* tscCreateJoinSupporter(SSqlObj* pSql, int32_t index) {
  SJoinSupporter* pSupporter = calloc(1, sizeof(SJoinSupporter));
  if (pSupporter == NULL) {
    return NULL;
  }

  pSupporter->pObj = pSql;
-  pSupporter->pState = pState;

  pSupporter->subqueryIndex = index;
  SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(&pSql->cmd, pSql->cmd.clauseIndex);
@ -250,7 +248,7 @@ static int32_t tscLaunchRealSubqueries(SSqlObj* pSql) {
  SJoinSupporter* pSupporter = NULL;
  
  //If the columns are not involved in the final select clause, the corresponding query will not be issued.
-  for (int32_t i = 0; i < pSql->numOfSubs; ++i) {
+  for (int32_t i = 0; i < pSql->subState.numOfSub; ++i) {
    pSupporter = pSql->pSubs[i]->param;
    if (taosArrayGetSize(pSupporter->exprList) > 0) {
      ++numOfSub;
@ -260,16 +258,15 @@ static int32_t tscLaunchRealSubqueries(SSqlObj* pSql) {
  assert(numOfSub > 0);
  
  // scan all subquery, if one sub query has only ts, ignore it
-  tscDebug("%p start to launch secondary subqueries, total:%d, only:%d needs to query", pSql, pSql->numOfSubs, numOfSub);
+  tscDebug("%p start to launch secondary subqueries, %d out of %d needs to query", pSql, numOfSub, pSql->subState.numOfSub);

  //the subqueries that do not actually launch the secondary query to virtual node is set as completed.
-  SSubqueryState* pState = pSupporter->pState;
-  pState->numOfTotal = pSql->numOfSubs;
+  SSubqueryState* pState = &pSql->subState;
  pState->numOfRemain = numOfSub;

  bool success = true;
  
-  for (int32_t i = 0; i < pSql->numOfSubs; ++i) {
+  for (int32_t i = 0; i < pSql->subState.numOfSub; ++i) {
    SSqlObj *pPrevSub = pSql->pSubs[i];
    pSql->pSubs[i] = NULL;
    
@ -322,7 +319,7 @@ static int32_t tscLaunchRealSubqueries(SSqlObj* pSql) {
    memset(&pSupporter->fieldsInfo, 0, sizeof(SFieldInfo));
  
    SQueryInfo *pNewQueryInfo = tscGetQueryInfoDetail(&pNew->cmd, 0);
-    assert(pNew->numOfSubs == 0 && pNew->cmd.numOfClause == 1 && pNewQueryInfo->numOfTables == 1);
+    assert(pNew->subState.numOfSub == 0 && pNew->cmd.numOfClause == 1 && pNewQueryInfo->numOfTables == 1);
  
    tscFieldInfoUpdateOffset(pNewQueryInfo);
  
@ -373,13 +370,13 @@ static int32_t tscLaunchRealSubqueries(SSqlObj* pSql) {
  if (!success) {
    pSql->res.code = TSDB_CODE_TSC_OUT_OF_MEMORY;
    tscError("%p failed to prepare subqueries objs for secondary phase query, numOfSub:%d, code:%d", pSql,
-        pSql->numOfSubs, pSql->res.code);
+        pSql->subState.numOfSub, pSql->res.code);
    freeJoinSubqueryObj(pSql);
    
    return pSql->res.code;
  }
  
-  for(int32_t i = 0; i < pSql->numOfSubs; ++i) {
+  for(int32_t i = 0; i < pSql->subState.numOfSub; ++i) {
    if (pSql->pSubs[i] == NULL) {
      continue;
    }
@ -391,17 +388,13 @@ static int32_t tscLaunchRealSubqueries(SSqlObj* pSql) {
 }

 void freeJoinSubqueryObj(SSqlObj* pSql) {
-  SSubqueryState* pState = NULL;
-
-  for (int32_t i = 0; i < pSql->numOfSubs; ++i) {
+  for (int32_t i = 0; i < pSql->subState.numOfSub; ++i) {
    SSqlObj* pSub = pSql->pSubs[i];
    if (pSub == NULL) {
      continue;
    }
    
    SJoinSupporter* p = pSub->param;
-    pState = p->pState;
-
    tscDestroyJoinSupporter(p);

    if (pSub->res.code == TSDB_CODE_SUCCESS) {
@ -409,14 +402,13 @@ void freeJoinSubqueryObj(SSqlObj* pSql) {
    }
  }

-  taosTFree(pState);
-  pSql->numOfSubs = 0;
+  pSql->subState.numOfSub = 0;
 }

 static void quitAllSubquery(SSqlObj* pSqlObj, SJoinSupporter* pSupporter) {
-  assert(pSupporter->pState->numOfRemain > 0);
+  assert(pSqlObj->subState.numOfRemain > 0);

-  if (atomic_sub_fetch_32(&pSupporter->pState->numOfRemain, 1) <= 0) {
+  if (atomic_sub_fetch_32(&pSqlObj->subState.numOfRemain, 1) <= 0) {
    tscError("%p all subquery return and query failed, global code:%d", pSqlObj, pSqlObj->res.code);
    freeJoinSubqueryObj(pSqlObj);
  }
@ -457,7 +449,7 @@ void tscBuildVgroupTableInfo(SSqlObj* pSql, STableMetaInfo* pTableMetaInfo, SArr
      SVgroupTableInfo info = {{0}};
      for (int32_t m = 0; m < pvg->numOfVgroups; ++m) {
        if (tt->vgId == pvg->vgroups[m].vgId) {
-          info.vgInfo = pvg->vgroups[m];
+          tscSCMVgroupInfoCopy(&info.vgInfo, &pvg->vgroups[m]);
          break;
        }
      }
@ -680,7 +672,7 @@ static void tidTagRetrieveCallback(void* param, TAOS_RES* tres, int32_t numOfRow

  // no data exists in next vnode, mark the <tid, tags> query completed
  // only when there is no subquery exits any more, proceeds to get the intersect of the <tid, tags> tuple sets.
-  if (atomic_sub_fetch_32(&pSupporter->pState->numOfRemain, 1) > 0) {
+  if (atomic_sub_fetch_32(&pParentSql->subState.numOfRemain, 1) > 0) {
    return;
  }

@ -716,10 +708,10 @@ static void tidTagRetrieveCallback(void* param, TAOS_RES* tres, int32_t numOfRow
    STableMetaInfo* pTableMetaInfo2 = tscGetMetaInfo(pQueryInfo2, 0);
    tscBuildVgroupTableInfo(pParentSql, pTableMetaInfo2, s2);

-    pSupporter->pState->numOfTotal = 2;
-    pSupporter->pState->numOfRemain = pSupporter->pState->numOfTotal;
+    pParentSql->subState.numOfSub = 2;
+    pParentSql->subState.numOfRemain = pParentSql->subState.numOfSub;

-    for (int32_t m = 0; m < pParentSql->numOfSubs; ++m) {
+    for (int32_t m = 0; m < pParentSql->subState.numOfSub; ++m) {
      SSqlObj* sub = pParentSql->pSubs[m];
      issueTSCompQuery(sub, sub->param, pParentSql);
    }
@ -818,7 +810,7 @@ static void tsCompRetrieveCallback(void* param, TAOS_RES* tres, int32_t numOfRow
    return;
  }

-  if (atomic_sub_fetch_32(&pSupporter->pState->numOfRemain, 1) > 0) {
+  if (atomic_sub_fetch_32(&pParentSql->subState.numOfRemain, 1) > 0) {
    return;
  }

@ -850,7 +842,6 @@ static void joinRetrieveFinalResCallback(void* param, TAOS_RES* tres, int numOfR
  SJoinSupporter* pSupporter = (SJoinSupporter*)param;

  SSqlObj* pParentSql = pSupporter->pObj;
-  SSubqueryState* pState = pSupporter->pState;

  SSqlObj* pSql = (SSqlObj*)tres;
  SSqlCmd* pCmd = &pSql->cmd;
@ -871,6 +862,7 @@ static void joinRetrieveFinalResCallback(void* param, TAOS_RES* tres, int numOfR
    pRes->numOfTotal += pRes->numOfRows;
  }

+  SSubqueryState* pState = &pParentSql->subState;
  if (tscNonOrderedProjectionQueryOnSTable(pQueryInfo, 0) && numOfRows == 0) {
    STableMetaInfo* pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
    assert(pQueryInfo->numOfTables == 1);
@ -878,7 +870,7 @@ static void joinRetrieveFinalResCallback(void* param, TAOS_RES* tres, int numOfR
    // for projection query, need to try next vnode if current vnode is exhausted
    if ((++pTableMetaInfo->vgroupIndex) < pTableMetaInfo->vgroupList->numOfVgroups) {
      pState->numOfRemain = 1;
-      pState->numOfTotal = 1;
+      pState->numOfSub = 1;

      pSql->cmd.command = TSDB_SQL_SELECT;
      pSql->fp = tscJoinQueryCallback;
@ -888,12 +880,12 @@ static void joinRetrieveFinalResCallback(void* param, TAOS_RES* tres, int numOfR
    }
  }

-  if (atomic_sub_fetch_32(&pState->numOfRemain, 1) > 0) {
-    tscDebug("%p sub:%p completed, remain:%d, total:%d", pParentSql, tres, pState->numOfRemain, pState->numOfTotal);
+  if (atomic_sub_fetch_32(&pParentSql->subState.numOfRemain, 1) > 0) {
+    tscDebug("%p sub:%p completed, remain:%d, total:%d", pParentSql, tres, pParentSql->subState.numOfRemain, pState->numOfSub);
    return;
  }

-  tscDebug("%p all %d secondary subqueries retrieval completed, code:%d", tres, pState->numOfTotal, pParentSql->res.code);
+  tscDebug("%p all %d secondary subqueries retrieval completed, code:%d", tres, pState->numOfSub, pParentSql->res.code);

  if (pParentSql->res.code != TSDB_CODE_SUCCESS) {
    freeJoinSubqueryObj(pParentSql);
@ -901,7 +893,7 @@ static void joinRetrieveFinalResCallback(void* param, TAOS_RES* tres, int numOfR
  }

  // update the records for each subquery in parent sql object.
-  for (int32_t i = 0; i < pParentSql->numOfSubs; ++i) {
+  for (int32_t i = 0; i < pState->numOfSub; ++i) {
    if (pParentSql->pSubs[i] == NULL) {
      continue;
    }
@ -917,32 +909,26 @@ static void joinRetrieveFinalResCallback(void* param, TAOS_RES* tres, int numOfR
 static SJoinSupporter* tscUpdateSubqueryStatus(SSqlObj* pSql, int32_t numOfFetch) {
  int32_t notInvolved = 0;
  SJoinSupporter* pSupporter = NULL;
-  SSubqueryState* pState = NULL;
+  SSubqueryState* pState = &pSql->subState;
  
-  for(int32_t i = 0; i < pSql->numOfSubs; ++i) {
+  for(int32_t i = 0; i < pSql->subState.numOfSub; ++i) {
    if (pSql->pSubs[i] == NULL) {
      notInvolved++;
    } else {
      pSupporter = (SJoinSupporter*)pSql->pSubs[i]->param;
-      pState = pSupporter->pState;
    }
  }
  
-  assert(pState != NULL);
-  if (pState != NULL) {
-    pState->numOfTotal = pSql->numOfSubs;
-    pState->numOfRemain = numOfFetch;
-  }
-  
+  pState->numOfRemain = numOfFetch;
  return pSupporter;
 }

 void tscFetchDatablockFromSubquery(SSqlObj* pSql) {
-  assert(pSql->numOfSubs >= 1);
+  assert(pSql->subState.numOfSub >= 1);
  
  int32_t numOfFetch = 0;
  bool hasData = true;
-  for (int32_t i = 0; i < pSql->numOfSubs; ++i) {
+  for (int32_t i = 0; i < pSql->subState.numOfSub; ++i) {
    // if the subquery is NULL, it does not involved in the final result generation
    SSqlObj* pSub = pSql->pSubs[i];
    if (pSub == NULL) {
@ -989,7 +975,7 @@ void tscFetchDatablockFromSubquery(SSqlObj* pSql) {
  tscDebug("%p retrieve data from %d subqueries", pSql, numOfFetch);
  SJoinSupporter* pSupporter = tscUpdateSubqueryStatus(pSql, numOfFetch);
  
-  for (int32_t i = 0; i < pSql->numOfSubs; ++i) {
+  for (int32_t i = 0; i < pSql->subState.numOfSub; ++i) {
    SSqlObj* pSql1 = pSql->pSubs[i];
    if (pSql1 == NULL) {
      continue;
@ -1124,7 +1110,7 @@ void tscJoinQueryCallback(void* param, TAOS_RES* tres, int code) {
  }

  // wait for the other subqueries response from vnode
-  if (atomic_sub_fetch_32(&pSupporter->pState->numOfRemain, 1) > 0) {
+  if (atomic_sub_fetch_32(&pParentSql->subState.numOfRemain, 1) > 0) {
    return;
  }

@ -1136,7 +1122,7 @@ void tscJoinQueryCallback(void* param, TAOS_RES* tres, int code) {
   * data instead of returning to its invoker
   */
  if (pTableMetaInfo->vgroupIndex > 0 && tscNonOrderedProjectionQueryOnSTable(pQueryInfo, 0)) {
-    pSupporter->pState->numOfRemain = pSupporter->pState->numOfTotal;  // reset the record value
+    pParentSql->subState.numOfRemain = pParentSql->subState.numOfSub;  // reset the record value

    pSql->fp = joinRetrieveFinalResCallback;  // continue retrieve data
    pSql->cmd.command = TSDB_SQL_FETCH;
@ -1156,7 +1142,6 @@ static void tscRetrieveDataRes(void *param, TAOS_RES *tres, int code);

 static SSqlObj *tscCreateSTableSubquery(SSqlObj *pSql, SRetrieveSupport *trsupport, SSqlObj *prevSqlObj);

-// TODO
 int32_t tscCreateJoinSubquery(SSqlObj *pSql, int16_t tableIndex, SJoinSupporter *pSupporter) {
  SSqlCmd *   pCmd = &pSql->cmd;
  SQueryInfo *pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);
@ -1165,7 +1150,7 @@ int32_t tscCreateJoinSubquery(SSqlObj *pSql, int16_t tableIndex, SJoinSupporter
  assert(pSql->res.numOfRows == 0);

  if (pSql->pSubs == NULL) {
-    pSql->pSubs = calloc(pSupporter->pState->numOfTotal, POINTER_BYTES);
+    pSql->pSubs = calloc(pSql->subState.numOfSub, POINTER_BYTES);
    if (pSql->pSubs == NULL) {
      return TSDB_CODE_TSC_OUT_OF_MEMORY;
    }
@ -1176,8 +1161,8 @@ int32_t tscCreateJoinSubquery(SSqlObj *pSql, int16_t tableIndex, SJoinSupporter
    return TSDB_CODE_TSC_OUT_OF_MEMORY;
  }
  
-  pSql->pSubs[pSql->numOfSubs++] = pNew;
-  assert(pSql->numOfSubs <= pSupporter->pState->numOfTotal);
+  pSql->pSubs[pSql->subState.numOfRemain++] = pNew;
+  assert(pSql->subState.numOfRemain <= pSql->subState.numOfSub);
  
  if (QUERY_IS_JOIN_QUERY(pQueryInfo->type)) {
    addGroupInfoForSubquery(pSql, pNew, 0, tableIndex);
@ -1221,7 +1206,7 @@ int32_t tscCreateJoinSubquery(SSqlObj *pSql, int16_t tableIndex, SJoinSupporter
    STableMetaInfo *pTableMetaInfo = tscGetMetaInfo(pNewQueryInfo, 0);
    
    if (UTIL_TABLE_IS_SUPER_TABLE(pTableMetaInfo)) { // return the tableId & tag
-      SColumnIndex index = {0};
+      SColumnIndex colIndex = {0};

      STagCond* pTagCond = &pSupporter->tagCond;
      assert(pTagCond->joinInfo.hasJoin);
@ -1234,7 +1219,7 @@ int32_t tscCreateJoinSubquery(SSqlObj *pSql, int16_t tableIndex, SJoinSupporter
      SSchema* pSchema = tscGetTableTagSchema(pTableMetaInfo->pTableMeta);
      for(int32_t i = 0; i < numOfTags; ++i) {
        if (pSchema[i].colId == tagColId) {
-          index.columnIndex = i;
+          colIndex.columnIndex = i;
          break;
        }
      }
@ -1251,18 +1236,18 @@ int32_t tscCreateJoinSubquery(SSqlObj *pSql, int16_t tableIndex, SJoinSupporter

      // set get tags query type
      TSDB_QUERY_SET_TYPE(pNewQueryInfo->type, TSDB_QUERY_TYPE_TAG_FILTER_QUERY);
-      tscAddSpecialColumnForSelect(pNewQueryInfo, 0, TSDB_FUNC_TID_TAG, &index, &s1, TSDB_COL_TAG);
+      tscAddSpecialColumnForSelect(pNewQueryInfo, 0, TSDB_FUNC_TID_TAG, &colIndex, &s1, TSDB_COL_TAG);
      size_t numOfCols = taosArrayGetSize(pNewQueryInfo->colList);
  
      tscDebug(
          "%p subquery:%p tableIndex:%d, vgroupIndex:%d, type:%d, transfer to tid_tag query to retrieve (tableId, tags), "
          "exprInfo:%" PRIzu ", colList:%" PRIzu ", fieldsInfo:%d, tagIndex:%d, name:%s",
          pSql, pNew, tableIndex, pTableMetaInfo->vgroupIndex, pNewQueryInfo->type, tscSqlExprNumOfExprs(pNewQueryInfo),
-          numOfCols, pNewQueryInfo->fieldsInfo.numOfOutput, index.columnIndex, pNewQueryInfo->pTableMetaInfo[0]->name);
+          numOfCols, pNewQueryInfo->fieldsInfo.numOfOutput, colIndex.columnIndex, pNewQueryInfo->pTableMetaInfo[0]->name);
    } else {
      SSchema      colSchema = {.type = TSDB_DATA_TYPE_BINARY, .bytes = 1};
-      SColumnIndex index = {0, PRIMARYKEY_TIMESTAMP_COL_INDEX};
-      tscAddSpecialColumnForSelect(pNewQueryInfo, 0, TSDB_FUNC_TS_COMP, &index, &colSchema, TSDB_COL_NORMAL);
+      SColumnIndex colIndex = {0, PRIMARYKEY_TIMESTAMP_COL_INDEX};
+      tscAddSpecialColumnForSelect(pNewQueryInfo, 0, TSDB_FUNC_TS_COMP, &colIndex, &colSchema, TSDB_COL_NORMAL);

      // set the tags value for ts_comp function
      SSqlExpr *pExpr = tscSqlExprGet(pNewQueryInfo, 0);
@ -1312,22 +1297,13 @@ void tscHandleMasterJoinQuery(SSqlObj* pSql) {
  assert((pQueryInfo->type & TSDB_QUERY_TYPE_SUBQUERY) == 0);

  int32_t code = TSDB_CODE_SUCCESS;
-
-  // todo add test
-  SSubqueryState *pState = calloc(1, sizeof(SSubqueryState));
-  if (pState == NULL) {
-    code = TSDB_CODE_TSC_OUT_OF_MEMORY;
-    goto _error;
-  }
-
-  pState->numOfTotal = pQueryInfo->numOfTables;
-  pState->numOfRemain = pState->numOfTotal;
+  pSql->subState.numOfSub = pQueryInfo->numOfTables;

  bool hasEmptySub = false;

  tscDebug("%p start subquery, total:%d", pSql, pQueryInfo->numOfTables);
  for (int32_t i = 0; i < pQueryInfo->numOfTables; ++i) {
-    SJoinSupporter *pSupporter = tscCreateJoinSupporter(pSql, pState, i);
+    SJoinSupporter *pSupporter = tscCreateJoinSupporter(pSql, i);
    
    if (pSupporter == NULL) {  // failed to create support struct, abort current query
      tscError("%p tableIndex:%d, failed to allocate join support object, abort further query", pSql, i);
@ -1354,10 +1330,10 @@ void tscHandleMasterJoinQuery(SSqlObj* pSql) {
    pSql->cmd.command = TSDB_SQL_RETRIEVE_EMPTY_RESULT;
    (*pSql->fp)(pSql->param, pSql, 0);
  } else {
-    for (int32_t i = 0; i < pSql->numOfSubs; ++i) {
+    for (int32_t i = 0; i < pSql->subState.numOfSub; ++i) {
      SSqlObj* pSub = pSql->pSubs[i];
      if ((code = tscProcessSql(pSub)) != TSDB_CODE_SUCCESS) {
-        pState->numOfRemain = i - 1;  // the already sent reques will continue and do not go to the error process routine
+        pSql->subState.numOfRemain = i - 1;  // the already sent request will continue and do not go to the error process routine
        break;
      }
    }
@ -1372,8 +1348,8 @@ void tscHandleMasterJoinQuery(SSqlObj* pSql) {
  tscQueueAsyncRes(pSql);
 }

-static void doCleanupSubqueries(SSqlObj *pSql, int32_t numOfSubs, SSubqueryState* pState) {
-  assert(numOfSubs <= pSql->numOfSubs && numOfSubs >= 0 && pState != NULL);
+static void doCleanupSubqueries(SSqlObj *pSql, int32_t numOfSubs) {
+  assert(numOfSubs <= pSql->subState.numOfSub && numOfSubs >= 0);
  
  for(int32_t i = 0; i < numOfSubs; ++i) {
    SSqlObj* pSub = pSql->pSubs[i];
@ -1386,8 +1362,6 @@ static void doCleanupSubqueries(SSqlObj *pSql, int32_t numOfSubs, SSubqueryState
    
    taos_free_result(pSub);
  }
-  
-  free(pState);
 }

 int32_t tscHandleMasterSTableQuery(SSqlObj *pSql) {
@ -1410,9 +1384,10 @@ int32_t tscHandleMasterSTableQuery(SSqlObj *pSql) {
  
  SQueryInfo     *pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);
  STableMetaInfo *pTableMetaInfo = tscGetMetaInfo(pQueryInfo, 0);
+  SSubqueryState *pState = &pSql->subState;

-  pSql->numOfSubs = pTableMetaInfo->vgroupList->numOfVgroups;
-  assert(pSql->numOfSubs > 0);
+  pState->numOfSub = pTableMetaInfo->vgroupList->numOfVgroups;
+  assert(pState->numOfSub > 0);
  
  int32_t ret = tscLocalReducerEnvCreate(pSql, &pMemoryBuf, &pDesc, &pModel, nBufferSize);
  if (ret != 0) {
@ -1422,28 +1397,24 @@ int32_t tscHandleMasterSTableQuery(SSqlObj *pSql) {
    return ret;
  }
  
-  pSql->pSubs = calloc(pSql->numOfSubs, POINTER_BYTES);
+  pSql->pSubs = calloc(pState->numOfSub, POINTER_BYTES);

-  tscDebug("%p retrieved query data from %d vnode(s)", pSql, pSql->numOfSubs);
-  SSubqueryState *pState = calloc(1, sizeof(SSubqueryState));
+  tscDebug("%p retrieved query data from %d vnode(s)", pSql, pState->numOfSub);

-  if (pSql->pSubs == NULL || pState == NULL) {
-    taosTFree(pState);
+  if (pSql->pSubs == NULL) {
    taosTFree(pSql->pSubs);
    pRes->code = TSDB_CODE_TSC_OUT_OF_MEMORY;
-    tscLocalReducerEnvDestroy(pMemoryBuf, pDesc, pModel, pSql->numOfSubs);
+    tscLocalReducerEnvDestroy(pMemoryBuf, pDesc, pModel, pState->numOfSub);

    tscQueueAsyncRes(pSql);
    return ret;
  }

-  pState->numOfTotal = pSql->numOfSubs;
-  pState->numOfRemain = pSql->numOfSubs;
-
+  pState->numOfRemain = pState->numOfSub;
  pRes->code = TSDB_CODE_SUCCESS;
  
  int32_t i = 0;
-  for (; i < pSql->numOfSubs; ++i) {
+  for (; i < pState->numOfSub; ++i) {
    SRetrieveSupport *trs = (SRetrieveSupport *)calloc(1, sizeof(SRetrieveSupport));
    if (trs == NULL) {
      tscError("%p failed to malloc buffer for SRetrieveSupport, orderOfSub:%d, reason:%s", pSql, i, strerror(errno));
@ -1452,7 +1423,6 @@ int32_t tscHandleMasterSTableQuery(SSqlObj *pSql) {
    
    trs->pExtMemBuffer = pMemoryBuf;
    trs->pOrderDescriptor = pDesc;
-    trs->pState = pState;

    trs->localBuffer = (tFilePage *)calloc(1, nBufferSize + sizeof(tFilePage));
    if (trs->localBuffer == NULL) {
@ -1461,8 +1431,8 @@ int32_t tscHandleMasterSTableQuery(SSqlObj *pSql) {
      break;
    }
    
