diff --git a/include/common/tglobal.h b/include/common/tglobal.h
index 83283cfdad048a932f9df5da0ecf82d4aeeb1280..32cfb5dbaac4fa3524950cb2c00fd2f2f814347b 100644
--- a/include/common/tglobal.h
+++ b/include/common/tglobal.h
@@ -125,6 +125,9 @@ extern SDiskCfg tsDiskCfg[];
 // udf
 extern bool tsStartUdfd;
 
+// schemaless
+extern char tsSmlChildTableName[];
+
 // internal
 extern int32_t tsTransPullupInterval;
 extern int32_t tsMqRebalanceInterval;
diff --git a/source/client/src/clientSml.c b/source/client/src/clientSml.c
index 8fce5bfb00668cdf535d8dacf2e0e12b9e43849a..a18b78b501dd51f5a4b433c3bd2ebbdf2a0c708c 100644
--- a/source/client/src/clientSml.c
+++ b/source/client/src/clientSml.c
@@ -16,6 +16,7 @@
 #include "clientInt.h"
 #include "tname.h"
 #include "cJSON.h"
+#include "tglobal.h"
 //=================================================================================================
 
 #define SPACE ' '
@@ -54,6 +55,9 @@ for (int i = 1; i < keyLen; ++i) {      \
   }                                     \
 }
 
+#define IS_INVALID_COL_LEN(len)   ((len) <= 0 || (len) >= TSDB_COL_NAME_LEN)
+#define IS_INVALID_TABLE_LEN(len) ((len) <= 0 || (len) >= TSDB_TABLE_NAME_LEN)
+
 #define OTD_MAX_FIELDS_NUM      2
 #define OTD_JSON_SUB_FIELDS_NUM 2
 #define OTD_JSON_FIELDS_NUM     4
@@ -899,8 +903,8 @@ static int32_t smlParseInfluxString(const char* sql, SSmlLineInfo *elements, SSm
     sql++;
   }
   elements->measureLen = sql - elements->measure;
-  if(elements->measureLen == 0) {
-    smlBuildInvalidDataMsg(msg, "measure is empty", NULL);
+  if(IS_INVALID_TABLE_LEN(elements->measureLen)) {
+    smlBuildInvalidDataMsg(msg, "measure is empty or too large than 192", NULL);
     return TSDB_CODE_SML_INVALID_DATA;
   }
 
@@ -969,8 +973,9 @@ static void smlParseTelnetElement(const char **sql, const char **data, int32_t *
   }
 }
 
-static int32_t smlParseTelnetTags(const char* data, SArray *cols, SHashObj *dumplicateKey, SSmlMsgBuf *msg){
+static int32_t smlParseTelnetTags(const char* data, SArray *cols, char *childTableName, SHashObj *dumplicateKey, SSmlMsgBuf *msg){
   const char *sql = data;
+  size_t childTableNameLen = strlen(tsSmlChildTableName);
   while(*sql != '\0'){
     JUMP_SPACE(sql)
     if(*sql == '\0') break;
@@ -992,7 +997,7 @@ static int32_t smlParseTelnetTags(const char* data, SArray *cols, SHashObj *dump
       sql++;
     }
 
-    if(keyLen == 0 || keyLen >= TSDB_COL_NAME_LEN){
+    if(IS_INVALID_COL_LEN(keyLen)){
       smlBuildInvalidDataMsg(msg, "invalid key or key is too long than 64", key);
       return TSDB_CODE_SML_INVALID_DATA;
     }
@@ -1022,6 +1027,13 @@ static int32_t smlParseTelnetTags(const char* data, SArray *cols, SHashObj *dump
       return TSDB_CODE_SML_INVALID_DATA;
     }
 
+    //handle child table name
+    if(childTableNameLen != 0 && strncmp(key, tsSmlChildTableName, keyLen) == 0){
+      memset(childTableName, 0, TSDB_TABLE_NAME_LEN);
+      strncpy(childTableName, value, (valueLen < TSDB_TABLE_NAME_LEN ? valueLen : TSDB_TABLE_NAME_LEN));
+      continue;
+    }
+
     // add kv to SSmlKv
     SSmlKv *kv = (SSmlKv *)taosMemoryCalloc(sizeof(SSmlKv), 1);
     if(!kv) return TSDB_CODE_OUT_OF_MEMORY;
@@ -1043,7 +1055,7 @@ static int32_t smlParseTelnetString(SSmlHandle *info, const char* sql, SSmlTable
 
