diff --git a/documentation20/webdocs/markdowndocs/TAOS SQL-ch.md b/documentation20/webdocs/markdowndocs/TAOS SQL-ch.md
index 946eec53ad9cc14b91870708ca9d9594dcec8671..4563b5b5fcce75697e6c731622e32666df3f8bdf 100644
--- a/documentation20/webdocs/markdowndocs/TAOS SQL-ch.md	
+++ b/documentation20/webdocs/markdowndocs/TAOS SQL-ch.md	
@@ -743,7 +743,7 @@ TDengine支持针对数据的聚合查询。提供支持的聚合和选择函数
 
     应用字段：不能应用在timestamp、binary、nchar、bool类型字段。
 
-    适用于：表。
+    适用于：表。（从 2.0.15 版本开始，本函数也支持超级表）
 
     示例：
     ```mysql
@@ -1157,7 +1157,7 @@ SELECT AVG(current), MAX(current), LEASTSQUARES(current, start_val, step_val), P
 - 数据库名最大长度为32
 - 表名最大长度为192，每行数据最大长度16k个字符
 - 列名最大长度为64，最多允许1024列，最少需要2列，第一列必须是时间戳
-- 标签最多允许128个，可以0个，标签总长度不超过16k个字符
+- 标签最多允许128个，可以1个，标签总长度不超过16k个字符
 - SQL语句最大长度65480个字符，但可通过系统配置参数maxSQLLength修改，最长可配置为1M
 - 库的数目，超级表的数目、表的数目，系统不做限制，仅受系统资源限制
 
diff --git a/documentation20/webdocs/markdowndocs/architecture-ch.md b/documentation20/webdocs/markdowndocs/architecture-ch.md
index a666f755156906adb9c4d3e8c18e3e4f8679e255..773d8196f26ff414a9546b474713f46bfb0dd5ac 100644
--- a/documentation20/webdocs/markdowndocs/architecture-ch.md
+++ b/documentation20/webdocs/markdowndocs/architecture-ch.md
@@ -248,7 +248,7 @@ Master Vnode遵循下面的写入流程：
 1. Master vnode收到应用的数据插入请求，验证OK，进入下一步；
 2. 如果系统配置参数walLevel大于0，vnode将把该请求的原始数据包写入数据库日志文件WAL。如果walLevel设置为2，而且fsync设置为0，TDengine还将WAL数据立即落盘，以保证即使宕机，也能从数据库日志文件中恢复数据，避免数据的丢失；
 3. 如果有多个副本，vnode将把数据包转发给同一虚拟节点组内slave vnodes, 该转发包带有数据的版本号(version)；
-4. 写入内存，并加记录加入到skip list；
+4. 写入内存，并将记录加入到skip list；
 5. Master vnode返回确认信息给应用，表示写入成功。
 6. 如果第2，3，4步中任何一步失败，将直接返回错误给应用。
 
diff --git a/documentation20/webdocs/markdowndocs/connector-ch.md b/documentation20/webdocs/markdowndocs/connector-ch.md
index da9c2e5a119e56243e517e9de0e248184d3c3c93..bcaabe3c0a48837cc50d1d2f5f212a57c8e5c912 100644
--- a/documentation20/webdocs/markdowndocs/connector-ch.md
+++ b/documentation20/webdocs/markdowndocs/connector-ch.md
@@ -288,13 +288,6 @@ C/C++的API类似于MySQL的C API。应用程序使用时，需要包含TDengine
     * res：`taos_query_a`回调时返回的结果集
     * fp：回调函数。其参数`param`是用户可定义的传递给回调函数的参数结构体；`numOfRows`是获取到的数据的行数（不是整个查询结果集的函数）。 在回调函数中，应用可以通过调用`taos_fetch_row`前向迭代获取批量记录中每一行记录。读完一块内的所有记录后，应用需要在回调函数中继续调用`taos_fetch_rows_a`获取下一批记录进行处理，直到返回的记录数（numOfRows）为零（结果返回完成）或记录数为负值（查询出错）。
 
-- `void taos_fetch_row_a(TAOS_RES *res, void (*fp)(void *param, TAOS_RES *, TAOS_ROW row), void *param);`
-
-  异步获取一条记录。其中：
-
-    * res：`taos_query_a`回调时返回的结果集
-    * fp：回调函数。其参数`param`是应用提供的一个用于回调的参数。回调时，第三个参数`row`指向一行记录。不同于`taos_fetch_rows_a`，应用无需调用`taos_fetch_row`来获取一行数据，更加简单，但数据提取性能不及批量获取的API。
-
 TDengine的异步API均采用非阻塞调用模式。应用程序可以用多线程同时打开多张表，并可以同时对每张打开的表进行查询或者插入操作。需要指出的是，**客户端应用必须确保对同一张表的操作完全串行化**，即对同一个表的插入或查询操作未完成时（未返回时），不能够执行第二个插入或查询操作。
 