-    trs->subqueryIndex = i;
-    trs->pParentSql = pSql;
+    trs->subqueryIndex  = i;
+    trs->pParentSql     = pSql;
    trs->pFinalColModel = pModel;
    
    SSqlObj *pNew = tscCreateSTableSubquery(pSql, trs, NULL);
@ -1483,22 +1453,22 @@ int32_t tscHandleMasterSTableQuery(SSqlObj *pSql) {
    tscDebug("%p sub:%p create subquery success. orderOfSub:%d", pSql, pNew, trs->subqueryIndex);
  }
  
-  if (i < pSql->numOfSubs) {
+  if (i < pState->numOfSub) {
    tscError("%p failed to prepare subquery structure and launch subqueries", pSql);
    pRes->code = TSDB_CODE_TSC_OUT_OF_MEMORY;
    
-    tscLocalReducerEnvDestroy(pMemoryBuf, pDesc, pModel, pSql->numOfSubs);
-    doCleanupSubqueries(pSql, i, pState);
+    tscLocalReducerEnvDestroy(pMemoryBuf, pDesc, pModel, pState->numOfSub);
+    doCleanupSubqueries(pSql, i);
    return pRes->code;   // free all allocated resource
  }
  
  if (pRes->code == TSDB_CODE_TSC_QUERY_CANCELLED) {
-    tscLocalReducerEnvDestroy(pMemoryBuf, pDesc, pModel, pSql->numOfSubs);
-    doCleanupSubqueries(pSql, i, pState);
+    tscLocalReducerEnvDestroy(pMemoryBuf, pDesc, pModel, pState->numOfSub);
+    doCleanupSubqueries(pSql, i);
    return pRes->code;
  }
  
-  for(int32_t j = 0; j < pSql->numOfSubs; ++j) {
+  for(int32_t j = 0; j < pState->numOfSub; ++j) {
    SSqlObj* pSub = pSql->pSubs[j];
    SRetrieveSupport* pSupport = pSub->param;
    
@ -1509,16 +1479,20 @@ int32_t tscHandleMasterSTableQuery(SSqlObj *pSql) {
  return TSDB_CODE_SUCCESS;
 }

-static void tscFreeSubSqlObj(SRetrieveSupport *trsupport, SSqlObj *pSql) {
-  tscDebug("%p start to free subquery obj", pSql);
+static void tscFreeRetrieveSup(SSqlObj *pSql) {
+  SRetrieveSupport *trsupport = pSql->param;

-  int32_t  index = trsupport->subqueryIndex;
-  SSqlObj *pParentSql = trsupport->pParentSql;
+  void* p = atomic_val_compare_exchange_ptr(&pSql->param, trsupport, 0);
+  if (p == NULL) {
+    tscDebug("%p retrieve supp already released", pSql);
+    return;
+  }

-  assert(pSql == pParentSql->pSubs[index]);
-//  pParentSql->pSubs[index] = NULL;
-//
-//  taos_free_result(pSql);
+  tscDebug("%p start to free subquery supp obj:%p", pSql, trsupport);
+//  int32_t  index = trsupport->subqueryIndex;
+//  SSqlObj *pParentSql = trsupport->pParentSql;
+
+//  assert(pSql == pParentSql->pSubs[index]);
  taosTFree(trsupport->localBuffer);
  taosTFree(trsupport);
 }
@ -1577,12 +1551,18 @@ static int32_t tscReissueSubquery(SRetrieveSupport *trsupport, SSqlObj *pSql, in
 }

 void tscHandleSubqueryError(SRetrieveSupport *trsupport, SSqlObj *pSql, int numOfRows) {
+  // it has been freed already
+  if (pSql->param != trsupport || pSql->param == NULL) {
+    return;
+  }
+
  SSqlObj *pParentSql = trsupport->pParentSql;
  int32_t  subqueryIndex = trsupport->subqueryIndex;
  
  assert(pSql != NULL);
-  SSubqueryState* pState = trsupport->pState;
-  assert(pState->numOfRemain <= pState->numOfTotal && pState->numOfRemain >= 0 && pParentSql->numOfSubs == pState->numOfTotal);
+
+  SSubqueryState* pState = &pParentSql->subState;
+  assert(pState->numOfRemain <= pState->numOfSub && pState->numOfRemain >= 0);

  // retrieved in subquery failed. OR query cancelled in retrieve phase.
  if (taos_errno(pSql) == TSDB_CODE_SUCCESS && pParentSql->res.code != TSDB_CODE_SUCCESS) {
@ -1616,22 +1596,21 @@ void tscHandleSubqueryError(SRetrieveSupport *trsupport, SSqlObj *pSql, int numO
  int32_t remain = -1;
  if ((remain = atomic_sub_fetch_32(&pState->numOfRemain, 1)) > 0) {
    tscDebug("%p sub:%p orderOfSub:%d freed, finished subqueries:%d", pParentSql, pSql, trsupport->subqueryIndex,
-        pState->numOfTotal - remain);
+        pState->numOfSub - remain);

-    tscFreeSubSqlObj(trsupport, pSql);
+    tscFreeRetrieveSup(pSql);
    return;
  }
  
  // all subqueries are failed
-  tscError("%p retrieve from %d vnode(s) completed,code:%s.FAILED.", pParentSql, pState->numOfTotal,
+  tscError("%p retrieve from %d vnode(s) completed,code:%s.FAILED.", pParentSql, pState->numOfSub,
      tstrerror(pParentSql->res.code));

  // release allocated resource
  tscLocalReducerEnvDestroy(trsupport->pExtMemBuffer, trsupport->pOrderDescriptor, trsupport->pFinalColModel,
-                            pState->numOfTotal);
+                            pState->numOfSub);
  
-  taosTFree(trsupport->pState);
-  tscFreeSubSqlObj(trsupport, pSql);
+  tscFreeRetrieveSup(pSql);

  // in case of second stage join subquery, invoke its callback function instead of regular QueueAsyncRes
  SQueryInfo *pQueryInfo = tscGetQueryInfoDetail(&pParentSql->cmd, 0);
@ -1650,16 +1629,16 @@ static void tscAllDataRetrievedFromDnode(SRetrieveSupport *trsupport, SSqlObj* p
  SSqlObj *         pParentSql = trsupport->pParentSql;
  tOrderDescriptor *pDesc = trsupport->pOrderDescriptor;
  
-  SSubqueryState* pState = trsupport->pState;
+  SSubqueryState* pState = &pParentSql->subState;
  SQueryInfo *pQueryInfo = tscGetQueryInfoDetail(&pSql->cmd, 0);
  
  STableMetaInfo* pTableMetaInfo = pQueryInfo->pTableMetaInfo[0];
  
  // data in from current vnode is stored in cache and disk
  uint32_t numOfRowsFromSubquery = (uint32_t)(trsupport->pExtMemBuffer[idx]->numOfTotalElems + trsupport->localBuffer->num);
-    tscDebug("%p sub:%p all data retrieved from ep:%s, vgId:%d, numOfRows:%d, orderOfSub:%d", pParentSql, pSql,
-        pTableMetaInfo->vgroupList->vgroups[0].epAddr[0].fqdn, pTableMetaInfo->vgroupList->vgroups[0].vgId,
-        numOfRowsFromSubquery, idx);
+  SVgroupsInfo* vgroupsInfo = pTableMetaInfo->vgroupList;
+  tscDebug("%p sub:%p all data retrieved from ep:%s, vgId:%d, numOfRows:%d, orderOfSub:%d", pParentSql, pSql,
+           vgroupsInfo->vgroups[0].epAddr[0].fqdn, vgroupsInfo->vgroups[0].vgId, numOfRowsFromSubquery, idx);
  
  tColModelCompact(pDesc->pColumnModel, trsupport->localBuffer, pDesc->pColumnModel->capacity);

@ -1687,11 +1666,11 @@ static void tscAllDataRetrievedFromDnode(SRetrieveSupport *trsupport, SSqlObj* p
  }
  
  int32_t remain = -1;
-  if ((remain = atomic_sub_fetch_32(&pState->numOfRemain, 1)) > 0) {
+  if ((remain = atomic_sub_fetch_32(&pParentSql->subState.numOfRemain, 1)) > 0) {
    tscDebug("%p sub:%p orderOfSub:%d freed, finished subqueries:%d", pParentSql, pSql, trsupport->subqueryIndex,
-        pState->numOfTotal - remain);
+        pState->numOfSub - remain);

-    tscFreeSubSqlObj(trsupport, pSql);
+    tscFreeRetrieveSup(pSql);
    return;
  }
  
@ -1699,21 +1678,19 @@ static void tscAllDataRetrievedFromDnode(SRetrieveSupport *trsupport, SSqlObj* p
  pDesc->pColumnModel->capacity = trsupport->pExtMemBuffer[idx]->numOfElemsPerPage;
  
  tscDebug("%p retrieve from %d vnodes completed.final NumOfRows:%" PRId64 ",start to build loser tree", pParentSql,
-           pState->numOfTotal, pState->numOfRetrievedRows);
+           pState->numOfSub, pState->numOfRetrievedRows);
  
  SQueryInfo *pPQueryInfo = tscGetQueryInfoDetail(&pParentSql->cmd, 0);
  tscClearInterpInfo(pPQueryInfo);
  
-  tscCreateLocalReducer(trsupport->pExtMemBuffer, pState->numOfTotal, pDesc, trsupport->pFinalColModel, pParentSql);
+  tscCreateLocalReducer(trsupport->pExtMemBuffer, pState->numOfSub, pDesc, trsupport->pFinalColModel, pParentSql);
  tscDebug("%p build loser tree completed", pParentSql);
  
  pParentSql->res.precision = pSql->res.precision;
  pParentSql->res.numOfRows = 0;
  pParentSql->res.row = 0;
  
-  // only free once
-  taosTFree(trsupport->pState);
-  tscFreeSubSqlObj(trsupport, pSql);
+  tscFreeRetrieveSup(pSql);

  // set the command flag must be after the semaphore been correctly set.
  pParentSql->cmd.command = TSDB_SQL_RETRIEVE_LOCALMERGE;
@ -1725,16 +1702,23 @@ static void tscAllDataRetrievedFromDnode(SRetrieveSupport *trsupport, SSqlObj* p
 }

 static void tscRetrieveFromDnodeCallBack(void *param, TAOS_RES *tres, int numOfRows) {
+  SSqlObj *pSql = (SSqlObj *)tres;
+  assert(pSql != NULL);
+
+  // this query has been freed already
  SRetrieveSupport *trsupport = (SRetrieveSupport *)param;
+  if (pSql->param == NULL || param == NULL) {
+    tscDebug("%p already freed in dnodecallback", pSql);
+    assert(pSql->res.code == TSDB_CODE_TSC_QUERY_CANCELLED);
+    return;
+  }
+
  tOrderDescriptor *pDesc = trsupport->pOrderDescriptor;
  int32_t           idx   = trsupport->subqueryIndex;
  SSqlObj *         pParentSql = trsupport->pParentSql;

-  assert(tres != NULL);
-  SSqlObj *pSql = (SSqlObj *)tres;
-
-  SSubqueryState* pState = trsupport->pState;
-  assert(pState->numOfRemain <= pState->numOfTotal && pState->numOfRemain >= 0 && pParentSql->numOfSubs == pState->numOfTotal);
+  SSubqueryState* pState = &pParentSql->subState;
+  assert(pState->numOfRemain <= pState->numOfSub && pState->numOfRemain >= 0);
  
  STableMetaInfo *pTableMetaInfo = tscGetTableMetaInfoFromCmd(&pSql->cmd, 0, 0);
  SCMVgroupInfo  *pVgroup = &pTableMetaInfo->vgroupList->vgroups[0];
@ -1751,6 +1735,10 @@ static void tscRetrieveFromDnodeCallBack(void *param, TAOS_RES *tres, int numOfR
  if (taos_errno(pSql) != TSDB_CODE_SUCCESS) {
    assert(numOfRows == taos_errno(pSql));

+    if (numOfRows == TSDB_CODE_TSC_QUERY_CANCELLED) {
+      trsupport->numOfRetry = MAX_NUM_OF_SUBQUERY_RETRY;
+    }
+
    if (trsupport->numOfRetry++ < MAX_NUM_OF_SUBQUERY_RETRY) {
      tscError("%p sub:%p failed code:%s, retry:%d", pParentSql, pSql, tstrerror(numOfRows), trsupport->numOfRetry);

@ -1822,7 +1810,7 @@ static SSqlObj *tscCreateSTableSubquery(SSqlObj *pSql, SRetrieveSupport *trsuppo
    SQueryInfo *pQueryInfo = tscGetQueryInfoDetail(&pNew->cmd, 0);

    pQueryInfo->type |= TSDB_QUERY_TYPE_STABLE_SUBQUERY;
-    assert(pQueryInfo->numOfTables == 1 && pNew->cmd.numOfClause == 1 && trsupport->subqueryIndex < pSql->numOfSubs);
+    assert(pQueryInfo->numOfTables == 1 && pNew->cmd.numOfClause == 1 && trsupport->subqueryIndex < pSql->subState.numOfSub);
    
    // launch subquery for each vnode, so the subquery index equals to the vgroupIndex.
    STableMetaInfo *pTableMetaInfo = tscGetMetaInfo(pQueryInfo, table_index);
@ -1893,7 +1881,6 @@ void tscRetrieveDataRes(void *param, TAOS_RES *tres, int code) {
 static void multiVnodeInsertFinalize(void* param, TAOS_RES* tres, int numOfRows) {
  SInsertSupporter *pSupporter = (SInsertSupporter *)param;
  SSqlObj* pParentObj = pSupporter->pSql;
-  SSubqueryState* pState = pSupporter->pState;

  // record the total inserted rows
  if (numOfRows > 0) {
@ -1908,15 +1895,13 @@ static void multiVnodeInsertFinalize(void* param, TAOS_RES* tres, int numOfRows)
  }

  taosTFree(pSupporter);
-  if (atomic_sub_fetch_32(&pState->numOfRemain, 1) > 0) {
+
+  if (atomic_sub_fetch_32(&pParentObj->subState.numOfRemain, 1) > 0) {
    return;
  }
  
  tscDebug("%p Async insertion completed, total inserted:%" PRId64, pParentObj, pParentObj->res.numOfRows);

-  // release data block data
-  taosTFree(pState);
-
  // restore user defined fp
  pParentObj->fp = pParentObj->fetchFp;

@ -1937,7 +1922,7 @@ int32_t tscHandleInsertRetry(SSqlObj* pSql) {
  SSqlRes* pRes = &pSql->res;

  SInsertSupporter* pSupporter = (SInsertSupporter*) pSql->param;
-  assert(pSupporter->index < pSupporter->pState->numOfTotal);
+  assert(pSupporter->index < pSupporter->pSql->subState.numOfSub);

  STableDataBlocks* pTableDataBlock = taosArrayGetP(pCmd->pDataBlocks, pSupporter->index);
  int32_t code = tscCopyDataBlockToPayload(pSql, pTableDataBlock);
@ -1954,33 +1939,29 @@ int32_t tscHandleMultivnodeInsert(SSqlObj *pSql) {
  SSqlCmd *pCmd = &pSql->cmd;
  SSqlRes *pRes = &pSql->res;

-  pSql->numOfSubs = (uint16_t)taosArrayGetSize(pCmd->pDataBlocks);
-  assert(pSql->numOfSubs > 0);
+  pSql->subState.numOfSub = (uint16_t)taosArrayGetSize(pCmd->pDataBlocks);
+  assert(pSql->subState.numOfSub > 0);

  pRes->code = TSDB_CODE_SUCCESS;

  // the number of already initialized subqueries
  int32_t numOfSub = 0;

-  SSubqueryState *pState = calloc(1, sizeof(SSubqueryState));
-  pState->numOfTotal = pSql->numOfSubs;
-  pState->numOfRemain = pSql->numOfSubs;
-
-  pSql->pSubs = calloc(pSql->numOfSubs, POINTER_BYTES);
+  pSql->subState.numOfRemain = pSql->subState.numOfSub;
+  pSql->pSubs = calloc(pSql->subState.numOfSub, POINTER_BYTES);
  if (pSql->pSubs == NULL) {
    goto _error;
  }

-  tscDebug("%p submit data to %d vnode(s)", pSql, pSql->numOfSubs);
+  tscDebug("%p submit data to %d vnode(s)", pSql, pSql->subState.numOfSub);

-  while(numOfSub < pSql->numOfSubs) {
+  while(numOfSub < pSql->subState.numOfSub) {
    SInsertSupporter* pSupporter = calloc(1, sizeof(SInsertSupporter));
    if (pSupporter == NULL) {
      goto _error;
    }

    pSupporter->pSql   = pSql;
-    pSupporter->pState = pState;
    pSupporter->index  = numOfSub;

    SSqlObj *pNew = createSimpleSubObj(pSql, multiVnodeInsertFinalize, pSupporter, TSDB_SQL_INSERT);
@ -2003,12 +1984,12 @@ int32_t tscHandleMultivnodeInsert(SSqlObj *pSql) {
      numOfSub++;
    } else {
      tscDebug("%p prepare submit data block failed in async insertion, vnodeIdx:%d, total:%d, code:%s", pSql, numOfSub,
-               pSql->numOfSubs, tstrerror(pRes->code));
+               pSql->subState.numOfSub, tstrerror(pRes->code));
      goto _error;
    }
  }
  
-  if (numOfSub < pSql->numOfSubs) {
+  if (numOfSub < pSql->subState.numOfSub) {
    tscError("%p failed to prepare subObj structure and launch sub-insertion", pSql);
    pRes->code = TSDB_CODE_TSC_OUT_OF_MEMORY;
    goto _error;
@ -2026,14 +2007,13 @@ int32_t tscHandleMultivnodeInsert(SSqlObj *pSql) {
  return TSDB_CODE_SUCCESS;

  _error:
-  taosTFree(pState);
  return TSDB_CODE_TSC_OUT_OF_MEMORY;
 }

 static char* getResultBlockPosition(SSqlCmd* pCmd, SSqlRes* pRes, int32_t columnIndex, int16_t* bytes) {
  SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(pCmd, pCmd->clauseIndex);

-  SFieldSupInfo* pInfo = (SFieldSupInfo*) TARRAY_GET_ELEM(pQueryInfo->fieldsInfo.pSupportInfo, columnIndex);
+  SInternalField* pInfo = (SInternalField*) TARRAY_GET_ELEM(pQueryInfo->fieldsInfo.internalField, columnIndex);
  assert(pInfo->pSqlExpr != NULL);

  *bytes = pInfo->pSqlExpr->resBytes;
@ -2048,7 +2028,7 @@ static void doBuildResFromSubqueries(SSqlObj* pSql) {
  SQueryInfo *pQueryInfo = tscGetQueryInfoDetail(&pSql->cmd, pSql->cmd.clauseIndex);

  int32_t numOfRes = INT32_MAX;
-  for (int32_t i = 0; i < pSql->numOfSubs; ++i) {
+  for (int32_t i = 0; i < pSql->subState.numOfSub; ++i) {
    if (pSql->pSubs[i] == NULL) {
      continue;
    }
@ -2141,7 +2121,7 @@ static void transferNcharData(SSqlObj *pSql, int32_t columnIndex, TAOS_FIELD *pF
    
    int32_t length = taosUcs4ToMbs(pRes->tsrow[columnIndex], pRes->length[columnIndex], pRes->buffer[columnIndex]);
    if ( length >= 0 ) {
-      pRes->tsrow[columnIndex] = pRes->buffer[columnIndex];
+      pRes->tsrow[columnIndex] = (unsigned char*)pRes->buffer[columnIndex];
      pRes->length[columnIndex] = length;
    } else {
      tscError("%p charset:%s to %s. val:%s convert failed.", pSql, DEFAULT_UNICODE_ENCODEC, tsCharset, (char*)pRes->tsrow[columnIndex]);
@ -2169,7 +2149,7 @@ static char *getArithemicInputSrc(void *param, const char *name, int32_t colId)
  return pSupport->data[index] + pSupport->offset * pExpr->resBytes;
 }

-void **doSetResultRowData(SSqlObj *pSql, bool finalResult) {
+TAOS_ROW doSetResultRowData(SSqlObj *pSql, bool finalResult) {
  SSqlCmd *pCmd = &pSql->cmd;
  SSqlRes *pRes = &pSql->res;

@ -2183,7 +2163,7 @@ void **doSetResultRowData(SSqlObj *pSql, bool finalResult) {

  size_t size = tscNumOfFields(pQueryInfo);
  for (int i = 0; i < size; ++i) {
-    SFieldSupInfo* pSup = TARRAY_GET_ELEM(pQueryInfo->fieldsInfo.pSupportInfo, i);
+    SInternalField* pSup = TARRAY_GET_ELEM(pQueryInfo->fieldsInfo.internalField, i);
    if (pSup->pSqlExpr != NULL) {
      tscGetResultColumnChr(pRes, &pQueryInfo->fieldsInfo, i);
    }
@ -2193,7 +2173,7 @@ void **doSetResultRowData(SSqlObj *pSql, bool finalResult) {
      continue;
    }

-    TAOS_FIELD *pField = TARRAY_GET_ELEM(pQueryInfo->fieldsInfo.pFields, i);
+    TAOS_FIELD *pField = TARRAY_GET_ELEM(pQueryInfo->fieldsInfo.internalField, i);
    if (pRes->tsrow[i] != NULL && pField->type == TSDB_DATA_TYPE_NCHAR) {
      transferNcharData(pSql, i, pField);
    }
@ -2222,7 +2202,7 @@ void **doSetResultRowData(SSqlObj *pSql, bool finalResult) {

      tExprTreeCalcTraverse(pRes->pArithSup->pArithExpr->pExpr, 1, pRes->buffer[i], pRes->pArithSup,
          TSDB_ORDER_ASC, getArithemicInputSrc);
-      pRes->tsrow[i] = pRes->buffer[i];
+      pRes->tsrow[i] = (unsigned char*)pRes->buffer[i];
    }
  }

@ -2238,7 +2218,7 @@ static UNUSED_FUNC bool tscHasRemainDataInSubqueryResultSet(SSqlObj *pSql) {
  if (tscNonOrderedProjectionQueryOnSTable(pQueryInfo, 0)) {
    bool allSubqueryExhausted = true;
    
-    for (int32_t i = 0; i < pSql->numOfSubs; ++i) {
+    for (int32_t i = 0; i < pSql->subState.numOfSub; ++i) {
      if (pSql->pSubs[i] == NULL) {
        continue;
      }
@ -2264,7 +2244,7 @@ static UNUSED_FUNC bool tscHasRemainDataInSubqueryResultSet(SSqlObj *pSql) {
    
    hasData = !allSubqueryExhausted;
  } else {  // otherwise, in case inner join, if any subquery exhausted, query completed.
-    for (int32_t i = 0; i < pSql->numOfSubs; ++i) {
+    for (int32_t i = 0; i < pSql->subState.numOfSub; ++i) {
      if (pSql->pSubs[i] == 0) {
        continue;
      }
--- a/src/client/src/tscSystem.c
+++ b/src/client/src/tscSystem.c
@ -77,6 +77,7 @@ int32_t tscInitRpc(const char *user, const char *secretEncrypt, void **pDnodeCon
  return 0;
 }

+
 void taos_init_imp(void) {
  char temp[128];
  
@ -124,8 +125,9 @@ void taos_init_imp(void) {

  double factor = (tscEmbedded == 0)? 2.0:4.0;
  tscNumOfThreads = (int)(tsNumOfCores * tsNumOfThreadsPerCore / factor);
-
-  if (tscNumOfThreads < 2) tscNumOfThreads = 2;
+  if (tscNumOfThreads < 2) {
+    tscNumOfThreads = 2;
+  }

  tscQhandle = taosInitScheduler(queueSize, tscNumOfThreads, "tsc");
  if (NULL == tscQhandle) {
@ -140,8 +142,8 @@ void taos_init_imp(void) {

  int64_t refreshTime = 10; // 10 seconds by default
  if (tscMetaCache == NULL) {
-    tscMetaCache = taosCacheInit(TSDB_DATA_TYPE_BINARY, refreshTime, false, NULL, "tableMeta");
-    tscObjCache = taosCacheInit(TSDB_CACHE_PTR_KEY, refreshTime / 2, false, tscFreeSqlObjInCache, "sqlObj");
+    tscMetaCache = taosCacheInit(TSDB_DATA_TYPE_BINARY, refreshTime, false, tscFreeTableMetaHelper, "tableMeta");
+    tscObjCache = taosCacheInit(TSDB_CACHE_PTR_KEY, refreshTime / 2, false, tscFreeRegisteredSqlObj, "sqlObj");
  }

  tscDebug("client is initialized successfully");
--- a/src/client/src/tscUtil.c
+++ b/src/client/src/tscUtil.c
@ -114,9 +114,9 @@ bool tscIsTwoStageSTableQuery(SQueryInfo* pQueryInfo, int32_t tableIndex) {
  }
  