   // parse metric
   smlParseTelnetElement(&sql, &tinfo->sTableName, &tinfo->sTableNameLen);
-  if (!(tinfo->sTableName) || tinfo->sTableNameLen == 0) {
+  if (!(tinfo->sTableName) || IS_INVALID_TABLE_LEN(tinfo->sTableNameLen)) {
     smlBuildInvalidDataMsg(&info->msgBuf, "invalid data", sql);
     return TSDB_CODE_SML_INVALID_DATA;
   }
@@ -1085,7 +1097,7 @@ static int32_t smlParseTelnetString(SSmlHandle *info, const char* sql, SSmlTable
   }
 
   // parse tags
-  ret = smlParseTelnetTags(sql, tinfo->tags, info->dumplicateKey, &info->msgBuf);
+  ret = smlParseTelnetTags(sql, tinfo->tags, tinfo->childTableName, info->dumplicateKey, &info->msgBuf);
   if (ret != TSDB_CODE_SUCCESS) {
     smlBuildInvalidDataMsg(&info->msgBuf, "invalid data", sql);
     return TSDB_CODE_SML_INVALID_DATA;
@@ -1094,7 +1106,7 @@ static int32_t smlParseTelnetString(SSmlHandle *info, const char* sql, SSmlTable
   return TSDB_CODE_SUCCESS;
 }
 
-static int32_t smlParseCols(const char* data, int32_t len, SArray *cols, bool isTag, SHashObj *dumplicateKey, SSmlMsgBuf *msg){
+static int32_t smlParseCols(const char* data, int32_t len, SArray *cols, char *childTableName, bool isTag, SHashObj *dumplicateKey, SSmlMsgBuf *msg){
   if(isTag && len == 0){
     SSmlKv *kv = (SSmlKv *)taosMemoryCalloc(sizeof(SSmlKv), 1);
     if(!kv) return TSDB_CODE_OUT_OF_MEMORY;
@@ -1107,6 +1119,7 @@ static int32_t smlParseCols(const char* data, int32_t len, SArray *cols, bool is
     return TSDB_CODE_SUCCESS;
   }
 
+  size_t childTableNameLen = strlen(tsSmlChildTableName);
   const char *sql = data;
   while(sql < data + len){
     const char *key = sql;
@@ -1126,7 +1139,7 @@ static int32_t smlParseCols(const char* data, int32_t len, SArray *cols, bool is
       sql++;
     }
 
-    if(keyLen == 0 || keyLen >= TSDB_COL_NAME_LEN){
+    if(IS_INVALID_COL_LEN(keyLen)){
       smlBuildInvalidDataMsg(msg, "invalid key or key is too long than 64", key);
       return TSDB_CODE_SML_INVALID_DATA;
     }
@@ -1169,6 +1182,13 @@ static int32_t smlParseCols(const char* data, int32_t len, SArray *cols, bool is
     PROCESS_SLASH(key, keyLen)
     PROCESS_SLASH(value, valueLen)
 
+    //handle child table name
+    if(childTableNameLen != 0 && strncmp(key, tsSmlChildTableName, keyLen) == 0){
+      memset(childTableName, 0, TSDB_TABLE_NAME_LEN);
+      strncpy(childTableName, value, (valueLen < TSDB_TABLE_NAME_LEN ? valueLen : TSDB_TABLE_NAME_LEN));
+      continue;
+    }
+
     // add kv to SSmlKv
     SSmlKv *kv = (SSmlKv *)taosMemoryCalloc(sizeof(SSmlKv), 1);
     if(!kv) return TSDB_CODE_OUT_OF_MEMORY;
@@ -1477,8 +1497,8 @@ static int32_t smlParseMetricFromJSON(SSmlHandle *info, cJSON *root, SSmlTableIn
   }
 
   tinfo->sTableNameLen = strlen(metric->valuestring);
-  if (tinfo->sTableNameLen >= TSDB_TABLE_NAME_LEN) {
-    uError("OTD:0x%"PRIx64" Metric cannot exceeds %d characters in JSON", info->id, TSDB_TABLE_NAME_LEN - 1);
+  if (IS_INVALID_TABLE_LEN(tinfo->sTableNameLen)) {
+    uError("OTD:0x%"PRIx64" Metric lenght is 0 or large than 192", info->id);
     return TSDB_CODE_TSC_INVALID_TABLE_ID_LENGTH;
   }
 