 ### 参数绑定API
diff --git a/src/kit/taosdemox/taosdemox.c b/src/kit/taosdemox/taosdemox.c
index 5c187030c521193e024062763c342cd0d928133c..2968d653313c56ffc1842969cadfcc1458fef4a4 100644
--- a/src/kit/taosdemox/taosdemox.c
+++ b/src/kit/taosdemox/taosdemox.c
@@ -1085,8 +1085,8 @@ static void printfQueryMeta() {
   printf("database name:           \033[33m%s\033[0m\n", g_queryInfo.dbName);
 
   printf("\n");
-  printf("super table query info:                   \n");  
-  printf("rate:           \033[33m%d\033[0m\n", g_queryInfo.superQueryInfo.rate);
+  printf("specified table query info:                   \n");  
+  printf("query interval: \033[33m%d\033[0m\n", g_queryInfo.superQueryInfo.rate);
   printf("concurrent:     \033[33m%d\033[0m\n", g_queryInfo.superQueryInfo.concurrent);
   printf("sqlCount:       \033[33m%d\033[0m\n", g_queryInfo.superQueryInfo.sqlCount); 
 
@@ -1102,11 +1102,11 @@ static void printfQueryMeta() {
     printf("  sql[%d]: \033[33m%s\033[0m\n", i, g_queryInfo.superQueryInfo.sql[i]);
   }
   printf("\n");
-  printf("sub table query info:                   \n");  
-  printf("rate:           \033[33m%d\033[0m\n", g_queryInfo.subQueryInfo.rate);
+  printf("super table query info:                   \n");  
+  printf("query interval: \033[33m%d\033[0m\n", g_queryInfo.subQueryInfo.rate);
   printf("threadCnt:      \033[33m%d\033[0m\n", g_queryInfo.subQueryInfo.threadCnt);
   printf("childTblCount:  \033[33m%d\033[0m\n", g_queryInfo.subQueryInfo.childTblCount);
-  printf("childTblPrefix: \033[33m%s\033[0m\n", g_queryInfo.subQueryInfo.childTblPrefix);
+  printf("stable name:    \033[33m%s\033[0m\n", g_queryInfo.subQueryInfo.sTblName);
 
   if (SUBSCRIBE_MODE == g_jsonType) {
     printf("mod:            \033[33m%d\033[0m\n", g_queryInfo.subQueryInfo.subscribeMode);
@@ -4020,23 +4020,23 @@ void *superQueryProcess(void *sarg) {
         }
         selectAndGetResult(winfo->taos, g_queryInfo.superQueryInfo.sql[i], tmpFile); 
         int64_t t2 = taosGetTimestampUs();          
-        printf("taosc select sql return, Spent %f s\n", (t2 - t1)/1000000.0);          
+        printf("=[taosc] thread[%"PRIu64"] complete one sql, Spent %f s\n", (uint64_t)pthread_self(), (t2 - t1)/1000000.0);          
       } else {
         #ifdef TD_LOWA_CURL
         int64_t t1 = taosGetTimestampUs();
         int retCode = curlProceSql(g_queryInfo.host, g_queryInfo.port, g_queryInfo.superQueryInfo.sql[i], winfo->curl_handle);
         int64_t t2 = taosGetTimestampUs();          
-        printf("http select sql return, Spent %f s \n", (t2 - t1)/1000000.0);
+        printf("=[restful] thread[%"PRIu64"] complete one sql, Spent %f s\n", (uint64_t)pthread_self(), (t2 - t1)/1000000.0);
         