  // for select query super table, the super table vgroup list can not be null in any cases.
-  if (pQueryInfo->command == TSDB_SQL_SELECT && UTIL_TABLE_IS_SUPER_TABLE(pTableMetaInfo)) {
-    assert(pTableMetaInfo->vgroupList != NULL);
-  }
+  // if (pQueryInfo->command == TSDB_SQL_SELECT && UTIL_TABLE_IS_SUPER_TABLE(pTableMetaInfo)) {
+  //   assert(pTableMetaInfo->vgroupList != NULL);
+  // }
  
  if ((pQueryInfo->type & TSDB_QUERY_TYPE_FREE_RESOURCE) == TSDB_QUERY_TYPE_FREE_RESOURCE) {
    return false;
@ -360,26 +360,26 @@ void tscPartiallyFreeSqlObj(SSqlObj* pSql) {
  tscFreeSqlResult(pSql);
  
  taosTFree(pSql->pSubs);
-  pSql->numOfSubs = 0;
+  pSql->subState.numOfSub = 0;
  pSql->self = 0;
  
  tscResetSqlCmdObj(pCmd, false);
 }

-static UNUSED_FUNC void tscFreeSubobj(SSqlObj* pSql) {
-  if (pSql->numOfSubs == 0) {
+static void tscFreeSubobj(SSqlObj* pSql) {
+  if (pSql->subState.numOfSub == 0) {
    return;
  }

-  tscDebug("%p start to free sub SqlObj, numOfSub:%d", pSql, pSql->numOfSubs);
+  tscDebug("%p start to free sub SqlObj, numOfSub:%d", pSql, pSql->subState.numOfSub);

-  for(int32_t i = 0; i < pSql->numOfSubs; ++i) {
+  for(int32_t i = 0; i < pSql->subState.numOfSub; ++i) {
    tscDebug("%p free sub SqlObj:%p, index:%d", pSql, pSql->pSubs[i], i);
    taos_free_result(pSql->pSubs[i]);
    pSql->pSubs[i] = NULL;
  }

-  pSql->numOfSubs = 0;
+  pSql->subState.numOfSub = 0;
 }

 /**
@ -389,7 +389,7 @@ static UNUSED_FUNC void tscFreeSubobj(SSqlObj* pSql) {
 *
 * @param pSql
 */
-void tscFreeSqlObjInCache(void *pSql) {
+void tscFreeRegisteredSqlObj(void *pSql) {
  assert(pSql != NULL);

  SSqlObj** p = (SSqlObj**)pSql;
@ -408,6 +408,24 @@ void tscFreeSqlObjInCache(void *pSql) {
  }
 }

+void tscFreeTableMetaHelper(void *pTableMeta) {
+  STableMeta* p = (STableMeta*) pTableMeta;
+
+  int32_t numOfEps = p->vgroupInfo.numOfEps;
+  assert(numOfEps >= 0 && numOfEps <= TSDB_MAX_REPLICA);
+
+  for(int32_t i = 0; i < numOfEps; ++i) {
+    taosTFree(p->vgroupInfo.epAddr[i].fqdn);
+  }
+
+  int32_t numOfEps1 = p->corVgroupInfo.numOfEps;
+  assert(numOfEps1 >= 0 && numOfEps1 <= TSDB_MAX_REPLICA);
+
+  for(int32_t i = 0; i < numOfEps1; ++i) {
+    taosTFree(p->corVgroupInfo.epAddr[i].fqdn);
+  }
+}
+
 void tscFreeSqlObj(SSqlObj* pSql) {
  if (pSql == NULL || pSql->signature != pSql) {
    return;
@ -415,7 +433,9 @@ void tscFreeSqlObj(SSqlObj* pSql) {

  tscDebug("%p start to free sqlObj", pSql);

+  pSql->res.code = TSDB_CODE_TSC_QUERY_CANCELLED;
  tscFreeSubobj(pSql);
+
  tscPartiallyFreeSqlObj(pSql);

  pSql->signature = NULL;
@ -684,16 +704,14 @@ static int32_t getRowExpandSize(STableMeta* pTableMeta) {
 int32_t tscMergeTableDataBlocks(SSqlObj* pSql, SArray* pTableDataBlockList) {
  SSqlCmd* pCmd = &pSql->cmd;

-  // the maximum expanded size in byte when a row-wise data is converted to SDataRow format
-  STableDataBlocks* pOneTableBlock = taosArrayGetP(pTableDataBlockList, 0);
-  int32_t expandSize = getRowExpandSize(pOneTableBlock->pTableMeta);
-
  void* pVnodeDataBlockHashList = taosHashInit(128, taosGetDefaultHashFunction(TSDB_DATA_TYPE_BIGINT), true, false);
  SArray* pVnodeDataBlockList = taosArrayInit(8, POINTER_BYTES);

  size_t total = taosArrayGetSize(pTableDataBlockList);
  for (int32_t i = 0; i < total; ++i) {
-    pOneTableBlock = taosArrayGetP(pTableDataBlockList, i);
+    // the maximum expanded size in byte when a row-wise data is converted to SDataRow format
+    STableDataBlocks* pOneTableBlock = taosArrayGetP(pTableDataBlockList, i);
+    int32_t expandSize = getRowExpandSize(pOneTableBlock->pTableMeta);
    STableDataBlocks* dataBuf = NULL;
    
    int32_t ret =
@ -827,35 +845,30 @@ TAOS_FIELD tscCreateField(int8_t type, const char* name, int16_t bytes) {
  return f;
 }

-SFieldSupInfo* tscFieldInfoAppend(SFieldInfo* pFieldInfo, TAOS_FIELD* pField) {
+SInternalField* tscFieldInfoAppend(SFieldInfo* pFieldInfo, TAOS_FIELD* pField) {
  assert(pFieldInfo != NULL);
-  taosArrayPush(pFieldInfo->pFields, pField);
  pFieldInfo->numOfOutput++;
  
-  struct SFieldSupInfo info = {
+  struct SInternalField info = {
    .pSqlExpr = NULL,
    .pArithExprInfo = NULL,
    .visible = true,
  };

-  return taosArrayPush(pFieldInfo->pSupportInfo, &info);
+  info.field = *pField;
+  return taosArrayPush(pFieldInfo->internalField, &info);
 }

-SFieldSupInfo* tscFieldInfoGetSupp(SFieldInfo* pFieldInfo, int32_t index) {
-  return TARRAY_GET_ELEM(pFieldInfo->pSupportInfo, index);
-}
-
-SFieldSupInfo* tscFieldInfoInsert(SFieldInfo* pFieldInfo, int32_t index, TAOS_FIELD* field) {
-  taosArrayInsert(pFieldInfo->pFields, index, field);
+SInternalField* tscFieldInfoInsert(SFieldInfo* pFieldInfo, int32_t index, TAOS_FIELD* field) {
  pFieldInfo->numOfOutput++;
-  
-  struct SFieldSupInfo info = {
+  struct SInternalField info = {
      .pSqlExpr = NULL,
      .pArithExprInfo = NULL,
      .visible = true,
  };

-  return taosArrayInsert(pFieldInfo->pSupportInfo, index, &info);
+  info.field = *field;
+  return taosArrayInsert(pFieldInfo->internalField, index, &info);
 }

 void tscFieldInfoUpdateOffset(SQueryInfo* pQueryInfo) {
@ -889,29 +902,18 @@ void tscFieldInfoUpdateOffsetForInterResult(SQueryInfo* pQueryInfo) {
  }
 }

-void tscFieldInfoCopy(SFieldInfo* dst, const SFieldInfo* src) {
-  dst->numOfOutput = src->numOfOutput;
-
-  if (dst->pFields == NULL) {
-    dst->pFields = taosArrayClone(src->pFields);
-  } else {
-    taosArrayCopy(dst->pFields, src->pFields);
-  }
-  
-  if (dst->pSupportInfo == NULL) {
-    dst->pSupportInfo = taosArrayClone(src->pSupportInfo);
-  } else {
-    taosArrayCopy(dst->pSupportInfo, src->pSupportInfo);
-  }
+SInternalField* tscFieldInfoGetInternalField(SFieldInfo* pFieldInfo, int32_t index) {
+  assert(index < pFieldInfo->numOfOutput);
+  return TARRAY_GET_ELEM(pFieldInfo->internalField, index);
 }

 TAOS_FIELD* tscFieldInfoGetField(SFieldInfo* pFieldInfo, int32_t index) {
  assert(index < pFieldInfo->numOfOutput);
-  return TARRAY_GET_ELEM(pFieldInfo->pFields, index);
+  return &((SInternalField*)TARRAY_GET_ELEM(pFieldInfo->internalField, index))->field;
 }

 int16_t tscFieldInfoGetOffset(SQueryInfo* pQueryInfo, int32_t index) {
-  SFieldSupInfo* pInfo = tscFieldInfoGetSupp(&pQueryInfo->fieldsInfo, index);
+  SInternalField* pInfo = tscFieldInfoGetInternalField(&pQueryInfo->fieldsInfo, index);
  assert(pInfo != NULL && pInfo->pSqlExpr != NULL);

  return pInfo->pSqlExpr->offset;
@ -958,10 +960,8 @@ void tscFieldInfoClear(SFieldInfo* pFieldInfo) {
    return;
  }

-  taosArrayDestroy(pFieldInfo->pFields);
-  
  for(int32_t i = 0; i < pFieldInfo->numOfOutput; ++i) {
-    SFieldSupInfo* pInfo = taosArrayGet(pFieldInfo->pSupportInfo, i);
+    SInternalField* pInfo = taosArrayGet(pFieldInfo->internalField, i);
    
    if (pInfo->pArithExprInfo != NULL) {
      tExprTreeDestroy(&pInfo->pArithExprInfo->pExpr, NULL);
@ -969,7 +969,9 @@ void tscFieldInfoClear(SFieldInfo* pFieldInfo) {
    }
  }
  
-  taosArrayDestroy(pFieldInfo->pSupportInfo);
+  taosArrayDestroy(pFieldInfo->internalField);
+  taosTFree(pFieldInfo->final);
+
  memset(pFieldInfo, 0, sizeof(SFieldInfo));
 }

@ -1516,13 +1518,6 @@ void tscSetFreeHeatBeat(STscObj* pObj) {
  pQueryInfo->type = TSDB_QUERY_TYPE_FREE_RESOURCE;
 }

-bool tscShouldFreeHeartBeat(SSqlObj* pHb) {
-  assert(pHb == pHb->signature);
-
-  SQueryInfo* pQueryInfo = tscGetQueryInfoDetail(&pHb->cmd, 0);
-  return pQueryInfo->type == TSDB_QUERY_TYPE_FREE_RESOURCE;
-}
-
 /*
 * the following four kinds of SqlObj should not be freed
 * 1. SqlObj for stream computing
@ -1620,11 +1615,8 @@ STableMetaInfo* tscGetTableMetaInfoByUid(SQueryInfo* pQueryInfo, uint64_t uid, i
 }

 void tscInitQueryInfo(SQueryInfo* pQueryInfo) {
-  assert(pQueryInfo->fieldsInfo.pFields == NULL);
-  pQueryInfo->fieldsInfo.pFields = taosArrayInit(4, sizeof(TAOS_FIELD));
-  
-  assert(pQueryInfo->fieldsInfo.pSupportInfo == NULL);
-  pQueryInfo->fieldsInfo.pSupportInfo = taosArrayInit(4, sizeof(SFieldSupInfo));
+  assert(pQueryInfo->fieldsInfo.internalField == NULL);
+  pQueryInfo->fieldsInfo.internalField = taosArrayInit(4, sizeof(SInternalField));
  
  assert(pQueryInfo->exprList == NULL);
  pQueryInfo->exprList   = taosArrayInit(4, POINTER_BYTES);
@ -1687,8 +1679,14 @@ void tscClearSubqueryInfo(SSqlCmd* pCmd) {

 void tscFreeVgroupTableInfo(SArray* pVgroupTables) {
  if (pVgroupTables != NULL) {
-    for (size_t i = 0; i < taosArrayGetSize(pVgroupTables); i++) {
+    size_t num = taosArrayGetSize(pVgroupTables);
+    for (size_t i = 0; i < num; i++) {
      SVgroupTableInfo* pInfo = taosArrayGet(pVgroupTables, i);
+
+      for(int32_t j = 0; j < pInfo->vgInfo.numOfEps; ++j) {
+        taosTFree(pInfo->vgInfo.epAddr[j].fqdn);
+      }
+
      taosArrayDestroy(pInfo->itemList);
    }
    taosArrayDestroy(pVgroupTables);
@ -1700,6 +1698,7 @@ void clearAllTableMetaInfo(SQueryInfo* pQueryInfo, const char* address, bool rem
  
  for(int32_t i = 0; i < pQueryInfo->numOfTables; ++i) {
    STableMetaInfo* pTableMetaInfo = tscGetMetaInfo(pQueryInfo, i);
+
    tscFreeVgroupTableInfo(pTableMetaInfo->pVgroupTables);
    tscClearTableMetaInfo(pTableMetaInfo, removeFromCache);
    free(pTableMetaInfo);
@ -1732,13 +1731,7 @@ STableMetaInfo* tscAddTableMetaInfo(SQueryInfo* pQueryInfo, const char* name, ST
  pTableMetaInfo->pTableMeta = pTableMeta;
  
  if (vgroupList != NULL) {
-    size_t size = sizeof(SVgroupsInfo) + sizeof(SCMVgroupInfo) * vgroupList->numOfVgroups;
-    pTableMetaInfo->vgroupList = malloc(size);
-    if (pTableMetaInfo->vgroupList == NULL) {
-      return NULL;
-    }
-
-    memcpy(pTableMetaInfo->vgroupList, vgroupList, size);
+    pTableMetaInfo->vgroupList = tscVgroupInfoClone(vgroupList);
  }

  pTableMetaInfo->tagColList = taosArrayInit(4, POINTER_BYTES);
@ -1767,8 +1760,7 @@ void tscClearTableMetaInfo(STableMetaInfo* pTableMetaInfo, bool removeFromCache)
    taosCacheRelease(tscMetaCache, (void**)&(pTableMetaInfo->pTableMeta), removeFromCache);
  }

-  taosTFree(pTableMetaInfo->vgroupList);
-  
+  pTableMetaInfo->vgroupList = tscVgroupInfoClear(pTableMetaInfo->vgroupList);
  tscColumnListDestroy(pTableMetaInfo->tagColList);
  pTableMetaInfo->tagColList = NULL;
 }
@ -1836,54 +1828,23 @@ 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 = (uint8_t)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 = (int32_t)tscSqlExprNumOfExprs(pNewQueryInfo);
  if (numOfOutput == 0) {
    return;
  }

-  size_t      numOfExprs = tscSqlExprNumOfExprs(pQueryInfo);
-  SFieldInfo* pFieldInfo = &pQueryInfo->fieldsInfo;
-
-  // set the field info in pNewQueryInfo object
+  // set the field info in pNewQueryInfo object according to sqlExpr information
+  size_t numOfExprs = tscSqlExprNumOfExprs(pNewQueryInfo);
  for (int32_t i = 0; i < numOfExprs; ++i) {
-    SSqlExpr* pExpr = tscSqlExprGet(pQueryInfo, i);
+    SSqlExpr* pExpr = tscSqlExprGet(pNewQueryInfo, 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);
-      }
-    }
+    TAOS_FIELD f = tscCreateField((int8_t) pExpr->resType, pExpr->aliasName, pExpr->resBytes);
+    SInternalField* pInfo1 = tscFieldInfoAppend(&pNewQueryInfo->fieldsInfo, &f);
+    pInfo1->pSqlExpr = pExpr;
  }

-  // make sure the the sqlExpr for each fields is correct
-  numOfExprs = tscSqlExprNumOfExprs(pNewQueryInfo);
-
-  // update the pSqlExpr pointer in SFieldSupInfo according the field name
+  // update the pSqlExpr pointer in SInternalField 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);
@ -1893,7 +1854,7 @@ static void doSetSqlExprAndResultFieldInfo(SQueryInfo* pQueryInfo, SQueryInfo* p
      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);
+        SInternalField* pInfo = tscFieldInfoGetInternalField(&pNewQueryInfo->fieldsInfo, f);
        pInfo->pSqlExpr = pExpr1;

        matched = true;
@ -2291,7 +2252,7 @@ void tscTryQueryNextVnode(SSqlObj* pSql, __async_cb_func_t fp) {
     *
     * For super table join with projection query, if anyone of the subquery is exhausted, the query completed.
     */
-    pSql->numOfSubs = 0;
+    pSql->subState.numOfSub = 0;
    pCmd->command = TSDB_SQL_SELECT;

    tscResetForNextRetrieve(pRes);
@ -2323,7 +2284,7 @@ void tscTryQueryNextClause(SSqlObj* pSql, __async_cb_func_t fp) {
  pRes->numOfTotal = num;
  
  taosTFree(pSql->pSubs);
-  pSql->numOfSubs = 0;
+  pSql->subState.numOfSub = 0;
  pSql->fp = fp;

  tscDebug("%p try data in the next subclause:%d, total subclause:%d", pSql, pCmd->clauseIndex, pCmd->numOfClause);
@ -2408,3 +2369,58 @@ void tscClearSqlOwner(SSqlObj* pSql) {
  assert(taosCheckPthreadValid(pSql->owner));
  atomic_store_64(&pSql->owner, 0);
 }
+
+SVgroupsInfo* tscVgroupInfoClone(SVgroupsInfo *vgroupList) {
+  if (vgroupList == NULL) {
+    return NULL;
+  }
+
+  size_t size = sizeof(SVgroupsInfo) + sizeof(SCMVgroupInfo) * vgroupList->numOfVgroups;
+  SVgroupsInfo* pNew = calloc(1, size);
+  if (pNew == NULL) {
+    return NULL;
+  }
+
+  pNew->numOfVgroups = vgroupList->numOfVgroups;
+
+  for(int32_t i = 0; i < vgroupList->numOfVgroups; ++i) {
+    SCMVgroupInfo* pNewVInfo = &pNew->vgroups[i];
+
+    SCMVgroupInfo* pvInfo = &vgroupList->vgroups[i];
+    pNewVInfo->vgId = pvInfo->vgId;
+    pNewVInfo->numOfEps = pvInfo->numOfEps;
+
+    for(int32_t j = 0; j < pvInfo->numOfEps; ++j) {
+      pNewVInfo->epAddr[j].fqdn = strdup(pvInfo->epAddr[j].fqdn);
+      pNewVInfo->epAddr[j].port = pvInfo->epAddr[j].port;
+    }
+  }
+
+  return pNew;
+}
+
+void* tscVgroupInfoClear(SVgroupsInfo *vgroupList) {
+  if (vgroupList == NULL) {
+    return NULL;
+  }
+
+  for(int32_t i = 0; i < vgroupList->numOfVgroups; ++i) {
+    SCMVgroupInfo* pVgroupInfo = &vgroupList->vgroups[i];
+
+    for(int32_t j = 0; j < pVgroupInfo->numOfEps; ++j) {
+      taosTFree(pVgroupInfo->epAddr[j].fqdn);
+    }
+  }
+
+  taosTFree(vgroupList);
+  return NULL;
+}
+
+void tscSCMVgroupInfoCopy(SCMVgroupInfo* dst, const SCMVgroupInfo* src) {
+  dst->vgId = src->vgId;
+  dst->numOfEps = src->numOfEps;
+  for(int32_t i = 0; i < dst->numOfEps; ++i) {
+    dst->epAddr[i].port = src->epAddr[i].port;
+    dst->epAddr[i].fqdn = strdup(src->epAddr[i].fqdn);
+  }
+}
--- a/src/common/inc/tglobal.h
+++ b/src/common/inc/tglobal.h
@ -34,6 +34,7 @@ extern int32_t  tsStatusInterval;
 extern int32_t  tsNumOfMnodes;
 extern int32_t  tsEnableVnodeBak;
 extern int32_t  tsEnableTelemetryReporting;
+extern char     tsEmail[];

 // common
 extern int      tsRpcTimer;
--- a/src/common/src/tdataformat.c
+++ b/src/common/src/tdataformat.c
@ -566,7 +566,7 @@ int tdSetKVRowDataOfCol(SKVRow *orow, int16_t colId, int8_t type, void *value) {
  SKVRow   nrow = NULL;
  void *   ptr = taosbsearch(&colId, kvRowColIdx(row), kvRowNCols(row), sizeof(SColIdx), comparTagId, TD_GE);

-  if (ptr == NULL || ((SColIdx *)ptr)->colId < colId) { // need to add a column value to the row
+  if (ptr == NULL || ((SColIdx *)ptr)->colId > colId) { // need to add a column value to the row
    int diff = IS_VAR_DATA_TYPE(type) ? varDataTLen(value) : TYPE_BYTES[type];
    nrow = malloc(kvRowLen(row) + sizeof(SColIdx) + diff);
    if (nrow == NULL) return -1;
--- a/src/common/src/tglobal.c
+++ b/src/common/src/tglobal.c
@ -42,6 +42,7 @@ int32_t  tsStatusInterval = 1;  // second
 int32_t  tsNumOfMnodes = 3;
 int32_t  tsEnableVnodeBak = 1;
 int32_t  tsEnableTelemetryReporting = 1;
+char     tsEmail[TSDB_FQDN_LEN] = {0};

 // common
 int32_t tsRpcTimer = 1000;
@ -307,6 +308,8 @@ bool taosCfgDynamicOptions(char *msg) {

 static void doInitGlobalConfig(void) {
  osInit();
+  srand(taosSafeRand());
+
  SGlobalCfg cfg = {0};
  
  // ip address
--- a/src/connector/jdbc/CMakeLists.txt
+++ b/src/connector/jdbc/CMakeLists.txt
@ -8,7 +8,7 @@ IF (TD_MVN_INSTALLED)
  ADD_CUSTOM_COMMAND(OUTPUT ${JDBC_CMD_NAME}
    POST_BUILD
    COMMAND mvn -Dmaven.test.skip=true install -f ${CMAKE_CURRENT_SOURCE_DIR}/pom.xml
-    COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_SOURCE_DIR}/target/taos-jdbcdriver-2.0.0-dist.jar ${LIBRARY_OUTPUT_PATH}
+    COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_SOURCE_DIR}/target/taos-jdbcdriver-2.0.8-dist.jar ${LIBRARY_OUTPUT_PATH}
    COMMAND mvn -Dmaven.test.skip=true clean -f ${CMAKE_CURRENT_SOURCE_DIR}/pom.xml
    COMMENT "build jdbc driver")
  ADD_CUSTOM_TARGET(${JDBC_TARGET_NAME} ALL WORKING_DIRECTORY ${EXECUTABLE_OUTPUT_PATH} DEPENDS ${JDBC_CMD_NAME})
--- a/src/connector/jdbc/pom.xml
+++ b/src/connector/jdbc/pom.xml
@ -3,7 +3,7 @@
    <modelVersion>4.0.0</modelVersion>
    <groupId>com.taosdata.jdbc</groupId>
    <artifactId>taos-jdbcdriver</artifactId>
-    <version>2.0.0</version>
+    <version>2.0.8</version>
    <packaging>jar</packaging>
    <name>JDBCDriver</name>
    <url>https://github.com/taosdata/TDengine/tree/master/src/connector/jdbc</url>
--- a/src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBDatabaseMetaData.java
+++ b/src/connector/jdbc/src/main/java/com/taosdata/jdbc/TSDBDatabaseMetaData.java
@ -587,7 +587,6 @@ public class TSDBDatabaseMetaData implements java.sql.DatabaseMetaData {
    public ResultSet getColumns(String catalog, String schemaPattern, String tableNamePattern, String columnNamePattern)
            throws SQLException {