@@ -1828,60 +1848,49 @@ static int32_t smlParseColsFromJSON(cJSON *root, SArray *cols) {
   return TSDB_CODE_SUCCESS;
 }
 
-static int32_t smlParseTagsFromJSON(cJSON *root, SArray *pKVs, SHashObj *dumplicateKey, SSmlMsgBuf *msg) {
+static int32_t smlParseTagsFromJSON(cJSON *root, SArray *pKVs, char *childTableName, SHashObj *dumplicateKey, SSmlMsgBuf *msg) {
   int32_t ret = TSDB_CODE_SUCCESS;
 
   cJSON *tags = cJSON_GetObjectItem(root, "tags");
   if (tags == NULL || tags->type != cJSON_Object) {
     return TSDB_CODE_TSC_INVALID_JSON;
   }
-  //handle child table name  todo
-//  size_t childTableNameLen = strlen(tsSmlChildTableName);
-//  char childTbName[TSDB_TABLE_NAME_LEN] = {0};
-//  if (childTableNameLen != 0) {
-//    memcpy(childTbName, tsSmlChildTableName, childTableNameLen);
-//    cJSON *id = cJSON_GetObjectItem(tags, childTbName);
-//    if (id != NULL) {
-//      if (!cJSON_IsString(id)) {
-//        tscError("OTD:0x%"PRIx64" ID must be JSON string", info->id);
-//        return TSDB_CODE_TSC_INVALID_JSON;
-//      }
-//      size_t idLen = strlen(id->valuestring);
-//      *childTableName = tcalloc(idLen + TS_BACKQUOTE_CHAR_SIZE + 1, sizeof(char));
-//      memcpy(*childTableName, id->valuestring, idLen);
-//      addEscapeCharToString(*childTableName, (int32_t)idLen);
-//
-//      //check duplicate IDs
-//      cJSON_DeleteItemFromObject(tags, childTbName);
-//      id = cJSON_GetObjectItem(tags, childTbName);
-//      if (id != NULL) {
-//        return TSDB_CODE_TSC_DUP_TAG_NAMES;
-//      }
-//    }
-//  }
 
+  size_t childTableNameLen = strlen(tsSmlChildTableName);
   int32_t tagNum = cJSON_GetArraySize(tags);
   for (int32_t i = 0; i < tagNum; ++i) {
     cJSON *tag = cJSON_GetArrayItem(tags, i);
     if (tag == NULL) {
       return TSDB_CODE_TSC_INVALID_JSON;
     }
+    size_t keyLen = strlen(tag->string);
+    if (IS_INVALID_COL_LEN(keyLen)) {
+      uError("OTD:Tag key length is 0 or too large than 64");
+      return TSDB_CODE_TSC_INVALID_COLUMN_LENGTH;
+    }
     //check duplicate keys
-    if (smlCheckDuplicateKey(tag->string, strlen(tag->string), dumplicateKey)) {
+    if (smlCheckDuplicateKey(tag->string, keyLen, dumplicateKey)) {
       return TSDB_CODE_TSC_DUP_TAG_NAMES;
     }
 
+    //handle child table name
+    if(childTableNameLen != 0 && strcmp(tag->string, tsSmlChildTableName) == 0){
+      if (!cJSON_IsString(tag)) {
+        uError("OTD:ID must be JSON string");
+        return TSDB_CODE_TSC_INVALID_JSON;
+      }
+      memset(childTableName, 0, TSDB_TABLE_NAME_LEN);
+      strncpy(childTableName, tag->valuestring, TSDB_TABLE_NAME_LEN);
+      continue;
+    }
+
     // add kv to SSmlKv
     SSmlKv *kv = (SSmlKv *)taosMemoryCalloc(sizeof(SSmlKv), 1);
     if(!kv) return TSDB_CODE_OUT_OF_MEMORY;
     if(pKVs) taosArrayPush(pKVs, &kv);
 