         if (0 != retCode) {
-          printf("========curl return fail, threadID[%d]\n", winfo->threadID);
+          printf("====curl return fail, threadID[%d]\n", winfo->threadID);
           return NULL;
         }
         #endif
       }   
     }
     et = taosGetTimestampMs();
-    printf("========thread[%"PRIu64"] complete all sqls to super table once queries duration:%.6fs\n\n", (uint64_t)pthread_self(), (double)(et - st)/1000.0);
+    printf("==thread[%"PRIu64"] complete all sqls to specify tables once queries duration:%.6fs\n\n", (uint64_t)pthread_self(), (double)(et - st)/1000.0);
   }
   return NULL;
 }
@@ -4065,7 +4065,7 @@ void *subQueryProcess(void *sarg) {
   char sqlstr[1024];
   threadInfo *winfo = (threadInfo *)sarg; 
   int64_t st = 0;
-  int64_t et = 0;
+  int64_t et = g_queryInfo.subQueryInfo.rate*1000;
   while (1) {
     if (g_queryInfo.subQueryInfo.rate && (et - st) < g_queryInfo.subQueryInfo.rate*1000) {
       taosMsleep(g_queryInfo.subQueryInfo.rate*1000 - (et - st)); // ms
@@ -4085,17 +4085,12 @@ void *subQueryProcess(void *sarg) {
       }
     }
     et = taosGetTimestampMs();
-    printf("========thread[%"PRIu64"] complete all sqls to allocate all sub-tables once queries duration:%.4fs\n\n", (uint64_t)pthread_self(), (double)(et - st)/1000.0);
+    printf("####thread[%"PRIu64"] complete all sqls to allocate all sub-tables[%d - %d] once queries duration:%.4fs\n\n", (uint64_t)pthread_self(), winfo->start_table_id, winfo->end_table_id, (double)(et - st)/1000.0);
   }
   return NULL;
 }
 
 int queryTestProcess() {
-  printfQueryMeta();
-
-  printf("Press enter key to continue\n\n");
-  (void)getchar();
-
   TAOS * taos = NULL;  
   taos_init();
   taos = taos_connect(g_queryInfo.host, g_queryInfo.user, g_queryInfo.password, g_queryInfo.dbName, g_queryInfo.port);
@@ -4108,9 +4103,13 @@ int queryTestProcess() {
     (void)getAllChildNameOfSuperTable(taos, g_queryInfo.dbName, g_queryInfo.subQueryInfo.sTblName, &g_queryInfo.subQueryInfo.childTblName, &g_queryInfo.subQueryInfo.childTblCount);
   }  
   
+  printfQueryMeta();
+  printf("Press enter key to continue\n\n");
+  (void)getchar();
+  
   pthread_t  *pids  = NULL;
   threadInfo *infos = NULL;
-  //==== create sub threads for query from super table
+  //==== create sub threads for query from specify table
   if (g_queryInfo.superQueryInfo.sqlCount > 0 && g_queryInfo.superQueryInfo.concurrent > 0) {
     
     pids  = malloc(g_queryInfo.superQueryInfo.concurrent * sizeof(pthread_t));
@@ -4146,7 +4145,7 @@ int queryTestProcess() {
   
   pthread_t  *pidsOfSub  = NULL;
   threadInfo *infosOfSub = NULL;
-  //==== create sub threads for query from sub table
+  //==== create sub threads for query from all sub table of the super table
   if ((g_queryInfo.subQueryInfo.sqlCount > 0) && (g_queryInfo.subQueryInfo.threadCnt > 0)) {
     pidsOfSub  = malloc(g_queryInfo.subQueryInfo.threadCnt * sizeof(pthread_t));
     infosOfSub = malloc(g_queryInfo.subQueryInfo.threadCnt * sizeof(threadInfo));
@@ -4177,6 +4176,7 @@ int queryTestProcess() {
       
       t_info->start_table_id = last;
       t_info->end_table_id = i < b ? last + a : last + a - 1;
+      last = t_info->end_table_id + 1;
       t_info->taos = taos;
       pthread_create(pidsOfSub + i, NULL, subQueryProcess, t_info);
     }
diff --git a/src/sync/src/syncMain.c b/src/sync/src/syncMain.c
index 98100fbdd87dddc3d9d30431db912813172405b9..1981196525161737255c9807af36c4babc9d20a3 100644
--- a/src/sync/src/syncMain.c
+++ b/src/sync/src/syncMain.c
@@ -568,7 +568,7 @@ static void syncStartCheckPeerConn(SSyncPeer *pPeer) {
   int32_t ret = strcmp(pPeer->fqdn, tsNodeFqdn);
   if (pPeer->nodeId == 0 || (ret > 0) || (ret == 0 && pPeer->port > tsSyncPort)) {
     int32_t checkMs = 100 + (pNode->vgId * 10) % 100;
-    if (pNode->vgId > 1) checkMs = tsStatusInterval * 1000 + checkMs;
+
     sDebug("%s, check peer connection after %d ms", pPeer->id, checkMs);
     taosTmrReset(syncCheckPeerConnection, checkMs, (void *)pPeer->rid, tsSyncTmrCtrl, &pPeer->timer);
   }