-
        /** add by zyyang **********/
        Statement stmt = null;
        if (null != conn && !conn.isClosed()) {
--- a/src/connector/odbc/CMakeLists.txt
+++ b/src/connector/odbc/CMakeLists.txt
@ -0,0 +1,33 @@
+CMAKE_MINIMUM_REQUIRED(VERSION 2.8)
+PROJECT(TDengine)
+
+IF (TD_LINUX_64)
+  find_program(HAVE_ODBCINST NAMES odbcinst)
+
+  IF (HAVE_ODBCINST)
+    include(CheckSymbolExists)
+    # shall we revert CMAKE_REQUIRED_LIBRARIES and how?
+    set(CMAKE_REQUIRED_LIBRARIES odbc)
+    check_symbol_exists(SQLExecute "sql.h" HAVE_ODBC_DEV)
+    if(NOT (HAVE_ODBC_DEV))
+      unset(HAVE_ODBC_DEV CACHE)
+      message(WARNING "unixodbc-dev is not installed yet, you may install it under ubuntu by typing: sudo apt install unixodbc-dev")
+    else ()
+      message(STATUS "unixodbc/unixodbc-dev are installed, and odbc connector will be built")
+      AUX_SOURCE_DIRECTORY(src SRC)
+
+      # generate dynamic library (*.so)
+      ADD_LIBRARY(todbc SHARED ${SRC})
+      SET_TARGET_PROPERTIES(todbc PROPERTIES CLEAN_DIRECT_OUTPUT 1)
+      SET_TARGET_PROPERTIES(todbc PROPERTIES VERSION ${TD_VER_NUMBER} SOVERSION 1)
+      TARGET_LINK_LIBRARIES(todbc taos)
+
+      install(CODE "execute_process(COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/src/install.sh ${CMAKE_BINARY_DIR})")
+
+      ADD_SUBDIRECTORY(tests)
+    endif()
+  ELSE ()
+    message(WARNING "unixodbc is not installed yet, you may install it under ubuntu by typing: sudo apt install unixodbc")
+  ENDIF ()
+ENDIF ()
+
--- a/src/connector/odbc/src/install.sh
+++ b/src/connector/odbc/src/install.sh
@ -0,0 +1,25 @@
+#!/bin/bash
+
+set -u
+
+BLD_DIR="$1"
+
+rm -f "${BLD_DIR}/template.ini"
+rm -f "${BLD_DIR}/template.dsn"
+
+cat > "${BLD_DIR}/template.ini" <<EOF
+[TAOS]
+Description = taos odbc driver
+Driver = ${BLD_DIR}/build/lib/libtodbc.so
+EOF
+
+cat > "${BLD_DIR}/template.dsn" <<EOF
+[TAOS_DSN]
+Description=Connection to TAOS
+Driver=TAOS
+EOF
+
+sudo odbcinst -i -d -f "${BLD_DIR}/template.ini" &&
+odbcinst -i -s -f "${BLD_DIR}/template.dsn" &&
+echo "odbc install done"
+
--- a/src/connector/odbc/src/todbc.c
+++ b/src/connector/odbc/src/todbc.c
--- a/src/connector/odbc/src/todbc_util.c
+++ b/src/connector/odbc/src/todbc_util.c
@ -0,0 +1,238 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * 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 "todbc_util.h"
+
+#include "iconv.h"
+
+#include <sql.h>
+#include <sqltypes.h>
+#include <sqlext.h>
+#include <stdlib.h>
+#include <string.h>
+
+const char* sql_sql_type(int type) {
+  switch (type) {
+    case SQL_BIT:                               return "SQL_BIT";
+    case SQL_TINYINT:                           return "SQL_TINYINT";
+    case SQL_SMALLINT:                          return "SQL_SMALLINT";
+    case SQL_INTEGER:                           return "SQL_INTEGER";
+    case SQL_BIGINT:                            return "SQL_BIGINT";
+    case SQL_FLOAT:                             return "SQL_FLOAT";
+    case SQL_DOUBLE:                            return "SQL_DOUBLE";
+    case SQL_DECIMAL:                           return "SQL_DECIMAL";
+    case SQL_NUMERIC:                           return "SQL_NUMERIC";
+    case SQL_REAL:                              return "SQL_REAL";
+    case SQL_CHAR:                              return "SQL_CHAR";
+    case SQL_VARCHAR:                           return "SQL_VARCHAR";
+    case SQL_LONGVARCHAR:                       return "SQL_LONGVARCHAR";
+    case SQL_WCHAR:                             return "SQL_WCHAR";
+    case SQL_WVARCHAR:                          return "SQL_WVARCHAR";
+    case SQL_WLONGVARCHAR:                      return "SQL_WLONGVARCHAR";
+    case SQL_BINARY:                            return "SQL_BINARY";
+    case SQL_VARBINARY:                         return "SQL_VARBINARY";
+    case SQL_LONGVARBINARY:                     return "SQL_LONGVARBINARY";
+    case SQL_DATE:                              return "SQL_DATE";
+    case SQL_TIME:                              return "SQL_TIME";
+    case SQL_TIMESTAMP:                         return "SQL_TIMESTAMP";
+    case SQL_TYPE_DATE:                         return "SQL_TYPE_DATE";
+    case SQL_TYPE_TIME:                         return "SQL_TYPE_TIME";
+    case SQL_TYPE_TIMESTAMP:                    return "SQL_TYPE_TIMESTAMP";
+    case SQL_INTERVAL_MONTH:                    return "SQL_INTERVAL_MONTH";
+    case SQL_INTERVAL_YEAR:                     return "SQL_INTERVAL_YEAR";
+    case SQL_INTERVAL_YEAR_TO_MONTH:            return "SQL_INTERVAL_YEAR_TO_MONTH";
+    case SQL_INTERVAL_DAY:                      return "SQL_INTERVAL_DAY";
+    case SQL_INTERVAL_HOUR:                     return "SQL_INTERVAL_HOUR";
+    case SQL_INTERVAL_MINUTE:                   return "SQL_INTERVAL_MINUTE";
+    case SQL_INTERVAL_SECOND:                   return "SQL_INTERVAL_SECOND";
+    case SQL_INTERVAL_DAY_TO_HOUR:              return "SQL_INTERVAL_DAY_TO_HOUR";
+    case SQL_INTERVAL_DAY_TO_MINUTE:            return "SQL_INTERVAL_DAY_TO_MINUTE";
+    case SQL_INTERVAL_DAY_TO_SECOND:            return "SQL_INTERVAL_DAY_TO_SECOND";
+    case SQL_INTERVAL_HOUR_TO_MINUTE:           return "SQL_INTERVAL_HOUR_TO_MINUTE";
+    case SQL_INTERVAL_HOUR_TO_SECOND:           return "SQL_INTERVAL_HOUR_TO_SECOND";
+    case SQL_INTERVAL_MINUTE_TO_SECOND:         return "SQL_INTERVAL_MINUTE_TO_SECOND";
+    case SQL_GUID:                              return "SQL_GUID";
+    default: return "UNKNOWN";
+  }
+}
+
+const char* sql_c_type(int type) {
+  switch (type) {
+    case SQL_C_CHAR:                  return "SQL_C_CHAR";
+    case SQL_C_WCHAR:                 return "SQL_C_WCHAR";
+    case SQL_C_SHORT:                 return "SQL_C_SHORT";
+    case SQL_C_SSHORT:                return "SQL_C_SSHORT";
+    case SQL_C_USHORT:                return "SQL_C_USHORT";
+    case SQL_C_LONG:                  return "SQL_C_LONG";
+    case SQL_C_SLONG:                 return "SQL_C_SLONG";
+    case SQL_C_ULONG:                 return "SQL_C_ULONG";
+    case SQL_C_FLOAT:                 return "SQL_C_FLOAT";
+    case SQL_C_DOUBLE:                return "SQL_C_DOUBLE";
+    case SQL_C_BIT:                   return "SQL_C_BIT";
+    case SQL_C_TINYINT:               return "SQL_C_TINYINT";
+    case SQL_C_STINYINT:              return "SQL_C_STINYINT";
+    case SQL_C_UTINYINT:              return "SQL_C_UTINYINT";
+    case SQL_C_SBIGINT:               return "SQL_C_SBIGINT";
+    case SQL_C_UBIGINT:               return "SQL_C_UBIGINT";
+    case SQL_C_BINARY:                return "SQL_C_BINARY";
+    case SQL_C_DATE:                  return "SQL_C_DATE";
+    case SQL_C_TIME:                  return "SQL_C_TIME";
+    case SQL_C_TIMESTAMP:             return "SQL_C_TIMESTAMP";
+    case SQL_C_TYPE_DATE:             return "SQL_C_TYPE_DATE";
+    case SQL_C_TYPE_TIME:             return "SQL_C_TYPE_TIME";
+    case SQL_C_TYPE_TIMESTAMP:        return "SQL_C_TYPE_TIMESTAMP";
+    case SQL_C_NUMERIC:               return "SQL_C_NUMERIC";
+    case SQL_C_GUID:                  return "SQL_C_GUID";
+    default: return "UNKNOWN";
+  }
+}
+
+int is_valid_sql_c_type(int type) {
+  const char *ctype = sql_c_type(type);
+  if (strcmp(ctype, "UNKNOWN")==0) return 0;
+  return 1;
+}
+
+int is_valid_sql_sql_type(int type) {
+  const char *sqltype = sql_sql_type(type);
+  if (strcmp(sqltype, "UNKNOWN")==0) return 0;
+  return 1;
+}
+
+int string_conv(const char *fromcode, const char *tocode,
+                const unsigned char *src, size_t sbytes,
+                unsigned char *dst, size_t dbytes,
+                size_t *consumed, size_t *generated)
+{
+  if (consumed) *consumed = 0;
+  if (generated) *generated = 0;
+
+  if (dbytes <= 0) return -1;
+  dst[0] = '\0';
+
+  iconv_t conv = iconv_open(tocode, fromcode);
+  if (!conv) return -1;
+
+  int r = 0;
+  do {
+    char *s = (char*)src;
+    char *d = (char*)dst;
+    size_t sl = sbytes;
+    size_t dl = dbytes;
+
+    r = iconv(conv, &s, &sl, &d, &dl);
+    *d = '\0';
+
+    if (consumed) *consumed = sbytes - sl;
+    if (generated) *generated = dbytes - dl;
+
+  } while (0);
+
+  iconv_close(conv);
+  return r;
+}
+
+int utf8_chars(const char *src)
+{
+  const char *fromcode = "UTF-8";
+  const char *tocode = "UCS-2LE";
+  iconv_t conv = iconv_open(tocode, fromcode);
+  if (!conv) return -1;
+
+  size_t slen = strlen(src);
+  char buf[4096];
+  size_t dlen = sizeof(buf);
+  char *ps = (char*)src;
+  char *pd = buf;
+  iconv(conv, &ps, &slen, &pd, &dlen);
+  DASSERT(slen==0);
+
+  size_t chars = (sizeof(buf) - dlen) / 2;
+  iconv_close(conv);
+  return chars;
+}
+
+unsigned char* utf8_to_ucs4le(const char *utf8, size_t *chars)
+{
+  const char *tocode = "UCS-4LE";
+  const char *fromcode = "UTF-8";
+
+  iconv_t conv = iconv_open(tocode, fromcode);
+  if (!conv) return NULL;
+
+  unsigned char *ucs4le = NULL;
+
+  do {
+    size_t slen = strlen(utf8);
+    size_t dlen = slen * 4;
+
+    ucs4le = (unsigned char*)malloc(dlen+1);
+    if (!ucs4le) break;
+
+    char *src = (char*)utf8;
+    char *dst = (char*)ucs4le;
+    size_t s = slen;
+    size_t d = dlen;
+    iconv(conv, &src, &s, &dst, &d);
+    dst[0] = '\0';
+
+    if (chars) *chars = (dlen - d) / 4;
+  } while (0);
+
+  iconv_close(conv);
+  return ucs4le;
+}
+
+char* ucs4le_to_utf8(const unsigned char *ucs4le, size_t slen, size_t *chars)
+{
+  const char *fromcode = "UCS-4LE";
+  const char *tocode = "UTF-8";
+
+  iconv_t conv = iconv_open(tocode, fromcode);
+  if (!conv) return NULL;
+
+  char *utf8 = NULL;
+
+  do {
+    size_t dlen = slen;
+
+    utf8 = (char*)malloc(dlen+1);
+    if (!utf8) break;
+
+    char *dst = utf8;
+    char *src = (char*)ucs4le;
+    size_t s = slen;
+    size_t d = dlen;
+    iconv(conv, &src, &s, &dst, &d);
+    dst[0] = '\0';
+
+    if (chars) *chars = (slen - s) / 4;
+  } while (0);
+
+  iconv_close(conv);
+  return utf8;
+}
+
+SQLCHAR* wchars_to_chars(const SQLWCHAR *wchars, size_t chs, size_t *bytes)
+{
+  size_t dlen = chs * 4;
+  SQLCHAR *dst = (SQLCHAR*)malloc(dlen + 1);
+  if (!dst) return NULL;
+
+  string_conv("UCS-2LE", "UTF-8", (const unsigned char*)wchars, chs * sizeof(*wchars), dst, dlen + 1, NULL, bytes);
+
+  return dst;
+}
+
--- a/src/connector/odbc/src/todbc_util.h
+++ b/src/connector/odbc/src/todbc_util.h
@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * 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/>.
+ */
+
+#ifndef _TODBC_UTIL_H_
+#define _TODBC_UTIL_H_
+
+#include <libgen.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sql.h>
+
+#define D(fmt, ...)                                              \
+  fprintf(stderr,                                                \
+          "%s[%d]:%s() " fmt "\n",                               \
+          basename((char*)__FILE__), __LINE__, __func__,         \
+          ##__VA_ARGS__)
+
+#define DASSERT(statement)                                       \
+do {                                                             \
+  if (statement) break;                                          \
+  D("Assertion failure: %s", #statement);                        \
+  abort();                                                       \
+} while (0)
+
+#define DASSERTX(statement, fmt, ...)                                \
+do {                                                                 \
+  if (statement) break;                                              \
+  D("Assertion failure: %s, " fmt "", #statement, ##__VA_ARGS__);    \
+  abort();                                                           \
+} while (0)
+
+
+
+const char* sql_sql_type(int type);
+const char* sql_c_type(int type);
+
+int is_valid_sql_c_type(int type);
+int is_valid_sql_sql_type(int type);
+
+int string_conv(const char *fromcode, const char *tocode,
+                const unsigned char *src, size_t sbytes,
+                unsigned char *dst, size_t dbytes,
+                size_t *consumed, size_t *generated);
+int utf8_chars(const char *src);
+
+unsigned char* utf8_to_ucs4le(const char *utf8, size_t *chars);
+char*          ucs4le_to_utf8(const unsigned char *ucs4le, size_t slen, size_t *chars);
+SQLCHAR*       wchars_to_chars(const SQLWCHAR *wchars, size_t chs, size_t *bytes);
+
+#endif // _TODBC_UTIL_H_
--- a/src/connector/odbc/tests/CMakeLists.txt
+++ b/src/connector/odbc/tests/CMakeLists.txt
@ -0,0 +1,7 @@
+PROJECT(TDengine)
+
+IF (TD_LINUX)
+  AUX_SOURCE_DIRECTORY(. SRC)
+  ADD_EXECUTABLE(tcodbc main.c)
+  TARGET_LINK_LIBRARIES(tcodbc odbc)
+ENDIF ()
--- a/src/connector/odbc/tests/main.c
+++ b/src/connector/odbc/tests/main.c
@ -0,0 +1,231 @@
+#include <sql.h>
+#include <sqlext.h>
+
+#include <stdio.h>
+#include <string.h>
+
+#include "os.h"
+
+// static const char *dsn = "TAOS_DSN";
+// static const char *uid = "root";
+// static const char *pwd = "taosdata";
+
+typedef struct data_s            data_t;
+struct data_s {
+  int64_t                 ts;
+  int8_t                  b;
+  int8_t                  v1;
+  int16_t                 v2;
+  int32_t                 v4;
+  int64_t                 v8;
+  float                   f4;
+  double                  f8;
+  char                    bin[40+1];
+  char                    blob[40+1]; // why 80?  ref: tests/examples/c/apitest.c
+};
+
+static const char *pre_stmts[] = {
+  "create database db",
+  "use db",
+  "create table t (ts timestamp, b bool, v1 tinyint, v2 smallint, v4 int, v8 bigint, f4 float, f8 double, bin binary(40), blob nchar(10))"
+};
+
+static const char *pro_stmts[] = {
+  // "insert into t values ('2019-07-15 00:00:00', 1)",
+  // "insert into t values ('2019-07-15 01:00:00', 2)",
+  "select * from t"
+  // "drop database db"
+};
+
+#define CHK_RESULT(r, ht, h)                                                    \
+do {                                                                            \
+  if (r==0) break;                                                              \
+  SQLCHAR      ss[10];                                                          \
+  SQLINTEGER   ne = 0;                                                          \
+  SQLCHAR      es[4096];                                                        \
+  SQLSMALLINT  n  = 0;                                                          \
+  ss[0] = '\0';                                                                 \
+  es[0] = '\0';                                                                 \
+  SQLRETURN ret = SQLGetDiagRec(ht, h, 1, ss, &ne, es, sizeof(es), &n);         \
+  if (ret) break;                                                               \
+  fprintf(stderr, "%s%s\n", ss, es);                                            \
+} while (0)
+
+static int do_statement(SQLHSTMT stmt, const char *statement) {
+  SQLRETURN r = 0;
+  do {
+    fprintf(stderr, "prepare [%s]\n", statement);
+    r = SQLPrepare(stmt, (SQLCHAR*)statement, strlen(statement));
+    CHK_RESULT(r, SQL_HANDLE_STMT, stmt);
+    if (r) break;
+    fprintf(stderr, "execute [%s]\n", statement);
+    r = SQLExecute(stmt);
+    CHK_RESULT(r, SQL_HANDLE_STMT, stmt);
+    if (r) break;
+    fprintf(stderr, "done\n");
+  } while (0);
+  fprintf(stderr, "r: [%x][%d]\n", r, r);
+  return r;
+}
+
+static int do_insert(SQLHSTMT stmt, data_t data) {
+  SQLRETURN r = 0;
+  SQLLEN 		lbin;
+  SQLLEN    lblob;
+
+  const char *statement = "insert into t values (?, ?, ?, ?, ?, ?, ?, ?, ?,?)";
+  int ignored = 0;
+
+  do {
+    fprintf(stderr, "prepare [%s]\n", statement);
+    r = SQLPrepare(stmt, (SQLCHAR*)statement, strlen(statement));
+    CHK_RESULT(r, SQL_HANDLE_STMT, stmt);
+    if (r) break;
+
+    fprintf(stderr, "bind 1 [%s]\n", statement);
+    r = SQLBindParameter(stmt, 1, SQL_PARAM_INPUT, SQL_C_SBIGINT, SQL_TIMESTAMP, ignored, ignored, &data.ts, ignored, NULL);
+    CHK_RESULT(r, SQL_HANDLE_STMT, stmt);
+    if (r) break;
+
+    fprintf(stderr, "bind 2 [%s]\n", statement);
+    r = SQLBindParameter(stmt, 2, SQL_PARAM_INPUT, SQL_C_BIT, SQL_BIT, ignored, ignored, &data.b, ignored, NULL);
+    CHK_RESULT(r, SQL_HANDLE_STMT, stmt);
+    if (r) break;
+
+    fprintf(stderr, "bind 3 [%s]\n", statement);
+    r = SQLBindParameter(stmt, 3, SQL_PARAM_INPUT, SQL_C_TINYINT, SQL_TINYINT, ignored, ignored, &data.v1, ignored, NULL);
+    CHK_RESULT(r, SQL_HANDLE_STMT, stmt);
+    if (r) break;
+
+    fprintf(stderr, "bind 4 [%s]\n", statement);
+    r = SQLBindParameter(stmt, 4, SQL_PARAM_INPUT, SQL_C_SHORT, SQL_SMALLINT, ignored, ignored, &data.v2, ignored, NULL);
+    CHK_RESULT(r, SQL_HANDLE_STMT, stmt);
+    if (r) break;
+
+    fprintf(stderr, "bind 5 [%s]\n", statement);
+    r = SQLBindParameter(stmt, 5, SQL_PARAM_INPUT, SQL_C_LONG, SQL_INTEGER, ignored, ignored, &data.v4, ignored, NULL);
+    CHK_RESULT(r, SQL_HANDLE_STMT, stmt);
+    if (r) break;
+
+    fprintf(stderr, "bind 6 [%s]\n", statement);
+    r = SQLBindParameter(stmt, 6, SQL_PARAM_INPUT, SQL_C_SBIGINT, SQL_BIGINT, ignored, ignored, &data.v8, ignored, NULL);
+    CHK_RESULT(r, SQL_HANDLE_STMT, stmt);
+    if (r) break;
+
+    fprintf(stderr, "bind 7 [%s]\n", statement);
+    r = SQLBindParameter(stmt, 7, SQL_PARAM_INPUT, SQL_C_FLOAT, SQL_FLOAT, ignored, ignored, &data.f4, ignored, NULL);
+    CHK_RESULT(r, SQL_HANDLE_STMT, stmt);
+    if (r) break;
+
+    fprintf(stderr, "bind 8 [%s]\n", statement);
+    r = SQLBindParameter(stmt, 8, SQL_PARAM_INPUT, SQL_C_DOUBLE, SQL_DOUBLE, ignored, ignored, &data.f8, ignored, NULL);
+    CHK_RESULT(r, SQL_HANDLE_STMT, stmt);
+    if (r) break;
+
+    fprintf(stderr, "bind 9 [%s]\n", statement);
+    lbin = SQL_NTS;
+    r = SQLBindParameter(stmt, 9, SQL_PARAM_INPUT, SQL_C_BINARY, SQL_VARBINARY, sizeof(data.bin)-1, ignored, &data.bin, ignored, &lbin);
+    CHK_RESULT(r, SQL_HANDLE_STMT, stmt);
+    if (r) break;
+
+    fprintf(stderr, "bind 10 [%s]\n", statement);
+    lblob = SQL_NTS;
+    r = SQLBindParameter(stmt, 10, SQL_PARAM_INPUT, SQL_C_CHAR, SQL_VARCHAR, sizeof(data.blob)-1, ignored, &data.blob, ignored, &lblob);
+    CHK_RESULT(r, SQL_HANDLE_STMT, stmt);
+    if (r) break;
+
+    fprintf(stderr, "execute [%s]\n", statement);
+    r = SQLExecute(stmt);
+    CHK_RESULT(r, SQL_HANDLE_STMT, stmt);
+    if (r) break;
+
+    // ts += 1;
+    // v  = 2;
+    // fprintf(stderr, "execute [%s]\n", statement);
+    // r = SQLExecute(stmt);
+    // if (r) break;
+
+    fprintf(stderr, "done\n");
+  } while (0);
+  fprintf(stderr, "r: [%x][%d]\n", r, r);
+  return r;
+}
+
+int main(int argc, char *argv[]) {
+  if (argc < 4) return 1;
+  const char *dsn = argv[1];
+  const char *uid = argv[2];
+  const char *pwd = argv[3];
+  SQLRETURN r;
+  SQLHENV env = {0};
+  SQLHDBC conn = {0};
+  r = SQLAllocEnv(&env);
+  if (r!=SQL_SUCCESS) return 1;
+  do {
+    r = SQLAllocConnect(env, &conn);
+    CHK_RESULT(r, SQL_HANDLE_ENV, env);
+    if (r!=SQL_SUCCESS) break;
+    do {
+      r = SQLConnect(conn, (SQLCHAR*)dsn, strlen(dsn),
+                           (SQLCHAR*)uid, strlen(uid),
+                           (SQLCHAR*)pwd, strlen(pwd));
+      CHK_RESULT(r, SQL_HANDLE_DBC, conn);
+      if (r!=SQL_SUCCESS) break;
+      do {
+        SQLHSTMT stmt = {0};
+        r = SQLAllocHandle(SQL_HANDLE_STMT, conn, &stmt);
+        if (r!=SQL_SUCCESS) break;
+        do {
+          do_statement(stmt, "drop database db");
+          for (size_t i=0; i<sizeof(pre_stmts)/sizeof(pre_stmts[0]); ++i) {
+            r = do_statement(stmt, pre_stmts[i]);
+            if (r!=SQL_SUCCESS) break;
+          }
+          do {
+            data_t       data = {0};
+            data.ts      = 1591060628001;
+            data.b       = 1;
+            data.v1      = 127;
+            data.v2      = 32767;
+            data.v4      = 2147483647;
+            data.v8      = 9223372036854775807;
+            data.f4      = 123.456;
+            data.f8      = 9999999.999999;
+            memset(data.bin, 0, sizeof(data.bin));
+            memset(data.blob, 0, sizeof(data.blob));
+            snprintf(data.bin, sizeof(data.bin), "hel我lo");
+            snprintf(data.blob, sizeof(data.blob), "world");
+            snprintf(data.blob, sizeof(data.blob), "wo人rld");
+            SQLHSTMT stmt = {0};
+            r = SQLAllocHandle(SQL_HANDLE_STMT, conn, &stmt);
+            if (r!=SQL_SUCCESS) break;
+            do {
+              r = do_insert(stmt, data);
+              if (r!=SQL_SUCCESS) break;
+            } while (0);
+            SQLFreeHandle(SQL_HANDLE_STMT, stmt);
+
+            // r = SQLAllocHandle(SQL_HANDLE_STMT, conn, &stmt);
+            // if (r!=SQL_SUCCESS) break;
+            // do {
+            //   r = do_insert(stmt, ts++, v++);
+            //   if (r!=SQL_SUCCESS) break;
+            // } while (0);
+            // SQLFreeHandle(SQL_HANDLE_STMT, stmt);
+          } while (0);
+          if (r!=SQL_SUCCESS) break;
+          for (size_t i=0; i<sizeof(pro_stmts)/sizeof(pro_stmts[0]); ++i) {
+            r = do_statement(stmt, pro_stmts[i]);
+            if (r!=SQL_SUCCESS) break;
+          }
+        } while (0);
+        SQLFreeHandle(SQL_HANDLE_STMT, stmt);
+      } while (0);
+      SQLDisconnect(conn);
+    } while (0);
+    SQLFreeConnect(conn);
+  } while (0);
+  SQLFreeEnv(env);
+  return r ? 1 : 0;
+}
+
--- a/src/connector/odbc/tests/odbc.py
+++ b/src/connector/odbc/tests/odbc.py
@ -0,0 +1,120 @@
+import pyodbc
+cnxn = pyodbc.connect('DSN=TAOS_DSN;UID=root;PWD=taosdata', autocommit=True)
+cnxn.setdecoding(pyodbc.SQL_CHAR, encoding='utf-8')
+#cnxn.setdecoding(pyodbc.SQL_WCHAR, encoding='utf-8')
+#cnxn.setencoding(encoding='utf-8')
+
+cursor = cnxn.cursor()
+cursor.execute("SELECT * from db.t")
+row = cursor.fetchone()
+while row:
+    print(row)
+    row = cursor.fetchone()
+cursor.close()
+
+#cursor = cnxn.cursor()
+#cursor.execute("""
+#INSERT INTO db.t values (?,?,?,?,?,?,?,?,?,?)
+#""",
+#"2020-12-12 00:00:00",
+#1,
+#27,
+#32767,
+#147483647,
+#223372036854775807,
+#23.456,
+#899.999999,
+#"foo",
+#"bar")
+
+cursor = cnxn.cursor()
+cursor.execute("drop database if exists db");
+cursor.close()
+
+cursor = cnxn.cursor()
+cursor.execute("create database db");
+cursor.close()
+
+cursor = cnxn.cursor()
+cursor.execute("create table db.t (ts timestamp, b bool, v1 tinyint, v2 smallint, v4 int, v8 bigint, f4 float, f8 double, bin binary(40), blob nchar(10))");
+cursor.close()
+
+cursor = cnxn.cursor()
+cursor.execute("insert into db.t values('2020-10-13 06:44:00', 1, 127, 32767, 32768, 32769, 123.456, 789.987, 'hello', 'world')")
+cursor.close()
+
+cursor = cnxn.cursor()
+cursor.execute("insert into db.t values(?,?,?,?,?,?,?,?,?,?)", "2020-10-13 07:06:00", 0, 127, 32767, 32768, 32769, 123.456, 789.987, "hel后lo", "wo哈rld");
+cursor.close()
+
+cursor = cnxn.cursor()
+cursor.execute("SELECT * from db.t")
+row = cursor.fetchone()
+while row:
+    print(row)
+    row = cursor.fetchone()
+cursor.close()
+
+cursor = cnxn.cursor()
+cursor.execute("drop database if exists db");
+cursor.close()
+
+cursor = cnxn.cursor()
+cursor.execute("create database db");
+cursor.close()
+
+cursor = cnxn.cursor()
+cursor.execute("create table db.t (ts timestamp, b bool, v1 tinyint, v2 smallint, v4 int, v8 bigint, f4 float, f8 double, bin binary(4), blob nchar(4))");
+cursor.close()
+
+cursor = cnxn.cursor()
+cursor.execute("insert into db.t values('2020-10-13 06:44:00', 1, 127, 32767, 32768, 32769, 123.456, 789.987, 'hell', 'worl')")
+cursor.close()
+
+cursor = cnxn.cursor()
+cursor.execute("SELECT * from db.t")
+row = cursor.fetchone()
+while row:
+    print(row)
+    row = cursor.fetchone()
+cursor.close()
+
+cursor = cnxn.cursor()
+cursor.execute("create table db.v (ts timestamp, v1 tinyint)")
+cursor.close()
+
+params = [ ('A', 1), ('B', 2), ('C', 3) ]
+params = [ ('A', 1), ('B', 2), ('C', 3) ]
+params = [ ('2020-10-16 00:00:00', 1),
+           ('2020-10-16 00:00:01', 4),
+           ('2020-10-16 00:00:02', 5),
+           ('2020-10-16 00:00:03.009', 6) ]
+cursor = cnxn.cursor()
+cursor.fast_executemany = True
+cursor.executemany("insert into db.v values (?, ?)", params)
+cursor.close()
+
+cursor = cnxn.cursor()
+cursor.execute("SELECT * from db.v")
+row = cursor.fetchone()
+while row:
+    print(row)
+    row = cursor.fetchone()
+cursor.close()
+
+cursor = cnxn.cursor()
+cursor.execute("SELECT * from db.v where v1 > ?", 4)
+row = cursor.fetchone()
+while row:
+    print(row)
+    row = cursor.fetchone()
+cursor.close()
+
+cursor = cnxn.cursor()
+cursor.execute("SELECT * from db.v where v1 > ?", '5')
+row = cursor.fetchone()
+while row:
+    print(row)
+    row = cursor.fetchone()
+cursor.close()
+
--- a/src/connector/python/linux/python2/taos/cinterface.py
+++ b/src/connector/python/linux/python2/taos/cinterface.py
@ -225,6 +225,7 @@ class CTaosInterface(object):

        if connection.value == None:
            print('connect to TDengine failed')
+            raise ConnectionError("connect to TDengine failed")
            # sys.exit(1)
        else:
            print('connect to TDengine success')
--- a/src/connector/python/linux/python2/taos/cursor.py
+++ b/src/connector/python/linux/python2/taos/cursor.py
@ -192,8 +192,10 @@ class TDengineCursor(object):
        buffer = [[] for i in range(len(self._fields))]
        self._rowcount = 0
        while True:
-            block, num_of_fields = CTaosInterface.fetchBlock(
-                self._result, self._fields)
+            block, num_of_fields = CTaosInterface.fetchBlock(self._result, self._fields)
+            errno = CTaosInterface.libtaos.taos_errno(self._result)
+            if errno != 0:
+                raise ProgrammingError(CTaosInterface.errStr(self._result), errno)
            if num_of_fields == 0:
                break
            self._rowcount += num_of_fields
--- a/src/connector/python/linux/python3/taos/cinterface.py
+++ b/src/connector/python/linux/python3/taos/cinterface.py
@ -225,6 +225,7 @@ class CTaosInterface(object):

        if connection.value == None:
            print('connect to TDengine failed')
+            raise ConnectionError("connect to TDengine failed")
            # sys.exit(1)
        #else:
        #    print('connect to TDengine success')
--- a/src/connector/python/linux/python3/taos/cursor.py
+++ b/src/connector/python/linux/python3/taos/cursor.py
@ -207,8 +207,10 @@ class TDengineCursor(object):
        buffer = [[] for i in range(len(self._fields))]
        self._rowcount = 0
        while True:
-            block, num_of_fields = CTaosInterface.fetchBlock(
-                self._result, self._fields)
+            block, num_of_fields = CTaosInterface.fetchBlock(self._result, self._fields)
+            errno = CTaosInterface.libtaos.taos_errno(self._result)
+            if errno != 0:
+                raise ProgrammingError(CTaosInterface.errStr(self._result), errno)
            if num_of_fields == 0:
                break
            self._rowcount += num_of_fields
--- a/src/connector/python/windows/python2/taos/cursor.py
+++ b/src/connector/python/windows/python2/taos/cursor.py
@ -142,6 +142,9 @@ class TDengineCursor(object):
        self._rowcount = 0
        while True:
            block, num_of_fields = CTaosInterface.fetchBlock(self._result, self._fields)
+            errno = CTaosInterface.libtaos.taos_errno(self._result)
+            if errno != 0:
+                raise ProgrammingError(CTaosInterface.errStr(self._result), errno)
            if num_of_fields == 0: break
            self._rowcount += num_of_fields
            for i in range(len(self._fields)):
--- a/src/connector/python/windows/python3/taos/cursor.py
+++ b/src/connector/python/windows/python3/taos/cursor.py
@ -142,6 +142,9 @@ class TDengineCursor(object):
        self._rowcount = 0
        while True:
            block, num_of_fields = CTaosInterface.fetchBlock(self._result, self._fields)
+            errno = CTaosInterface.libtaos.taos_errno(self._result)
+            if errno != 0:
+                raise ProgrammingError(CTaosInterface.errStr(self._result), errno)
            if num_of_fields == 0: break
            self._rowcount += num_of_fields
            for i in range(len(self._fields)):
--- a/src/dnode/CMakeLists.txt
+++ b/src/dnode/CMakeLists.txt
@ -4,6 +4,7 @@ PROJECT(TDengine)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/query/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/mnode/inc)
 INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/tsdb/inc)
+INCLUDE_DIRECTORIES(${TD_COMMUNITY_DIR}/src/sync/inc)
 INCLUDE_DIRECTORIES(${TD_ENTERPRISE_DIR}/src/inc)

 INCLUDE_DIRECTORIES(inc)
--- a/src/dnode/src/dnodeMPeer.c
+++ b/src/dnode/src/dnodeMPeer.c
@ -33,7 +33,8 @@ typedef struct {
 } SMPeerWorker;

 typedef struct {
-  int32_t       num;
+  int32_t curNum;
+  int32_t maxNum;
  SMPeerWorker *peerWorker;
 } SMPeerWorkerPool;

@ -46,37 +47,44 @@ static void *dnodeProcessMnodePeerQueue(void *param);
 int32_t dnodeInitMnodePeer() {
  tsMPeerQset = taosOpenQset();
  
-  tsMPeerPool.num = 1;
-  tsMPeerPool.peerWorker = (SMPeerWorker *)calloc(sizeof(SMPeerWorker), tsMPeerPool.num);
+  tsMPeerPool.maxNum = 1;
+  tsMPeerPool.curNum = 0;
+  tsMPeerPool.peerWorker = (SMPeerWorker *)calloc(sizeof(SMPeerWorker), tsMPeerPool.maxNum);

  if (tsMPeerPool.peerWorker == NULL) return -1;
-  for (int32_t i = 0; i < tsMPeerPool.num; ++i) {
+  for (int32_t i = 0; i < tsMPeerPool.maxNum; ++i) {
    SMPeerWorker *pWorker = tsMPeerPool.peerWorker + i;
    pWorker->workerId = i;
+    dDebug("dnode mpeer worker:%d is created", i);
  }

-  dInfo("dnode mpeer is opened");
+  dDebug("dnode mpeer is opened, workers:%d qset:%p", tsMPeerPool.maxNum, tsMPeerQset);
  return 0;
 }

 void dnodeCleanupMnodePeer() {
-  for (int32_t i = 0; i < tsMPeerPool.num; ++i) {
+  for (int32_t i = 0; i < tsMPeerPool.maxNum; ++i) {
    SMPeerWorker *pWorker = tsMPeerPool.peerWorker + i;
    if (pWorker->thread) {
      taosQsetThreadResume(tsMPeerQset);
    }
+    dDebug("dnode mpeer worker:%d is closed", i);
  }

-  for (int32_t i = 0; i < tsMPeerPool.num; ++i) {
+  for (int32_t i = 0; i < tsMPeerPool.maxNum; ++i) {
    SMPeerWorker *pWorker = tsMPeerPool.peerWorker + i;
+    dDebug("dnode mpeer worker:%d start to join", i);
    if (pWorker->thread) {
      pthread_join(pWorker->thread, NULL);
    }
+    dDebug("dnode mpeer worker:%d join success", i);
  }

+  dDebug("dnode mpeer is closed, qset:%p", tsMPeerQset);
+
  taosCloseQset(tsMPeerQset);
+  tsMPeerQset = NULL;
  taosTFree(tsMPeerPool.peerWorker);
-  dInfo("dnode mpeer is closed");
 }

 int32_t dnodeAllocateMnodePqueue() {
@ -85,7 +93,7 @@ int32_t dnodeAllocateMnodePqueue() {

  taosAddIntoQset(tsMPeerQset, tsMPeerQueue, NULL);

-  for (int32_t i = 0; i < tsMPeerPool.num; ++i) {
+  for (int32_t i = tsMPeerPool.curNum; i < tsMPeerPool.maxNum; ++i) {
    SMPeerWorker *pWorker = tsMPeerPool.peerWorker + i;
    pWorker->workerId = i;

@ -98,7 +106,9 @@ int32_t dnodeAllocateMnodePqueue() {
    }

    pthread_attr_destroy(&thAttr);
-    dDebug("dnode mpeer worker:%d is launched, total:%d", pWorker->workerId, tsMPeerPool.num);
+
+    tsMPeerPool.curNum = i + 1;
+    dDebug("dnode mpeer worker:%d is launched, total:%d", pWorker->workerId, tsMPeerPool.maxNum);
  }

  dDebug("dnode mpeer queue:%p is allocated", tsMPeerQueue);
@ -106,6 +116,7 @@ int32_t dnodeAllocateMnodePqueue() {
 }

 void dnodeFreeMnodePqueue() {
+  dDebug("dnode mpeer queue:%p is freed", tsMPeerQueue);
  taosCloseQueue(tsMPeerQueue);
  tsMPeerQueue = NULL;
 }
@ -148,7 +159,7 @@ static void *dnodeProcessMnodePeerQueue(void *param) {
  
  while (1) {
    if (taosReadQitemFromQset(tsMPeerQset, &type, (void **)&pPeerMsg, &unUsed) == 0) {
-      dDebug("dnodeProcessMnodePeerQueue: got no message from qset, exiting...");
+      dDebug("qset:%p, mnode peer got no message from qset, exiting", tsMPeerQset);
      break;
    }

--- a/src/dnode/src/dnodeMRead.c
+++ b/src/dnode/src/dnodeMRead.c
@ -33,7 +33,8 @@ typedef struct {
 } SMReadWorker;

 typedef struct {
-  int32_t       num;
+  int32_t curNum;
+  int32_t maxNum;
  SMReadWorker *readWorker;
 } SMReadWorkerPool;

@ -46,40 +47,46 @@ static void *dnodeProcessMnodeReadQueue(void *param);
 int32_t dnodeInitMnodeRead() {
  tsMReadQset = taosOpenQset();

-  tsMReadPool.num = tsNumOfCores * tsNumOfThreadsPerCore / 2;
-  tsMReadPool.num = MAX(2, tsMReadPool.num);
-  tsMReadPool.num = MIN(4, tsMReadPool.num);
-  tsMReadPool.readWorker = (SMReadWorker *)calloc(sizeof(SMReadWorker), tsMReadPool.num);
+  tsMReadPool.maxNum = tsNumOfCores * tsNumOfThreadsPerCore / 2;
+  tsMReadPool.maxNum = MAX(2, tsMReadPool.maxNum);
+  tsMReadPool.maxNum = MIN(4, tsMReadPool.maxNum);
+  tsMReadPool.curNum = 0;
+  tsMReadPool.readWorker = (SMReadWorker *)calloc(sizeof(SMReadWorker), tsMReadPool.maxNum);

  if (tsMReadPool.readWorker == NULL) return -1;
-  for (int32_t i = 0; i < tsMReadPool.num; ++i) {
+  for (int32_t i = 0; i < tsMReadPool.maxNum; ++i) {
    SMReadWorker *pWorker = tsMReadPool.readWorker + i;
    pWorker->workerId = i;
+    dDebug("dnode mread worker:%d is created", i);
  }

-  dInfo("dnode mread is opened");
+  dDebug("dnode mread is opened, workers:%d qset:%p", tsMReadPool.maxNum, tsMReadQset);
  return 0;
 }

 void dnodeCleanupMnodeRead() {
-  for (int32_t i = 0; i < tsMReadPool.num; ++i) {
+  for (int32_t i = 0; i < tsMReadPool.maxNum; ++i) {
    SMReadWorker *pWorker = tsMReadPool.readWorker + i;
    if (pWorker->thread) {
      taosQsetThreadResume(tsMReadQset);
    }
+    dDebug("dnode mread worker:%d is closed", i);
  }

-  for (int32_t i = 0; i < tsMReadPool.num; ++i) {
+  for (int32_t i = 0; i < tsMReadPool.maxNum; ++i) {
    SMReadWorker *pWorker = tsMReadPool.readWorker + i;
+    dDebug("dnode mread worker:%d start to join", i);
    if (pWorker->thread) {
      pthread_join(pWorker->thread, NULL);
    }
+    dDebug("dnode mread worker:%d start to join", i);
  }

-  taosCloseQset(tsMReadQset);
-  free(tsMReadPool.readWorker);
+  dDebug("dnode mread is closed, qset:%p", tsMReadQset);

-  dInfo("dnode mread is closed");
+  taosCloseQset(tsMReadQset);
+  tsMReadQset = NULL;
+  free(tsMReadPool.readWorker);
 }

 int32_t dnodeAllocateMnodeRqueue() {
@ -88,7 +95,7 @@ int32_t dnodeAllocateMnodeRqueue() {

  taosAddIntoQset(tsMReadQset, tsMReadQueue, NULL);

-  for (int32_t i = 0; i < tsMReadPool.num; ++i) {
+  for (int32_t i = tsMReadPool.curNum; i < tsMReadPool.maxNum; ++i) {
    SMReadWorker *pWorker = tsMReadPool.readWorker + i;
    pWorker->workerId = i;

@ -101,7 +108,8 @@ int32_t dnodeAllocateMnodeRqueue() {
    }

    pthread_attr_destroy(&thAttr);
-    dDebug("dnode mread worker:%d is launched, total:%d", pWorker->workerId, tsMReadPool.num);
+    tsMReadPool.curNum = i + 1;
+    dDebug("dnode mread worker:%d is launched, total:%d", pWorker->workerId, tsMReadPool.maxNum);
  }

  dDebug("dnode mread queue:%p is allocated", tsMReadQueue);
@ -109,6 +117,7 @@ int32_t dnodeAllocateMnodeRqueue() {
 }

 void dnodeFreeMnodeRqueue() {
+  dDebug("dnode mread queue:%p is freed", tsMReadQueue);
  taosCloseQueue(tsMReadQueue);
  tsMReadQueue = NULL;
 }
@ -156,7 +165,7 @@ static void *dnodeProcessMnodeReadQueue(void *param) {
  
  while (1) {
    if (taosReadQitemFromQset(tsMReadQset, &type, (void **)&pReadMsg, &unUsed) == 0) {
-      dDebug("dnodeProcessMnodeReadQueue: got no message from qset, exiting...");
+      dDebug("qset:%p, mnode read got no message from qset, exiting", tsMReadQset);
      break;
    }

--- a/src/dnode/src/dnodeMWrite.c
+++ b/src/dnode/src/dnodeMWrite.c
@ -34,7 +34,8 @@ typedef struct {
 } SMWriteWorker;

 typedef struct {
-  int32_t        num;
+  int32_t curNum;
+  int32_t maxNum;
  SMWriteWorker *writeWorker;
 } SMWriteWorkerPool;

@ -48,37 +49,44 @@ static void *dnodeProcessMnodeWriteQueue(void *param);
 int32_t dnodeInitMnodeWrite() {
  tsMWriteQset = taosOpenQset();

-  tsMWritePool.num = 1;
-  tsMWritePool.writeWorker = (SMWriteWorker *)calloc(sizeof(SMWriteWorker), tsMWritePool.num);
+  tsMWritePool.maxNum = 1;
+  tsMWritePool.curNum = 0;
+  tsMWritePool.writeWorker = (SMWriteWorker *)calloc(sizeof(SMWriteWorker), tsMWritePool.maxNum);

  if (tsMWritePool.writeWorker == NULL) return -1;
-  for (int32_t i = 0; i < tsMWritePool.num; ++i) {
+  for (int32_t i = 0; i < tsMWritePool.maxNum; ++i) {
    SMWriteWorker *pWorker = tsMWritePool.writeWorker + i;
    pWorker->workerId = i;
+    dDebug("dnode mwrite worker:%d is created", i);
  }

-  dInfo("dnode mwrite is opened");
+  dDebug("dnode mwrite is opened, workers:%d qset:%p", tsMWritePool.maxNum, tsMWriteQset);
  return 0;
 }

 void dnodeCleanupMnodeWrite() {
-  for (int32_t i = 0; i < tsMWritePool.num; ++i) {
+  for (int32_t i = 0; i < tsMWritePool.maxNum; ++i) {
    SMWriteWorker *pWorker = tsMWritePool.writeWorker + i;
    if (pWorker->thread) {
      taosQsetThreadResume(tsMWriteQset);
    }
+    dDebug("dnode mwrite worker:%d is closed", i);
  }

-  for (int32_t i = 0; i < tsMWritePool.num; ++i) {
+  for (int32_t i = 0; i < tsMWritePool.maxNum; ++i) {
    SMWriteWorker *pWorker = tsMWritePool.writeWorker + i;
+    dDebug("dnode mwrite worker:%d start to join", i);
    if (pWorker->thread) {
      pthread_join(pWorker->thread, NULL);
    }
+    dDebug("dnode mwrite worker:%d join success", i);
  }

+  dDebug("dnode mwrite is closed, qset:%p", tsMWriteQset);
+
  taosCloseQset(tsMWriteQset);
+  tsMWriteQset = NULL;
  taosTFree(tsMWritePool.writeWorker);
-  dInfo("dnode mwrite is closed");
 }

 int32_t dnodeAllocateMnodeWqueue() {
@ -87,7 +95,7 @@ int32_t dnodeAllocateMnodeWqueue() {

  taosAddIntoQset(tsMWriteQset, tsMWriteQueue, NULL);

-  for (int32_t i = 0; i < tsMWritePool.num; ++i) {
+  for (int32_t i = tsMWritePool.curNum; i < tsMWritePool.maxNum; ++i) {
    SMWriteWorker *pWorker = tsMWritePool.writeWorker + i;
    pWorker->workerId = i;

@ -100,7 +108,8 @@ int32_t dnodeAllocateMnodeWqueue() {
    }

    pthread_attr_destroy(&thAttr);
-    dDebug("dnode mwrite worker:%d is launched, total:%d", pWorker->workerId, tsMWritePool.num);
+    tsMWritePool.curNum = i + 1;
+    dDebug("dnode mwrite worker:%d is launched, total:%d", pWorker->workerId, tsMWritePool.maxNum);
  }

  dDebug("dnode mwrite queue:%p is allocated", tsMWriteQueue);
@ -108,6 +117,7 @@ int32_t dnodeAllocateMnodeWqueue() {
 }

 void dnodeFreeMnodeWqueue() {
+  dDebug("dnode mwrite queue:%p is freed", tsMWriteQueue);
  taosCloseQueue(tsMWriteQueue);
  tsMWriteQueue = NULL;
 }
@ -122,11 +132,15 @@ void dnodeDispatchToMnodeWriteQueue(SRpcMsg *pMsg) {
  SMnodeMsg *pWrite = (SMnodeMsg *)taosAllocateQitem(sizeof(SMnodeMsg));
  mnodeCreateMsg(pWrite, pMsg);

-  dDebug("app:%p:%p, msg:%s is put into mwrite queue", pWrite->rpcMsg.ahandle, pWrite, taosMsg[pWrite->rpcMsg.msgType]);
+  dDebug("app:%p:%p, msg:%s is put into mwrite queue:%p", pWrite->rpcMsg.ahandle, pWrite,
+         taosMsg[pWrite->rpcMsg.msgType], tsMWriteQueue);
  taosWriteQitem(tsMWriteQueue, TAOS_QTYPE_RPC, pWrite);
 }

 static void dnodeFreeMnodeWriteMsg(SMnodeMsg *pWrite) {
+  dDebug("app:%p:%p, msg:%s is freed from mwrite queue:%p", pWrite->rpcMsg.ahandle, pWrite,
+         taosMsg[pWrite->rpcMsg.msgType], tsMWriteQueue);
+
  mnodeCleanupMsg(pWrite);
  taosFreeQitem(pWrite);
 }
@ -158,7 +172,7 @@ static void *dnodeProcessMnodeWriteQueue(void *param) {
  
  while (1) {
    if (taosReadQitemFromQset(tsMWriteQset, &type, (void **)&pWrite, &unUsed) == 0) {
-      dDebug("dnodeProcessMnodeWriteQueue: got no message from qset, exiting...");
+      dDebug("qset:%p, mnode write got no message from qset, exiting", tsMWriteQset);
      break;
    }

@ -182,8 +196,8 @@ void dnodeReprocessMnodeWriteMsg(void *pMsg) {
    dnodeSendRedirectMsg(pMsg, true);
    dnodeFreeMnodeWriteMsg(pWrite);
  } else {
-    dDebug("app:%p:%p, msg:%s is reput into mwrite queue, retry times:%d", pWrite->rpcMsg.ahandle, pWrite,
-           taosMsg[pWrite->rpcMsg.msgType], pWrite->retry);
+    dDebug("app:%p:%p, msg:%s is reput into mwrite queue:%p, retry times:%d", pWrite->rpcMsg.ahandle, pWrite,
+           taosMsg[pWrite->rpcMsg.msgType], tsMWriteQueue, pWrite->retry);

    taosWriteQitem(tsMWriteQueue, TAOS_QTYPE_RPC, pWrite);
  }
--- a/src/dnode/src/dnodeMgmt.c
+++ b/src/dnode/src/dnodeMgmt.c
@ -74,14 +74,16 @@ static int32_t  dnodeProcessAlterVnodeMsg(SRpcMsg *pMsg);
 static int32_t  dnodeProcessDropVnodeMsg(SRpcMsg *pMsg);
 static int32_t  dnodeProcessAlterStreamMsg(SRpcMsg *pMsg);
 static int32_t  dnodeProcessConfigDnodeMsg(SRpcMsg *pMsg);
+static int32_t dnodeProcessCreateMnodeMsg(SRpcMsg *pMsg);
 static int32_t (*dnodeProcessMgmtMsgFp[TSDB_MSG_TYPE_MAX])(SRpcMsg *pMsg);

 int32_t dnodeInitMgmt() {
  dnodeProcessMgmtMsgFp[TSDB_MSG_TYPE_MD_CREATE_VNODE] = dnodeProcessCreateVnodeMsg;
-  dnodeProcessMgmtMsgFp[TSDB_MSG_TYPE_MD_ALTER_VNODE] = dnodeProcessAlterVnodeMsg;
+  dnodeProcessMgmtMsgFp[TSDB_MSG_TYPE_MD_ALTER_VNODE]  = dnodeProcessAlterVnodeMsg;
  dnodeProcessMgmtMsgFp[TSDB_MSG_TYPE_MD_DROP_VNODE]   = dnodeProcessDropVnodeMsg;
  dnodeProcessMgmtMsgFp[TSDB_MSG_TYPE_MD_ALTER_STREAM] = dnodeProcessAlterStreamMsg;
  dnodeProcessMgmtMsgFp[TSDB_MSG_TYPE_MD_CONFIG_DNODE] = dnodeProcessConfigDnodeMsg;
+  dnodeProcessMgmtMsgFp[TSDB_MSG_TYPE_MD_CREATE_MNODE] = dnodeProcessCreateMnodeMsg;

  dnodeAddClientRspHandle(TSDB_MSG_TYPE_DM_STATUS_RSP,  dnodeProcessStatusRsp);
  dnodeReadDnodeCfg();
@ -226,7 +228,7 @@ static void *dnodeProcessMgmtQueue(void *param) {

  while (1) {
    if (taosReadQitemFromQset(tsMgmtQset, &type, (void **) &pMsg, &handle) == 0) {
-      dDebug("dnode mgmt got no message from qset, exit ...");
+      dDebug("qset:%p, dnode mgmt got no message from qset, exit", tsMgmtQset);
      break;
    }

@ -451,10 +453,34 @@ static int32_t dnodeProcessAlterStreamMsg(SRpcMsg *pMsg) {
 }

 static int32_t dnodeProcessConfigDnodeMsg(SRpcMsg *pMsg) {
-  SMDCfgDnodeMsg *pCfg = (SMDCfgDnodeMsg *)pMsg->pCont;
+  SMDCfgDnodeMsg *pCfg = pMsg->pCont;
  return taosCfgDynamicOptions(pCfg->config);
 }

+static int32_t dnodeProcessCreateMnodeMsg(SRpcMsg *pMsg) {
+  SMDCreateMnodeMsg *pCfg = pMsg->pCont;
+  pCfg->dnodeId = htonl(pCfg->dnodeId);
+  if (pCfg->dnodeId != dnodeGetDnodeId()) {
+    dError("dnodeId:%d, in create mnode msg is not equal with saved dnodeId:%d", pCfg->dnodeId, dnodeGetDnodeId());
+    return TSDB_CODE_MND_DNODE_ID_NOT_CONFIGURED;
+  }
+
+  if (strcmp(pCfg->dnodeEp, tsLocalEp) != 0) {
+    dError("dnodeEp:%s, in create mnode msg is not equal with saved dnodeEp:%s", pCfg->dnodeEp, tsLocalEp);
+    return TSDB_CODE_MND_DNODE_EP_NOT_CONFIGURED;
+  }
+
+  dDebug("dnodeId:%d, create mnode msg is received from mnodes, numOfMnodes:%d", pCfg->dnodeId, pCfg->mnodes.nodeNum);
+  for (int i = 0; i < pCfg->mnodes.nodeNum; ++i) {
+    pCfg->mnodes.nodeInfos[i].nodeId = htonl(pCfg->mnodes.nodeInfos[i].nodeId);
+    dDebug("mnode index:%d, mnode:%d:%s", i, pCfg->mnodes.nodeInfos[i].nodeId, pCfg->mnodes.nodeInfos[i].nodeEp);
+  }
+
+  dnodeStartMnode(&pCfg->mnodes);
+
+  return TSDB_CODE_SUCCESS;
+}
+
 void dnodeUpdateMnodeEpSetForPeer(SRpcEpSet *pEpSet) {
  if (pEpSet->numOfEps <= 0) {
    dError("mnode EP list for peer is changed, but content is invalid, discard it");
@ -465,29 +491,6 @@ void dnodeUpdateMnodeEpSetForPeer(SRpcEpSet *pEpSet) {
  for (int i = 0; i < pEpSet->numOfEps; ++i) {
    pEpSet->port[i] -= TSDB_PORT_DNODEDNODE;
    dInfo("mnode index:%d %s:%u", i, pEpSet->fqdn[i], pEpSet->port[i]);
-
-    if (!mnodeIsRunning()) {
-      if (strcmp(pEpSet->fqdn[i], tsLocalFqdn) == 0 && pEpSet->port[i] == tsServerPort) {
-        dInfo("mnode index:%d %s:%u should work as mnode", i, pEpSet->fqdn[i], pEpSet->port[i]);
-        bool find = false;
-        for (int i = 0; i < tsDMnodeInfos.nodeNum; ++i) {
-          if (tsDMnodeInfos.nodeInfos[i].nodeId == dnodeGetDnodeId()) {
-            dInfo("localEp found in mnode infos");
-            find = true;
-            break;
-          }
-        }
-
-        if (!find) {
-          dInfo("localEp not found in mnode infos, will set into mnode infos");
-          tstrncpy(tsDMnodeInfos.nodeInfos[tsDMnodeInfos.nodeNum].nodeEp, tsLocalEp, TSDB_EP_LEN);
-          tsDMnodeInfos.nodeInfos[tsDMnodeInfos.nodeNum].nodeId = dnodeGetDnodeId();
-          tsDMnodeInfos.nodeNum++;
-        }
-
-        dnodeStartMnode();
-      }
-    }
  }

  tsDMnodeEpSet = *pEpSet;
@ -532,7 +535,9 @@ static void dnodeProcessStatusRsp(SRpcMsg *pMsg) {
  }

  vnodeSetAccess(pStatusRsp->vgAccess, pCfg->numOfVnodes);
-  dnodeProcessModuleStatus(pCfg->moduleStatus);
+
+  // will not set mnode in status msg
+  // dnodeProcessModuleStatus(pCfg->moduleStatus);
  dnodeUpdateDnodeCfg(pCfg);

  dnodeUpdateMnodeInfos(pMnodes);
@ -576,7 +581,7 @@ static void dnodeUpdateMnodeInfos(SDMMnodeInfos *pMnodes) {
  }

  dnodeSaveMnodeInfos();
-  sdbUpdateSync();
+  sdbUpdateAsync();
 }

 static bool dnodeReadMnodeInfos() {
--- a/src/dnode/src/dnodeModule.c
+++ b/src/dnode/src/dnodeModule.c
@ -146,7 +146,9 @@ void dnodeProcessModuleStatus(uint32_t moduleStatus) {
  }
 }

-bool dnodeStartMnode() {
+bool dnodeStartMnode(void *pMnodes) {
+  SDMMnodeInfos *mnodes = pMnodes;
+
  if (tsModuleStatus & (1 << TSDB_MOD_MNODE)) {
    dDebug("mnode module is already started, module status:%d", tsModuleStatus);
    return false;
@ -156,6 +158,7 @@ bool dnodeStartMnode() {
  dInfo("start mnode module, module status:%d, new status:%d", tsModuleStatus, moduleStatus);
  dnodeProcessModuleStatus(moduleStatus);

-  sdbUpdateSync();
+  sdbUpdateSync(mnodes);
+
  return true;
 }
--- a/src/dnode/src/dnodePeer.c
+++ b/src/dnode/src/dnodePeer.c
@ -48,6 +48,7 @@ int32_t dnodeInitServer() {
  dnodeProcessReqMsgFp[TSDB_MSG_TYPE_MD_DROP_VNODE]   = dnodeDispatchToMgmtQueue;
  dnodeProcessReqMsgFp[TSDB_MSG_TYPE_MD_ALTER_STREAM] = dnodeDispatchToMgmtQueue;
  dnodeProcessReqMsgFp[TSDB_MSG_TYPE_MD_CONFIG_DNODE] = dnodeDispatchToMgmtQueue;
+  dnodeProcessReqMsgFp[TSDB_MSG_TYPE_MD_CREATE_MNODE] = dnodeDispatchToMgmtQueue;

  dnodeProcessReqMsgFp[TSDB_MSG_TYPE_DM_CONFIG_TABLE] = dnodeDispatchToMnodePeerQueue;
  dnodeProcessReqMsgFp[TSDB_MSG_TYPE_DM_CONFIG_VNODE] = dnodeDispatchToMnodePeerQueue;
@ -170,8 +171,12 @@ void dnodeSendMsgToDnode(SRpcEpSet *epSet, SRpcMsg *rpcMsg) {
  rpcSendRequest(tsDnodeClientRpc, epSet, rpcMsg);
 }

-void dnodeSendMsgToDnodeRecv(SRpcMsg *rpcMsg, SRpcMsg *rpcRsp) {
+void dnodeSendMsgToMnodeRecv(SRpcMsg *rpcMsg, SRpcMsg *rpcRsp) {
  SRpcEpSet epSet = {0};
  dnodeGetMnodeEpSetForPeer(&epSet);
  rpcSendRecv(tsDnodeClientRpc, &epSet, rpcMsg, rpcRsp);
 }
+
+void dnodeSendMsgToDnodeRecv(SRpcMsg *rpcMsg, SRpcMsg *rpcRsp, SRpcEpSet *epSet) {
+  rpcSendRecv(tsDnodeClientRpc, epSet, rpcMsg, rpcRsp);
+}
--- a/src/dnode/src/dnodeShell.c
+++ b/src/dnode/src/dnodeShell.c
@ -156,7 +156,7 @@ static int dnodeRetrieveUserAuthInfo(char *user, char *spi, char *encrypt, char
  
  dDebug("user:%s, send auth msg to mnodes", user);
  SRpcMsg rpcRsp = {0};
-  dnodeSendMsgToDnodeRecv(&rpcMsg, &rpcRsp);
+  dnodeSendMsgToMnodeRecv(&rpcMsg, &rpcRsp);

  if (rpcRsp.code != 0) {
    dError("user:%s, auth msg received from mnodes, error:%s", user, tstrerror(rpcRsp.code));
@ -173,15 +173,15 @@ static int dnodeRetrieveUserAuthInfo(char *user, char *spi, char *encrypt, char
  return rpcRsp.code;
 }

-void *dnodeSendCfgTableToRecv(int32_t vgId, int32_t sid) {
-  dDebug("vgId:%d, sid:%d send config table msg to mnode", vgId, sid);
+void *dnodeSendCfgTableToRecv(int32_t vgId, int32_t tid) {
+  dDebug("vgId:%d, tid:%d send config table msg to mnode", vgId, tid);

  int32_t contLen = sizeof(SDMConfigTableMsg);
  SDMConfigTableMsg *pMsg = rpcMallocCont(contLen);

  pMsg->dnodeId = htonl(dnodeGetDnodeId());
  pMsg->vgId = htonl(vgId);
-  pMsg->sid = htonl(sid);
+  pMsg->tid = htonl(tid);

  SRpcMsg rpcMsg = {0};
  rpcMsg.pCont = pMsg;
@ -189,23 +189,23 @@ void *dnodeSendCfgTableToRecv(int32_t vgId, int32_t sid) {
  rpcMsg.msgType = TSDB_MSG_TYPE_DM_CONFIG_TABLE;

  SRpcMsg rpcRsp = {0};
-  dnodeSendMsgToDnodeRecv(&rpcMsg, &rpcRsp);
+  dnodeSendMsgToMnodeRecv(&rpcMsg, &rpcRsp);
  terrno = rpcRsp.code;
  
  if (rpcRsp.code != 0) {
    rpcFreeCont(rpcRsp.pCont);
-    dError("vgId:%d, sid:%d failed to config table from mnode", vgId, sid);
+    dError("vgId:%d, tid:%d failed to config table from mnode", vgId, tid);
    return NULL;
  } else {
-    dInfo("vgId:%d, sid:%d config table msg is received", vgId, sid);
+    dInfo("vgId:%d, tid:%d config table msg is received", vgId, tid);
    
    // delete this after debug finished
    SMDCreateTableMsg *pTable = rpcRsp.pCont;
    int16_t   numOfColumns = htons(pTable->numOfColumns);
    int16_t   numOfTags = htons(pTable->numOfTags);
-    int32_t   sid = htonl(pTable->sid);
+    int32_t   tableId = htonl(pTable->tid);
    uint64_t  uid = htobe64(pTable->uid);
-    dInfo("table:%s, numOfColumns:%d numOfTags:%d sid:%d uid:%" PRIu64, pTable->tableId, numOfColumns, numOfTags, sid, uid);
+    dInfo("table:%s, numOfColumns:%d numOfTags:%d tid:%d uid:%" PRIu64, pTable->tableId, numOfColumns, numOfTags, tableId, uid);

    return rpcRsp.pCont;
  }
--- a/src/dnode/src/dnodeTelemetry.c
+++ b/src/dnode/src/dnodeTelemetry.c
@ -178,6 +178,7 @@ static void addVersionInfo(SBufferWriter* bw) {
  addStringField(bw, "version", version);
  addStringField(bw, "buildInfo", buildinfo);
  addStringField(bw, "gitInfo", gitinfo);  
+  addStringField(bw, "email", tsEmail);  
 }

 static void addRuntimeInfo(SBufferWriter* bw) {
@ -261,11 +262,27 @@ static void* telemetryThread(void* param) {
  return NULL;
 }

+static void dnodeGetEmail(char* filepath) {
+  int fd = open(filepath, O_RDONLY);
+  if (fd < 0) {
+    return;
+  }
+  
+  if (taosTRead(fd, (void *)tsEmail, TSDB_FQDN_LEN) < 0) {
+    dError("failed to read %d bytes from file %s since %s", TSDB_FQDN_LEN, filepath, strerror(errno));
+  } 
+
+  close(fd);   
+}
+
+
 int32_t dnodeInitTelemetry() {
  if (!tsEnableTelemetryReporting) {
    return 0;
  }

+  dnodeGetEmail("/usr/local/taos/email");  
+
  if (tsem_init(&tsExitSem, 0, 0) == -1) {
    // just log the error, it is ok for telemetry to fail
    dTrace("failed to create semaphore for telemetry, reason:%s", strerror(errno));
--- a/src/dnode/src/dnodeVRead.c
+++ b/src/dnode/src/dnodeVRead.c
@ -189,7 +189,6 @@ void dnodeSendRpcReadRsp(void *pVnode, SReadMsg *pRead, int32_t code) {
 void dnodeDispatchNonRspMsg(void *pVnode, SReadMsg *pRead, int32_t code) {
  rpcFreeCont(pRead->rpcMsg.pCont);
  vnodeRelease(pVnode);
-  return;
 }

 static void *dnodeProcessReadQueue(void *param) {
@ -199,7 +198,7 @@ static void *dnodeProcessReadQueue(void *param) {

  while (1) {
    if (taosReadQitemFromQset(readQset, &type, (void **)&pReadMsg, &pVnode) == 0) {
-      dDebug("dnodeProcessReadQueee: got no message from qset, exiting...");
+      dDebug("qset:%p dnode read got no message from qset, exiting", readQset);
      break;
    }

@ -213,7 +212,8 @@ static void *dnodeProcessReadQueue(void *param) {
    } else {
      if (code == TSDB_CODE_QRY_HAS_RSP) {
        dnodeSendRpcReadRsp(pVnode, pReadMsg, pReadMsg->rpcMsg.code);
-      } else { // code == TSDB_CODE_NOT_READY, do not return msg to client
+      } else { // code == TSDB_CODE_QRY_NOT_READY, do not return msg to client
+        assert(pReadMsg->rpcMsg.handle == NULL || (pReadMsg->rpcMsg.handle != NULL && pReadMsg->rpcMsg.msgType == 5));
        dnodeDispatchNonRspMsg(pVnode, pReadMsg, code);
      }
    }
--- a/src/dnode/src/dnodeVWrite.c
+++ b/src/dnode/src/dnodeVWrite.c
@ -24,8 +24,10 @@
 #include "twal.h"
 #include "tdataformat.h"
 #include "tglobal.h"
+#include "tsync.h"
 #include "vnode.h"
 #include "dnodeInt.h"
+#include "syncInt.h"
 #include "dnodeVWrite.h"
 #include "dnodeMgmt.h"

@ -210,19 +212,19 @@ void dnodeSendRpcVnodeWriteRsp(void *pVnode, void *param, int32_t code) {

 static void *dnodeProcessWriteQueue(void *param) {
  SWriteWorker *pWorker = (SWriteWorker *)param;
-  SWriteMsg    *pWrite;
-  SWalHead     *pHead;
+  SWriteMsg *   pWrite;
+  SWalHead *    pHead;
  int32_t       numOfMsgs;
  int           type;
-  void         *pVnode, *item;
-  SRspRet      *pRspRet;
+  void *        pVnode, *item;
+  SRspRet *     pRspRet;

  dDebug("write worker:%d is running", pWorker->workerId);

  while (1) {
    numOfMsgs = taosReadAllQitemsFromQset(pWorker->qset, pWorker->qall, &pVnode);
    if (numOfMsgs == 0) {
-      dDebug("dnodeProcessWriteQueee: got no message from qset, exiting...");
+      dDebug("qset:%p, dnode write got no message from qset, exiting", pWorker->qset);
      break;
    }

@ -237,13 +239,22 @@ static void *dnodeProcessWriteQueue(void *param) {
        pHead->msgType = pWrite->rpcMsg.msgType;
        pHead->version = 0;
        pHead->len = pWrite->contLen;
-        dDebug("%p, rpc msg:%s will be processed in vwrite queue", pWrite->rpcMsg.ahandle, taosMsg[pWrite->rpcMsg.msgType]);
+        dDebug("%p, rpc msg:%s will be processed in vwrite queue", pWrite->rpcMsg.ahandle,
+               taosMsg[pWrite->rpcMsg.msgType]);
+      } else if (type == TAOS_QTYPE_CQ) {
+        pHead = (SWalHead *)((char*)item + sizeof(SSyncHead));
+        dTrace("%p, CQ wal msg:%s will be processed in vwrite queue, version:%" PRIu64, pHead, taosMsg[pHead->msgType],
+               pHead->version);
      } else {
        pHead = (SWalHead *)item;
-        dTrace("%p, wal msg:%s will be processed in vwrite queue, version:%" PRIu64, pHead, taosMsg[pHead->msgType], pHead->version);
+        dTrace("%p, wal msg:%s will be processed in vwrite queue, version:%" PRIu64, pHead, taosMsg[pHead->msgType],
+               pHead->version);
      }

      int32_t code = vnodeProcessWrite(pVnode, type, pHead, pRspRet);
+      dTrace("%p, msg:%s is processed in vwrite queue, version:%" PRIu64 ", result:%s", pHead, taosMsg[pHead->msgType],
+             pHead->version, tstrerror(code));
+
      if (pWrite) {
        pWrite->rpcMsg.code = code;
        if (code <= 0) pWrite->processedCount = 1;
@ -279,13 +290,13 @@ static void dnodeHandleIdleWorker(SWriteWorker *pWorker) {
  int32_t num = taosGetQueueNumber(pWorker->qset);

  if (num > 0) {
-     usleep(30000);
-     sched_yield();
+    usleep(30000);
+    sched_yield();
  } else {
-     taosFreeQall(pWorker->qall);
-     taosCloseQset(pWorker->qset);
-     pWorker->qset = NULL;
-     dDebug("write worker:%d is released", pWorker->workerId);
-     pthread_exit(NULL);
+    taosFreeQall(pWorker->qall);
+    taosCloseQset(pWorker->qset);
+    pWorker->qset = NULL;
+    dDebug("write worker:%d is released", pWorker->workerId);
+    pthread_exit(NULL);
  }
 }
--- a/src/inc/dnode.h
+++ b/src/inc/dnode.h
@ -43,12 +43,13 @@ void    dnodeGetMnodeEpSetForPeer(void *epSet);
 void    dnodeGetMnodeEpSetForShell(void *epSet);
 void *  dnodeGetMnodeInfos();
 int32_t dnodeGetDnodeId();
-bool    dnodeStartMnode();
+bool    dnodeStartMnode(void *pModes);

 void  dnodeAddClientRspHandle(uint8_t msgType, void (*fp)(SRpcMsg *rpcMsg));
 void  dnodeSendMsgToDnode(SRpcEpSet *epSet, SRpcMsg *rpcMsg);
-void  dnodeSendMsgToDnodeRecv(SRpcMsg *rpcMsg, SRpcMsg *rpcRsp);
-void *dnodeSendCfgTableToRecv(int32_t vgId, int32_t sid);
+void  dnodeSendMsgToMnodeRecv(SRpcMsg *rpcMsg, SRpcMsg *rpcRsp);
+void  dnodeSendMsgToDnodeRecv(SRpcMsg *rpcMsg, SRpcMsg *rpcRsp, SRpcEpSet *epSet);
+void *dnodeSendCfgTableToRecv(int32_t vgId, int32_t tid);

 void *dnodeAllocateVnodeWqueue(void *pVnode);
 void  dnodeFreeVnodeWqueue(void *queue);
--- a/src/inc/mnode.h
+++ b/src/inc/mnode.h
@ -60,7 +60,8 @@ int32_t mnodeInitSystem();
 int32_t mnodeStartSystem();
 void    mnodeCleanupSystem();
 void    mnodeStopSystem();
-void    sdbUpdateSync();
+void    sdbUpdateAsync();
+void    sdbUpdateSync(void *pMnodes);
 bool    mnodeIsRunning();
 int32_t mnodeProcessRead(SMnodeMsg *pMsg);
 int32_t mnodeProcessWrite(SMnodeMsg *pMsg);
--- a/src/inc/taos.h
+++ b/src/inc/taos.h
@ -22,12 +22,12 @@
 extern "C" {
 #endif

-typedef void    TAOS;
-typedef void**  TAOS_ROW;
-typedef void    TAOS_RES;
-typedef void    TAOS_SUB;
-typedef void    TAOS_STREAM;
-typedef void    TAOS_STMT;
+typedef void   TAOS;
+typedef void   TAOS_STMT;
+typedef void   TAOS_RES;
+typedef void   TAOS_STREAM;
+typedef void   TAOS_SUB;
+typedef void **TAOS_ROW;

 // Data type definition
 #define TSDB_DATA_TYPE_NULL       0     // 1 bytes
@ -69,6 +69,8 @@ DLL_EXPORT int   taos_options(TSDB_OPTION option, const void *arg, ...);
 DLL_EXPORT TAOS *taos_connect(const char *ip, const char *user, const char *pass, const char *db, uint16_t port);
 DLL_EXPORT void  taos_close(TAOS *taos);

+const char *taos_data_type(int type);
+
 typedef struct TAOS_BIND {
  int            buffer_type;
  void *         buffer;
@ -77,10 +79,26 @@ typedef struct TAOS_BIND {
  int *          is_null;
  int            is_unsigned;  // unused
  int *          error;        // unused
+  union {
+    int64_t        ts;
+    int8_t         b;
+    int8_t         v1;
+    int16_t        v2;
+    int32_t        v4;
+    int64_t        v8;
+    float          f4;
+    double         f8;
+    unsigned char *bin;
+    char          *nchar;
+  } u;
+  unsigned int     allocated;
 } TAOS_BIND;

 TAOS_STMT *taos_stmt_init(TAOS *taos);
 int        taos_stmt_prepare(TAOS_STMT *stmt, const char *sql, unsigned long length);
+int        taos_stmt_is_insert(TAOS_STMT *stmt, int *insert);
+int        taos_stmt_num_params(TAOS_STMT *stmt, int *nums);
+int        taos_stmt_get_param(TAOS_STMT *stmt, int idx, int *type, int *bytes);
 int        taos_stmt_bind_param(TAOS_STMT *stmt, TAOS_BIND *bind);
 int        taos_stmt_add_batch(TAOS_STMT *stmt);
 int        taos_stmt_execute(TAOS_STMT *stmt);
--- a/src/inc/taosdef.h
+++ b/src/inc/taosdef.h
@ -194,9 +194,9 @@ static FORCE_INLINE bool isNull(const char *val, int32_t type) {
    case TSDB_DATA_TYPE_DOUBLE:
      return *(uint64_t *)val == TSDB_DATA_DOUBLE_NULL;
    case TSDB_DATA_TYPE_NCHAR:
-      return *(uint32_t*) varDataVal(val) == TSDB_DATA_NCHAR_NULL;
+      return varDataLen(val) == sizeof(int32_t) && *(uint32_t*) varDataVal(val) == TSDB_DATA_NCHAR_NULL;
    case TSDB_DATA_TYPE_BINARY:
-      return *(uint8_t *) varDataVal(val) == TSDB_DATA_BINARY_NULL;
+      return varDataLen(val) == sizeof(int8_t) && *(uint8_t *) varDataVal(val) == TSDB_DATA_BINARY_NULL;
    default:
      return false;
  };
@ -253,8 +253,10 @@ void tsDataSwap(void *pLeft, void *pRight, int32_t type, int32_t size, void* buf
 #define TSDB_COL_NAME_LEN         65
 #define TSDB_MAX_SAVED_SQL_LEN    TSDB_MAX_COLUMNS * 64
 #define TSDB_MAX_SQL_LEN          TSDB_PAYLOAD_SIZE
-#define TSDB_MAX_SQL_SHOW_LEN     256
-#define TSDB_MAX_ALLOWED_SQL_LEN  (1*1024*1024U)          // sql length should be less than 8mb
+#define TSDB_MAX_SQL_SHOW_LEN     512
+#define TSDB_MAX_ALLOWED_SQL_LEN  (8*1024*1024U)          // sql length should be less than 8mb
+
+#define TSDB_APPNAME_LEN          TSDB_UNI_LEN

 #define TSDB_MAX_BYTES_PER_ROW    16384
 #define TSDB_MAX_TAGS_LEN         16384
@ -282,7 +284,7 @@ void tsDataSwap(void *pLeft, void *pRight, int32_t type, int32_t size, void* buf
 #define TSDB_SHELL_VNODE_BITS     24
 #define TSDB_SHELL_SID_MASK       0xFF
 #define TSDB_HTTP_TOKEN_LEN       20
-#define TSDB_SHOW_SQL_LEN         64
+#define TSDB_SHOW_SQL_LEN         512
 #define TSDB_SLOW_QUERY_SQL_LEN   512

 #define TSDB_MQTT_HOSTNAME_LEN    64
--- a/src/inc/taoserror.h
+++ b/src/inc/taoserror.h
@ -139,6 +139,8 @@ TAOS_DEFINE_ERROR(TSDB_CODE_MND_VGROUP_ALREADY_IN_DNODE,  0, 0x0339, "Vgroup alr
 TAOS_DEFINE_ERROR(TSDB_CODE_MND_DNODE_NOT_FREE,           0, 0x033A, "Dnode not avaliable")
 TAOS_DEFINE_ERROR(TSDB_CODE_MND_INVALID_CLUSTER_ID,       0, 0x033B, "Cluster id not match")
 TAOS_DEFINE_ERROR(TSDB_CODE_MND_NOT_READY,                0, 0x033C, "Cluster not ready")
+TAOS_DEFINE_ERROR(TSDB_CODE_MND_DNODE_ID_NOT_CONFIGURED,  0, 0x033D, "Dnode Id not configured")
+TAOS_DEFINE_ERROR(TSDB_CODE_MND_DNODE_EP_NOT_CONFIGURED,  0, 0x033E, "Dnode Ep not configured")

 TAOS_DEFINE_ERROR(TSDB_CODE_MND_ACCT_ALREADY_EXIST,       0, 0x0340, "Account already exists")
 TAOS_DEFINE_ERROR(TSDB_CODE_MND_INVALID_ACCT,             0, 0x0341, "Invalid account")
@ -191,6 +193,7 @@ TAOS_DEFINE_ERROR(TSDB_CODE_VND_NO_DISK_PERMISSIONS,      0, 0x0506, "No write p
 TAOS_DEFINE_ERROR(TSDB_CODE_VND_NO_SUCH_FILE_OR_DIR,      0, 0x0507, "Missing data file")
 TAOS_DEFINE_ERROR(TSDB_CODE_VND_OUT_OF_MEMORY,            0, 0x0508, "Out of memory")
 TAOS_DEFINE_ERROR(TSDB_CODE_VND_APP_ERROR,                0, 0x0509, "Unexpected generic error in vnode")
+TAOS_DEFINE_ERROR(TSDB_CODE_VND_INVALID_VRESION_FILE,     0, 0x050A, "Invalid version file")
 TAOS_DEFINE_ERROR(TSDB_CODE_VND_NOT_SYNCED,               0, 0x0511, "Database suspended")
 TAOS_DEFINE_ERROR(TSDB_CODE_VND_NO_WRITE_AUTH,            0, 0x0512, "Write operation denied")

@ -245,6 +248,7 @@ TAOS_DEFINE_ERROR(TSDB_CODE_GRANT_CPU_LIMITED,            0, 0x080B, "CPU cores
 // sync
 TAOS_DEFINE_ERROR(TSDB_CODE_SYN_INVALID_CONFIG,           0, 0x0900, "Invalid Sync Configuration")
 TAOS_DEFINE_ERROR(TSDB_CODE_SYN_NOT_ENABLED,              0, 0x0901, "Sync module not enabled")
+TAOS_DEFINE_ERROR(TSDB_CODE_SYN_INVALID_VERSION,          0, 0x0902, "Invalid Sync version")

 // wal
 TAOS_DEFINE_ERROR(TSDB_CODE_WAL_APP_ERROR,                0, 0x1000, "Unexpected generic error in wal")
@ -350,6 +354,23 @@ TAOS_DEFINE_ERROR(TSDB_CODE_HTTP_OP_TAG_VALUE_TOO_LONG,   0, 0x11A4, "tag value
 TAOS_DEFINE_ERROR(TSDB_CODE_HTTP_OP_VALUE_NULL,           0, 0x11A5, "value not find")
 TAOS_DEFINE_ERROR(TSDB_CODE_HTTP_OP_VALUE_TYPE,           0, 0x11A6, "value type should be boolean, number or string")

+
+TAOS_DEFINE_ERROR(TSDB_CODE_ODBC_OOM,                     0, 0x2101, "out of memory")
+TAOS_DEFINE_ERROR(TSDB_CODE_ODBC_CONV_UNDEF,              0, 0x2102, "convertion undefined")
+TAOS_DEFINE_ERROR(TSDB_CODE_ODBC_CONV_TRUNC,              0, 0x2103, "convertion truncated")
+TAOS_DEFINE_ERROR(TSDB_CODE_ODBC_CONV_NOT_SUPPORT,        0, 0x2104, "convertion not supported")
+TAOS_DEFINE_ERROR(TSDB_CODE_ODBC_OUT_OF_RANGE,            0, 0x2105, "out of range")
+TAOS_DEFINE_ERROR(TSDB_CODE_ODBC_NOT_SUPPORT,             0, 0x2106, "not supported yet")
+TAOS_DEFINE_ERROR(TSDB_CODE_ODBC_INVALID_HANDLE,          0, 0x2107, "invalid handle")
+TAOS_DEFINE_ERROR(TSDB_CODE_ODBC_NO_RESULT,               0, 0x2108, "no result set")
+TAOS_DEFINE_ERROR(TSDB_CODE_ODBC_NO_FIELDS,               0, 0x2109, "no fields returned")
+TAOS_DEFINE_ERROR(TSDB_CODE_ODBC_INVALID_CURSOR,          0, 0x2110, "invalid cursor")
+TAOS_DEFINE_ERROR(TSDB_CODE_ODBC_STATEMENT_NOT_READY,     0, 0x2111, "statement not ready")
+TAOS_DEFINE_ERROR(TSDB_CODE_ODBC_CONNECTION_BUSY,         0, 0x2112, "connection still busy")
+TAOS_DEFINE_ERROR(TSDB_CODE_ODBC_BAD_CONNSTR,             0, 0x2113, "bad connection string")
+TAOS_DEFINE_ERROR(TSDB_CODE_ODBC_BAD_ARG,                 0, 0x2114, "bad argument")
+
+
 #ifdef TAOS_ERROR_C
 };
 #endif
--- a/src/inc/taosmsg.h
+++ b/src/inc/taosmsg.h
@ -59,7 +59,7 @@ TAOS_DEFINE_MESSAGE_TYPE( TSDB_MSG_TYPE_MD_DROP_STABLE, "drop-stable" )
 TAOS_DEFINE_MESSAGE_TYPE( TSDB_MSG_TYPE_MD_ALTER_STREAM, "alter-stream" )
 TAOS_DEFINE_MESSAGE_TYPE( TSDB_MSG_TYPE_MD_CONFIG_DNODE, "config-dnode" )
 TAOS_DEFINE_MESSAGE_TYPE( TSDB_MSG_TYPE_MD_ALTER_VNODE, "alter-vnode" )
-TAOS_DEFINE_MESSAGE_TYPE( TSDB_MSG_TYPE_DUMMY5, "dummy5" )
+TAOS_DEFINE_MESSAGE_TYPE( TSDB_MSG_TYPE_MD_CREATE_MNODE, "create-mnode" )
 TAOS_DEFINE_MESSAGE_TYPE( TSDB_MSG_TYPE_DUMMY6, "dummy6" )
 TAOS_DEFINE_MESSAGE_TYPE( TSDB_MSG_TYPE_DUMMY7, "dummy7" )

@ -182,10 +182,16 @@ extern char *taosMsg[];

 #pragma pack(push, 1)

+// null-terminated string instead of char array to avoid too many memory consumption in case of more than 1M tableMeta
 typedef struct {
  char     fqdn[TSDB_FQDN_LEN];
  uint16_t port;
-} SEpAddr;
+} SEpAddrMsg;
+
+typedef struct {
+  char*    fqdn;
+  uint16_t port;
+} SEpAddr1;

 typedef struct {
  int32_t numOfVnodes;
@ -245,7 +251,7 @@ typedef struct {
  int8_t   tableType;
  int16_t  numOfColumns;
  int16_t  numOfTags;
-  int32_t  sid;
+  int32_t  tid;
  int32_t  sversion;
  int32_t  tversion;
  int32_t  tagDataLen;
@ -305,6 +311,8 @@ typedef struct {
  char clientVersion[TSDB_VERSION_LEN];
  char msgVersion[TSDB_VERSION_LEN];
  char db[TSDB_TABLE_FNAME_LEN];
+  char appName[TSDB_APPNAME_LEN];
+  int32_t pid;
 } SCMConnectMsg;

 typedef struct {
@ -352,7 +360,7 @@ typedef struct {
 typedef struct {
  int32_t  contLen;
  int32_t  vgId;
-  int32_t  sid;
+  int32_t  tid;
  uint64_t uid;
  char     tableId[TSDB_TABLE_FNAME_LEN];
 } SMDDropTableMsg;
@ -399,6 +407,7 @@ typedef struct SExprInfo {
  int16_t     bytes;
  int16_t     type;
  int32_t     interBytes;
+  int64_t     uid;
 } SExprInfo;

 typedef struct SColumnFilterInfo {
@ -660,16 +669,27 @@ typedef struct SCMSTableVgroupMsg {
 } SCMSTableVgroupMsg, SCMSTableVgroupRspMsg;

 typedef struct {
-  int32_t   vgId;
-  int8_t    numOfEps;
-  SEpAddr   epAddr[TSDB_MAX_REPLICA];
+  int32_t       vgId;
+  int8_t        numOfEps;
+  SEpAddr1      epAddr[TSDB_MAX_REPLICA];
 } SCMVgroupInfo;

+typedef struct {
+  int32_t    vgId;
+  int8_t     numOfEps;
+  SEpAddrMsg epAddr[TSDB_MAX_REPLICA];
+} SCMVgroupMsg;
+
 typedef struct {
  int32_t numOfVgroups;
  SCMVgroupInfo vgroups[];
 } SVgroupsInfo;

+typedef struct {
+  int32_t numOfVgroups;
+  SCMVgroupMsg vgroups[];
+} SVgroupsMsg;
+
 typedef struct STableMetaMsg {
  int32_t       contLen;
  char          tableId[TSDB_TABLE_FNAME_LEN];   // table id
@ -680,9 +700,9 @@ typedef struct STableMetaMsg {
  int16_t       numOfColumns;
  int16_t       sversion;
  int16_t       tversion;
-  int32_t       sid;
+  int32_t       tid;
  uint64_t      uid;
-  SCMVgroupInfo vgroup;
+  SCMVgroupMsg  vgroup;
  SSchema       schema[];
 } STableMetaMsg;

@ -719,10 +739,16 @@ typedef struct {
  char     ep[TSDB_EP_LEN];  // end point, hostname:port
 } SCMCreateDnodeMsg, SCMDropDnodeMsg;

+typedef struct {
+  int32_t dnodeId;
+  char    dnodeEp[TSDB_EP_LEN];  // end point, hostname:port
+  SDMMnodeInfos mnodes;
+} SMDCreateMnodeMsg;
+
 typedef struct {
  int32_t dnodeId;
  int32_t vgId;
-  int32_t sid;
+  int32_t tid;
 } SDMConfigTableMsg;

 typedef struct {
@ -740,6 +766,7 @@ typedef struct {
  uint32_t queryId;
  int64_t  useconds;
  int64_t  stime;
+  uint64_t qHandle;
 } SQueryDesc;

 typedef struct {
@ -755,8 +782,10 @@ typedef struct {

 typedef struct {
  uint32_t connId;
+  int32_t  pid;
  int32_t  numOfQueries;
  int32_t  numOfStreams;
+  char     appName[TSDB_APPNAME_LEN];
  char     pData[];
 } SCMHeartBeatMsg;

--- a/src/inc/twal.h
+++ b/src/inc/twal.h
@ -51,6 +51,7 @@ int     walWrite(twalh, SWalHead *);
 void    walFsync(twalh);
 int     walRestore(twalh, void *pVnode, FWalWrite writeFp);
 int     walGetWalFile(twalh, char *name, uint32_t *index);
+int64_t walGetVersion(twalh);

 extern int wDebugFlag;

--- a/src/inc/vnode.h
+++ b/src/inc/vnode.h
@ -41,6 +41,8 @@ typedef struct {
  SRpcMsg  rpcMsg;
 } SReadMsg;

+extern char *vnodeStatus[];
+
 int32_t vnodeCreate(SMDCreateVnodeMsg *pVnodeCfg);
 int32_t vnodeDrop(int32_t vgId);
 int32_t vnodeOpen(int32_t vgId, char *rootDir);
@ -54,6 +56,7 @@ void    vnodeRelease(void *pVnode);        // dec refCount
 void*   vnodeGetWal(void *pVnode);

 int32_t vnodeProcessWrite(void *pVnode, int qtype, void *pHead, void *item);
+int32_t vnodeCheckWrite(void *pVnode);
 int32_t vnodeGetVnodeList(int32_t vnodeList[], int32_t *numOfVnodes);
 void    vnodeBuildStatusMsg(void *param);
 void    vnodeConfirmForward(void *param, uint64_t version, int32_t code);
@ -63,6 +66,7 @@ int32_t vnodeInitResources();
 void    vnodeCleanupResources();

 int32_t vnodeProcessRead(void *pVnode, SReadMsg *pReadMsg);
+int32_t vnodeCheckRead(void *pVnode);

 #ifdef __cplusplus
 }
--- a/src/kit/shell/inc/shell.h
+++ b/src/kit/shell/inc/shell.h
@ -20,6 +20,7 @@
 #include "taos.h"
 #include "taosdef.h"
 #include "stdbool.h"
+#include "tsclient.h"

 #define MAX_USERNAME_SIZE      64
 #define MAX_DBNAME_SIZE        64
@ -59,7 +60,7 @@ typedef struct SShellArguments {
 extern void shellParseArgument(int argc, char* argv[], SShellArguments* arguments);
 extern TAOS* shellInit(SShellArguments* args);
 extern void* shellLoopQuery(void* arg);
-extern void taos_error(TAOS* con);
+extern void taos_error(TAOS_RES* tres);
 extern int regex_match(const char* s, const char* reg, int cflags);
 void shellReadCommand(TAOS* con, char command[]);
 int32_t shellRunCommand(TAOS* con, char* command);
@ -71,7 +72,7 @@ void source_dir(TAOS* con, SShellArguments* args);
 void get_history_path(char* history);
 void cleanup_handler(void* arg);
 void exitShell();
-int shellDumpResult(TAOS* con, char* fname, int* error_no, bool printMode);
+int shellDumpResult(TAOS_RES* con, char* fname, int* error_no, bool printMode);
 void shellGetGrantInfo(void *con);
 int isCommentLine(char *line);

--- a/src/kit/shell/src/shellEngine.c
+++ b/src/kit/shell/src/shellEngine.c
@ -294,9 +294,7 @@ void shellRunCommandOnServer(TAOS *con, char command[]) {

  st = taosGetTimestampUs();

-  TAOS_RES* pSql = taos_query(con, command);
-  atomic_store_ptr(&result, pSql);  // set the global TAOS_RES pointer
-
+  TAOS_RES* pSql = taos_query_h(con, command, &result);
  if (taos_errno(pSql)) {
    taos_error(pSql);
    return;
@ -495,7 +493,7 @@ static int dumpResultToFile(const char* fname, TAOS_RES* tres) {
      if (i > 0) {
        fputc(',', fp);
      }
-      dumpFieldToFile(fp, row[i], fields +i, length[i], precision);
+      dumpFieldToFile(fp, (const char*)row[i], fields +i, length[i], precision);
    }
    fputc('\n', fp);

@ -621,7 +619,7 @@ static int verticalPrintResult(TAOS_RES* tres) {
      int padding = (int)(maxColNameLen - strlen(field->name));
      printf("%*.s%s: ", padding, " ", field->name);

-      printField(row[i], field, 0, length[i], precision);
+      printField((const char*)row[i], field, 0, length[i], precision);
      putchar('\n');
    }

@ -722,7 +720,7 @@ static int horizontalPrintResult(TAOS_RES* tres) {
    int32_t* length = taos_fetch_lengths(tres);
    for (int i = 0; i < num_fields; i++) {
      putchar(' ');
-      printField(row[i], fields + i, width[i], length[i], precision);
+      printField((const char*)row[i], fields + i, width[i], length[i], precision);
      putchar(' ');
      putchar('|');
    }
--- a/src/kit/shell/src/shellImport.c
+++ b/src/kit/shell/src/shellImport.c
@ -204,7 +204,7 @@ static void shellSourceFile(TAOS *con, char *fptr) {
    int32_t code = taos_errno(pSql);
    
    if (code != 0) {
-      fprintf(stderr, "DB error: %s: %s (%d)\n", taos_errstr(con), fname, lineNo);
+      fprintf(stderr, "DB error: %s: %s (%d)\n", taos_errstr(pSql), fname, lineNo);
    }
    
    /* free local resouce: allocated memory/metric-meta refcnt */
@ -243,7 +243,7 @@ static void shellRunImportThreads(SShellArguments* args)
    pThread->totalThreads = args->threadNum;
    pThread->taos = taos_connect(args->host, args->user, args->password, args->database, tsDnodeShellPort);
    if (pThread->taos == NULL) {
-      fprintf(stderr, "ERROR: thread:%d failed connect to TDengine, error:%s\n", pThread->threadIndex, taos_errstr(pThread->taos));
+      fprintf(stderr, "ERROR: thread:%d failed connect to TDengine, error:%s\n", pThread->threadIndex, "null taos"/*taos_errstr(pThread->taos)*/);
      exit(0);
    }

--- a/src/kit/shell/src/shellWindows.c
+++ b/src/kit/shell/src/shellWindows.c
@ -90,11 +90,12 @@ void shellParseArgument(int argc, char *argv[], SShellArguments *arguments) {
      }
    } else if (strcmp(argv[i], "-c") == 0) {
      if (i < argc - 1) {   
-        if (strlen(argv[++i]) >= TSDB_FILENAME_LEN) {
-          fprintf(stderr, "config file path: %s overflow max len %d\n", argv[i], TSDB_FILENAME_LEN - 1);
+        char *tmp = argv[++i];
+        if (strlen(tmp) >= TSDB_FILENAME_LEN) {
+          fprintf(stderr, "config file path: %s overflow max len %d\n", tmp, TSDB_FILENAME_LEN - 1);
          exit(EXIT_FAILURE);
        }
-        strcpy(configDir, argv[++i]);
+        strcpy(configDir, tmp);
      } else {
        fprintf(stderr, "Option -c requires an argument\n");
        exit(EXIT_FAILURE);
--- a/src/mnode/inc/mnodeDef.h
+++ b/src/mnode/inc/mnodeDef.h
@ -115,7 +115,7 @@ typedef struct {
  uint64_t   suid;
  int64_t    createdTime;
  int32_t    numOfColumns; //used by normal table
-  int32_t    sid;
+  int32_t    tid;
  int32_t    vgId;
  int32_t    sqlLen;
  int8_t     updateEnd[4];
--- a/src/mnode/inc/mnodeMnode.h
+++ b/src/mnode/inc/mnodeMnode.h
@ -31,7 +31,7 @@ typedef enum {
 int32_t mnodeInitMnodes();
 void    mnodeCleanupMnodes();

-int32_t mnodeAddMnode(int32_t dnodeId);
+void    mnodeCreateMnode(int32_t dnodeId, char *dnodeEp, bool needConfirm);
 int32_t mnodeDropMnode(int32_t dnodeId);
 void    mnodeDropMnodeLocal(int32_t dnodeId);

--- a/src/mnode/inc/mnodeProfile.h
+++ b/src/mnode/inc/mnodeProfile.h
@ -23,6 +23,8 @@ extern "C" {

 typedef struct {
  char     user[TSDB_USER_LEN];
+  char     appName[TSDB_APPNAME_LEN];  // app name that invokes taosc
+  uint32_t pid;                        // pid of app that invokes taosc
  int8_t   killed;
  uint16_t port;
  uint32_t ip;
@ -40,7 +42,7 @@ typedef struct {
 int32_t mnodeInitProfile();
 void    mnodeCleanupProfile();

-SConnObj *mnodeCreateConn(char *user, uint32_t ip, uint16_t port);
+SConnObj *mnodeCreateConn(char *user, uint32_t ip, uint16_t port, int32_t pid, const char* app);
 SConnObj *mnodeAccquireConn(int32_t connId, char *user, uint32_t ip, uint16_t port);
 void      mnodeReleaseConn(SConnObj *pConn);
 int32_t   mnodeSaveQueryStreamList(SConnObj *pConn, SCMHeartBeatMsg *pHBMsg);
--- a/src/mnode/src/mnodeCluster.c
+++ b/src/mnode/src/mnodeCluster.c
@ -225,6 +225,7 @@ static int32_t mnodeRetrieveClusters(SShowObj *pShow, char *data, int32_t rows,
    numOfRows++;
  }

+  mnodeVacuumResult(data, pShow->numOfColumns, numOfRows, rows, pShow);
  pShow->numOfReads += numOfRows;
  return numOfRows;
 }
--- a/src/mnode/src/mnodeDb.c
+++ b/src/mnode/src/mnodeDb.c
@ -648,8 +648,12 @@ static int32_t mnodeRetrieveDbs(SShowObj *pShow, char *data, int32_t rows, void

  while (numOfRows < rows) {
    pShow->pIter = mnodeGetNextDb(pShow->pIter, &pDb);
+
    if (pDb == NULL) break;
-    if (pDb->pAcct != pUser->pAcct) continue;
+    if (pDb->pAcct != pUser->pAcct) {
+      mnodeDecDbRef(pDb);
+      continue;
+    }

    cols = 0;

@ -760,7 +764,7 @@ static int32_t mnodeRetrieveDbs(SShowObj *pShow, char *data, int32_t rows, void
  }

  pShow->numOfReads += numOfRows;
-  mnodeVacuumResult(data, cols, numOfRows, rows, pShow);
+  mnodeVacuumResult(data, pShow->numOfColumns, numOfRows, rows, pShow);

  mnodeDecUserRef(pUser);
  return numOfRows;
--- a/src/mnode/src/mnodeDnode.c
+++ b/src/mnode/src/mnodeDnode.c
@ -147,7 +147,7 @@ static int32_t mnodeDnodeActionRestored() {
    mnodeCreateDnode(tsLocalEp, NULL);
    SDnodeObj *pDnode = mnodeGetDnodeByEp(tsLocalEp);
    if (pDnode != NULL) {
-      mnodeAddMnode(pDnode->dnodeId);
+      mnodeCreateMnode(pDnode->dnodeId, pDnode->dnodeEp, false);
      mnodeDecDnodeRef(pDnode);
    }
  }
@ -471,7 +471,8 @@ static int32_t mnodeProcessDnodeStatusMsg(SMnodeMsg *pMsg) {
             mnodeGetClusterId());
      return TSDB_CODE_MND_INVALID_CLUSTER_ID;
    } else {
-      mTrace("dnode:%d, status received, access times %d", pDnode->dnodeId, pDnode->lastAccess);
+      mTrace("dnode:%d, status received, access times %d openVnodes:%d:%d", pDnode->dnodeId, pDnode->lastAccess,
+             htons(pStatus->openVnodes), pDnode->openVnodes);
    }
  }

@ -790,6 +791,7 @@ static int32_t mnodeRetrieveDnodes(SShowObj *pShow, char *data, int32_t rows, vo
    mnodeDecDnodeRef(pDnode);
  }

+  mnodeVacuumResult(data, pShow->numOfColumns, numOfRows, rows, pShow);
  pShow->numOfReads += numOfRows;
  return numOfRows;
 }
@ -857,6 +859,7 @@ int32_t mnodeRetrieveModules(SShowObj *pShow, char *data, int32_t rows, void *pC

  char* pWrite;
  char* moduleName[5] = { "MNODE", "HTTP", "MONITOR", "MQTT", "UNKNOWN" };
+  int32_t cols;

  while (numOfRows < rows) {
    SDnodeObj *pDnode = NULL;
@ -864,7 +867,7 @@ int32_t mnodeRetrieveModules(SShowObj *pShow, char *data, int32_t rows, void *pC
    if (pDnode == NULL) break;

    for (int32_t moduleType = 0; moduleType < TSDB_MOD_MAX; ++moduleType) {
-      int32_t cols = 0;
+      cols = 0;

      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
      *(int16_t *)pWrite = pDnode->dnodeId;
@ -891,6 +894,7 @@ int32_t mnodeRetrieveModules(SShowObj *pShow, char *data, int32_t rows, void *pC
    mnodeDecDnodeRef(pDnode);
  }

+  mnodeVacuumResult(data, pShow->numOfColumns, numOfRows, rows, pShow);
  pShow->numOfReads += numOfRows;
  return numOfRows;
 }
@ -990,6 +994,7 @@ static int32_t mnodeRetrieveConfigs(SShowObj *pShow, char *data, int32_t rows, v
    }
  }

+  mnodeVacuumResult(data, pShow->numOfColumns, numOfRows, rows, pShow);
  pShow->numOfReads += numOfRows;
  return numOfRows;
 }
@ -1082,6 +1087,7 @@ static int32_t mnodeRetrieveVnodes(SShowObj *pShow, char *data, int32_t rows, vo
    numOfRows = 0;
  }

+  mnodeVacuumResult(data, pShow->numOfColumns, numOfRows, rows, pShow);
  pShow->numOfReads += numOfRows;
  return numOfRows;
 }
--- a/src/mnode/src/mnodeMain.c
+++ b/src/mnode/src/mnodeMain.c
@ -109,7 +109,7 @@ int32_t mnodeStartSystem() {

  mInfo("mnode is initialized successfully");

-  sdbUpdateSync();
+  sdbUpdateSync(NULL);

  return 0;
 }
--- a/src/mnode/src/mnodeMnode.c
+++ b/src/mnode/src/mnodeMnode.c
@ -23,6 +23,8 @@
 #include "tutil.h"
 #include "tsocket.h"
 #include "tdataformat.h"
+#include "dnode.h"
+#include "mnode.h"
 #include "mnodeDef.h"
 #include "mnodeInt.h"
 #include "mnodeMnode.h"
@ -30,6 +32,7 @@
 #include "mnodeSdb.h"
 #include "mnodeShow.h"
 #include "mnodeUser.h"
+#include "mnodeVgroup.h"

 static void *        tsMnodeSdb = NULL;
 static int32_t       tsMnodeUpdateSize = 0;
@ -266,25 +269,87 @@ void mnodeGetMnodeInfos(void *mnodeInfos) {
  mnodeMnodeUnLock();
 }

-int32_t mnodeAddMnode(int32_t dnodeId) {
+static int32_t mnodeSendCreateMnodeMsg(int32_t dnodeId, char *dnodeEp) {
+  mDebug("dnode:%d, send create mnode msg to dnode %s", dnodeId, dnodeEp);
+
+  SMDCreateMnodeMsg *pCreate = rpcMallocCont(sizeof(SMDCreateMnodeMsg));
+  if (pCreate == NULL) {
+    return TSDB_CODE_MND_OUT_OF_MEMORY;
+  } else {
+    pCreate->dnodeId = htonl(dnodeId);
+    tstrncpy(pCreate->dnodeEp, dnodeEp, sizeof(pCreate->dnodeEp));
+    pCreate->mnodes = tsMnodeInfos;
+    bool found = false;
+    for (int i = 0; i < pCreate->mnodes.nodeNum; ++i) {
+      if (pCreate->mnodes.nodeInfos[i].nodeId == htonl(dnodeId)) {
+        found = true;
+      }
+    }
+    if (!found) {
+      pCreate->mnodes.nodeInfos[pCreate->mnodes.nodeNum].nodeId = htonl(dnodeId);
+      tstrncpy(pCreate->mnodes.nodeInfos[pCreate->mnodes.nodeNum].nodeEp, dnodeEp, sizeof(pCreate->dnodeEp));
+      pCreate->mnodes.nodeNum++;
+    }
+  }
+
+  SRpcMsg rpcMsg = {0};
+  rpcMsg.pCont = pCreate;
+  rpcMsg.contLen = sizeof(SMDCreateMnodeMsg);
+  rpcMsg.msgType = TSDB_MSG_TYPE_MD_CREATE_MNODE;
+
+  SRpcMsg   rpcRsp = {0};
+  SRpcEpSet epSet = mnodeGetEpSetFromIp(pCreate->dnodeEp);
+  dnodeSendMsgToDnodeRecv(&rpcMsg, &rpcRsp, &epSet);
+
+  if (rpcRsp.code != TSDB_CODE_SUCCESS) {
+    mError("dnode:%d, failed to send create mnode msg, ep:%s reason:%s", dnodeId, dnodeEp, tstrerror(rpcRsp.code));
+  } else {
+    mDebug("dnode:%d, create mnode msg is disposed, mnode is created in dnode", dnodeId);
+  }
+
+  rpcFreeCont(rpcRsp.pCont);
+  return rpcRsp.code;
+}
+
+static int32_t mnodeCreateMnodeCb(SMnodeMsg *pMsg, int32_t code) {
+  if (code != TSDB_CODE_SUCCESS) {
+    mError("failed to create mnode, reason:%s", tstrerror(code));
+  } else {
+    mDebug("mnode is created successfully");
+    mnodeUpdateMnodeEpSet();
+    sdbUpdateAsync();
+  }
+
+  return code;
+}
+
+void mnodeCreateMnode(int32_t dnodeId, char *dnodeEp, bool needConfirm) {
  SMnodeObj *pMnode = calloc(1, sizeof(SMnodeObj));
  pMnode->mnodeId = dnodeId;
  pMnode->createdTime = taosGetTimestampMs();

  SSdbOper oper = {
-    .type = SDB_OPER_GLOBAL,
+    .type  = SDB_OPER_GLOBAL,
    .table = tsMnodeSdb,
-    .pObj = pMnode,
+    .pObj  = pMnode,
+    .writeCb = mnodeCreateMnodeCb
  };

-  int32_t code = sdbInsertRow(&oper);
-  if (code != TSDB_CODE_SUCCESS && code != TSDB_CODE_MND_ACTION_IN_PROGRESS) {
-    taosTFree(pMnode);
+  int32_t code = TSDB_CODE_SUCCESS;
+  if (needConfirm) {
+    code = mnodeSendCreateMnodeMsg(dnodeId, dnodeEp);
  }

-  mnodeUpdateMnodeEpSet();
+  if (code != TSDB_CODE_SUCCESS) {
+    taosTFree(pMnode);
+    return;
+  }

-  return code;
+  code = sdbInsertRow(&oper);
+  if (code != TSDB_CODE_SUCCESS && code != TSDB_CODE_MND_ACTION_IN_PROGRESS) {
+    mError("dnode:%d, failed to create mnode, ep:%s reason:%s", dnodeId, dnodeEp, tstrerror(code));
+    taosTFree(pMnode);
+  }
 }

 void mnodeDropMnodeLocal(int32_t dnodeId) {
@ -296,6 +361,7 @@ void mnodeDropMnodeLocal(int32_t dnodeId) {
  }

  mnodeUpdateMnodeEpSet();
+  sdbUpdateAsync();
 }

 int32_t mnodeDropMnode(int32_t dnodeId) {
@ -315,6 +381,7 @@ int32_t mnodeDropMnode(int32_t dnodeId) {
  sdbDecRef(tsMnodeSdb, pMnode);

  mnodeUpdateMnodeEpSet();
+  sdbUpdateAsync();

  return code;
 }
@ -414,6 +481,7 @@ static int32_t mnodeRetrieveMnodes(SShowObj *pShow, char *data, int32_t rows, vo
    mnodeDecMnodeRef(pMnode);
  }

+  mnodeVacuumResult(data, pShow->numOfColumns, numOfRows, rows, pShow);
  pShow->numOfReads += numOfRows;

  return numOfRows;
--- a/src/mnode/src/mnodePeer.c
+++ b/src/mnode/src/mnodePeer.c
@ -58,10 +58,15 @@ int32_t mnodeProcessPeerReq(SMnodeMsg *pMsg) {
    rpcRsp->rsp = epSet;
    rpcRsp->len = sizeof(SRpcEpSet);

-    mDebug("%p, msg:%s in mpeer queue, will be redireced, numOfEps:%d inUse:%d", pMsg->rpcMsg.ahandle,
+    mDebug("%p, msg:%s in mpeer queue will be redirected, numOfEps:%d inUse:%d", pMsg->rpcMsg.ahandle,
           taosMsg[pMsg->rpcMsg.msgType], epSet->numOfEps, epSet->inUse);
    for (int32_t i = 0; i < epSet->numOfEps; ++i) {
-      mDebug("mnode index:%d ep:%s:%d", i, epSet->fqdn[i], htons(epSet->port[i]));
+      if (strcmp(epSet->fqdn[i], tsLocalFqdn) == 0 && htons(epSet->port[i]) == tsServerPort + TSDB_PORT_DNODEDNODE) {
+        epSet->inUse = (i + 1) % epSet->numOfEps;
+        mDebug("mnode index:%d ep:%s:%u, set inUse to %d", i, epSet->fqdn[i], htons(epSet->port[i]), epSet->inUse);
+      } else {
+        mDebug("mnode index:%d ep:%s:%u", i, epSet->fqdn[i], htons(epSet->port[i]));
+      }
    }

    return TSDB_CODE_RPC_REDIRECT;
--- a/src/mnode/src/mnodeProfile.c
+++ b/src/mnode/src/mnodeProfile.c
@ -24,15 +24,9 @@
 #include "mnode.h"
 #include "mnodeDef.h"
 #include "mnodeInt.h"
-#include "mnodeAcct.h"
-#include "mnodeDnode.h"
-#include "mnodeDb.h"
-#include "mnodeMnode.h"
 #include "mnodeProfile.h"
 #include "mnodeShow.h"
-#include "mnodeTable.h"
 #include "mnodeUser.h"
-#include "mnodeVgroup.h"
 #include "mnodeWrite.h"

 #define CONN_KEEP_TIME  (tsShellActivityTimer * 3)
@ -78,7 +72,7 @@ void mnodeCleanupProfile() {
  }
 }

-SConnObj *mnodeCreateConn(char *user, uint32_t ip, uint16_t port) {
+SConnObj *mnodeCreateConn(char *user, uint32_t ip, uint16_t port, int32_t pid, const char* app) {
 #if 0
  int32_t connSize = taosHashGetSize(tsMnodeConnCache->pHashTable);
  if (connSize > tsMaxShellConns) {
@ -96,10 +90,13 @@ SConnObj *mnodeCreateConn(char *user, uint32_t ip, uint16_t port) {
    .ip     = ip,
    .port   = port,
    .connId = connId,
-    .stime  = taosGetTimestampMs()
+    .stime  = taosGetTimestampMs(),
+    .pid    = pid,
  };

-  tstrncpy(connObj.user, user, sizeof(connObj.user));
+  tstrncpy(connObj.user, user, tListLen(connObj.user));
+  tstrncpy(connObj.appName, app, tListLen(connObj.appName));
+
  connObj.lastAccess = connObj.stime;

  SConnObj *pConn = taosCachePut(tsMnodeConnCache, &connId, sizeof(int32_t), &connObj, sizeof(connObj), CONN_KEEP_TIME * 1000);
@ -114,7 +111,6 @@ 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 = 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);
@ -129,7 +125,7 @@ SConnObj *mnodeAccquireConn(int32_t connId, char *user, uint32_t ip, uint16_t po
  }

  // mDebug("connId:%d, is incoming, user:%s ip:%s:%u", connId, pConn->user, taosIpStr(pConn->ip), pConn->port);
-  pConn->lastAccess = expireTime;
+  pConn->lastAccess = CONN_KEEP_TIME * 1000 + (uint64_t)taosGetTimestampMs();
  return pConn;
 }

@ -183,6 +179,20 @@ static int32_t mnodeGetConnsMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pC
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

+  // app name
+  pShow->bytes[cols] = TSDB_APPNAME_LEN + VARSTR_HEADER_SIZE;
+  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
+  strcpy(pSchema[cols].name, "app_name");
+  pSchema[cols].bytes = htons(pShow->bytes[cols]);
+  cols++;
+
+  // app pid
+  pShow->bytes[cols] = 4;
+  pSchema[cols].type = TSDB_DATA_TYPE_INT;
+  strcpy(pSchema[cols].name, "pid");
+  pSchema[cols].bytes = htons(pShow->bytes[cols]);
+  cols++;
+
  pShow->bytes[cols] = TSDB_IPv4ADDR_LEN + 6 + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
  strcpy(pSchema[cols].name, "ip:port");
@ -191,13 +201,13 @@ static int32_t mnodeGetConnsMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pC

  pShow->bytes[cols] = 8;
  pSchema[cols].type = TSDB_DATA_TYPE_TIMESTAMP;
-  strcpy(pSchema[cols].name, "login time");
+  strcpy(pSchema[cols].name, "login_time");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

  pShow->bytes[cols] = 8;
  pSchema[cols].type = TSDB_DATA_TYPE_TIMESTAMP;
-  strcpy(pSchema[cols].name, "last access");
+  strcpy(pSchema[cols].name, "last_access");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

@ -236,6 +246,16 @@ static int32_t mnodeRetrieveConns(SShowObj *pShow, char *data, int32_t rows, voi
    STR_WITH_MAXSIZE_TO_VARSTR(pWrite, pConnObj->user, pShow->bytes[cols]);
    cols++;

+    // app name
+    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
+    STR_WITH_MAXSIZE_TO_VARSTR(pWrite, pConnObj->appName, pShow->bytes[cols]);
+    cols++;
+
+    // app pid
+    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
+    *(int32_t*)pWrite = pConnObj->pid;
+    cols++;
+
    pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
    snprintf(ipStr, sizeof(ipStr), "%s:%u", taosIpStr(pConnObj->ip), pConnObj->port);
    STR_WITH_MAXSIZE_TO_VARSTR(pWrite, ipStr, pShow->bytes[cols]);
@ -254,8 +274,7 @@ static int32_t mnodeRetrieveConns(SShowObj *pShow, char *data, int32_t rows, voi
  }

  pShow->numOfReads += numOfRows;
-  const int32_t NUM_OF_COLUMNS = 5;
-  mnodeVacuumResult(data, NUM_OF_COLUMNS, numOfRows, rows, pShow);
+  mnodeVacuumResult(data, pShow->numOfColumns, numOfRows, rows, pShow);
  
  return numOfRows;
 }
@ -299,7 +318,7 @@ static int32_t mnodeGetQueryMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pC

  pShow->bytes[cols] = QUERY_ID_SIZE + VARSTR_HEADER_SIZE;
  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
-  strcpy(pSchema[cols].name, "queryId");
+  strcpy(pSchema[cols].name, "query_id");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

@ -315,9 +334,15 @@ static int32_t mnodeGetQueryMeta(STableMetaMsg *pMeta, SShowObj *pShow, void *pC
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

+  pShow->bytes[cols] = 24;
+  pSchema[cols].type = TSDB_DATA_TYPE_BINARY;
+  strcpy(pSchema[cols].name, "qhandle");
+  pSchema[cols].bytes = htons(pShow->bytes[cols]);
+  cols++;
+
  pShow->bytes[cols] = 8;
  pSchema[cols].type = TSDB_DATA_TYPE_TIMESTAMP;
-  strcpy(pSchema[cols].name, "created time");
+  strcpy(pSchema[cols].name, "created_time");
  pSchema[cols].bytes = htons(pShow->bytes[cols]);
  cols++;

@ -352,7 +377,7 @@ static int32_t mnodeRetrieveQueries(SShowObj *pShow, char *data, int32_t rows, v
  SConnObj *pConnObj = NULL;
  int32_t   cols = 0;
  char *    pWrite;
-  char      ipStr[TSDB_IPv4ADDR_LEN + 6];
+  char      str[TSDB_IPv4ADDR_LEN + 6] = {0};

  while (numOfRows < rows) {
    pShow->pIter = mnodeGetNextConn(pShow->pIter, &pConnObj);
@ -362,9 +387,9 @@ static int32_t mnodeRetrieveQueries(SShowObj *pShow, char *data, int32_t rows, v
      SQueryDesc *pDesc = pConnObj->pQueries + i;
      cols = 0;

-      snprintf(ipStr, QUERY_ID_SIZE + 1, "%u:%u", pConnObj->connId, htonl(pDesc->queryId));
+      snprintf(str, QUERY_ID_SIZE + 1, "%u:%u", pConnObj->connId, htonl(pDesc->queryId));
      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
-      STR_WITH_MAXSIZE_TO_VARSTR(pWrite, ipStr, pShow->bytes[cols]);
+      STR_WITH_MAXSIZE_TO_VARSTR(pWrite, str, pShow->bytes[cols]);
      cols++;

      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
@ -372,8 +397,15 @@ static int32_t mnodeRetrieveQueries(SShowObj *pShow, char *data, int32_t rows, v
      cols++;

      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
-      snprintf(ipStr, sizeof(ipStr), "%s:%u", taosIpStr(pConnObj->ip), pConnObj->port);
-      STR_WITH_MAXSIZE_TO_VARSTR(pWrite, ipStr, pShow->bytes[cols]);
+      snprintf(str, tListLen(str), "%s:%u", taosIpStr(pConnObj->ip), pConnObj->port);
+      STR_WITH_MAXSIZE_TO_VARSTR(pWrite, str, pShow->bytes[cols]);
+      cols++;
+
+      char handleBuf[24] = {0};
+      snprintf(handleBuf, tListLen(handleBuf), "%p", (void*)htobe64(pDesc->qHandle));
+      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
+
+      STR_WITH_MAXSIZE_TO_VARSTR(pWrite, handleBuf, pShow->bytes[cols]);
      cols++;

      pWrite = data + pShow->offset[cols] * rows + pShow->bytes[cols] * numOfRows;
@ -393,8 +425,7 @@ static int32_t mnodeRetrieveQueries(SShowObj *pShow, char *data, int32_t rows, v
  }

  pShow->numOfReads += numOfRows;
-  const int32_t NUM_OF_COLUMNS = 6;
-  mnodeVacuumResult(data, NUM_OF_COLUMNS, numOfRows, rows, pShow);
+  mnodeVacuumResult(data, pShow->numOfColumns, numOfRows, rows, pShow);
  return numOfRows;
 }

@ -522,8 +553,7 @@ static int32_t mnodeRetrieveStreams(SShowObj *pShow, char *data, int32_t rows, v
  }

  pShow->numOfReads += numOfRows;
-  const int32_t NUM_OF_COLUMNS = 8;
-  mnodeVacuumResult(data, NUM_OF_COLUMNS, numOfRows, rows, pShow);
+  mnodeVacuumResult(data, pShow->numOfColumns, numOfRows, rows, pShow);
  return numOfRows;
 }

@ -595,7 +625,7 @@ static int32_t mnodeProcessKillConnectionMsg(SMnodeMsg *pMsg) {

  SCMKillConnMsg *pKill = pMsg->rpcMsg.pCont;
  int32_t connId = atoi(pKill->queryId);
-  SConnObj *      pConn = taosCacheAcquireByKey(tsMnodeConnCache, &connId, sizeof(int32_t));
+  SConnObj *pConn = taosCacheAcquireByKey(tsMnodeConnCache, &connId, sizeof(int32_t));
  if (pConn == NULL) {
    mError("connId:%s, failed to kill, conn not exist", pKill->queryId);
    return TSDB_CODE_MND_INVALID_CONN_ID;
--- a/src/mnode/src/mnodeRead.c
+++ b/src/mnode/src/mnodeRead.c
@ -51,14 +51,21 @@ int32_t mnodeProcessRead(SMnodeMsg *pMsg) {
    SMnodeRsp *rpcRsp = &pMsg->rpcRsp;
    SRpcEpSet *epSet = rpcMallocCont(sizeof(SRpcEpSet));
    mnodeGetMnodeEpSetForShell(epSet);
+
+    mDebug("%p, msg:%s in mread queue will be redirected, numOfEps:%d inUse:%d", pMsg->rpcMsg.ahandle,
+           taosMsg[pMsg->rpcMsg.msgType], epSet->numOfEps, epSet->inUse);
+    for (int32_t i = 0; i < epSet->numOfEps; ++i) {
+      if (strcmp(epSet->fqdn[i], tsLocalFqdn) == 0 && htons(epSet->port[i]) == tsServerPort) {
+        epSet->inUse = (i + 1) % epSet->numOfEps;
+        mDebug("mnode index:%d ep:%s:%u, set inUse to %d", i, epSet->fqdn[i], htons(epSet->port[i]), epSet->inUse);
+      } else {
+        mDebug("mnode index:%d ep:%s:%u", i, epSet->fqdn[i], htons(epSet->port[i]));
+      }
+    }
+
    rpcRsp->rsp = epSet;
    rpcRsp->len = sizeof(SRpcEpSet);

-    mDebug("%p, msg:%s in mread queue, will be redireced, inUse:%d", pMsg->rpcMsg.ahandle, taosMsg[pMsg->rpcMsg.msgType], epSet->inUse);
-    for (int32_t i = 0; i < epSet->numOfEps; ++i) {
-      mDebug("mnode index:%d ep:%s:%d", i, epSet->fqdn[i], htons(epSet->port[i]));
-    }
-
    return TSDB_CODE_RPC_REDIRECT;
  }

--- a/Show More
+++ b/Show More