     //key
-    kv->keyLen = strlen(tag->string);
-    if (kv->keyLen >= TSDB_COL_NAME_LEN) {
-      uError("OTD:Tag key cannot exceeds %d characters in JSON", TSDB_COL_NAME_LEN - 1);
-      return TSDB_CODE_TSC_INVALID_COLUMN_LENGTH;
-    }
+    kv->keyLen = keyLen;
     ret = smlJsonCreateSring(&kv->key, tag->string, kv->keyLen);
     if (ret != TSDB_CODE_SUCCESS) {
       return ret;
@@ -1937,7 +1946,7 @@ static int32_t smlParseJSONString(SSmlHandle *info, cJSON *root, SSmlTableInfo *
   uDebug("OTD:0x%"PRIx64" Parse metric value from JSON payload finished", info->id);
 
   //Parse tags
-  ret = smlParseTagsFromJSON(root, tinfo->tags, info->dumplicateKey, &info->msgBuf);
+  ret = smlParseTagsFromJSON(root, tinfo->tags, tinfo->childTableName, info->dumplicateKey, &info->msgBuf);
   if (ret) {
     uError("OTD:0x%"PRIx64" Unable to parse tags from JSON payload", info->id);
     return ret;
@@ -2019,11 +2028,16 @@ static int32_t smlParseInfluxLine(SSmlHandle* info, const char* sql) {
 
     (*oneTable)->sTableName = elements.measure;
     (*oneTable)->sTableNameLen = elements.measureLen;
-    RandTableName rName = { (*oneTable)->tags, (*oneTable)->sTableName, (uint8_t)(*oneTable)->sTableNameLen,
-                           (*oneTable)->childTableName, 0 };
+    if(strlen((*oneTable)->childTableName) == 0){
+      RandTableName rName = { (*oneTable)->tags, (*oneTable)->sTableName, (uint8_t)(*oneTable)->sTableNameLen,
+                             (*oneTable)->childTableName, 0 };
+
+      buildChildTableName(&rName);
+      (*oneTable)->uid = rName.uid;
+    }else{
+      (*oneTable)->uid = *(uint64_t*)((*oneTable)->childTableName);
+    }
 
-    buildChildTableName(&rName);
-    (*oneTable)->uid = rName.uid;
   }
 
   SSmlSTableMeta** tableMeta = (SSmlSTableMeta**)taosHashGet(info->superTables, elements.measure, elements.measureLen);
@@ -2087,10 +2101,15 @@ static int32_t smlParseTelnetLine(SSmlHandle* info, void *data) {
   }
   taosHashClear(info->dumplicateKey);
 
-  RandTableName rName = { tinfo->tags, tinfo->sTableName, (uint8_t)tinfo->sTableNameLen,
-                         tinfo->childTableName, 0 };
-  buildChildTableName(&rName);
-  tinfo->uid = rName.uid;
+  if(strlen(tinfo->childTableName) == 0){
+    RandTableName rName = { tinfo->tags, tinfo->sTableName, (uint8_t)tinfo->sTableNameLen,
+                           tinfo->childTableName, 0 };
+    buildChildTableName(&rName);
+    tinfo->uid = rName.uid;
+  }else{
+    tinfo->uid = *(uint64_t*)(tinfo->childTableName);  // generate uid by name simple
+  }
+
 
   bool hasTable = true;
   SSmlTableInfo **oneTable = (SSmlTableInfo **)taosHashGet(info->childTables, tinfo->childTableName, strlen(tinfo->childTableName));
@@ -2313,9 +2332,9 @@ TAOS_RES* taos_schemaless_insert(TAOS* taos, char* lines[], int numLines, int pr
     return (TAOS_RES*)request;
   }
 
-  if (numLines <= 0 || numLines > 65536) {
+  if (!lines) {
     request->code = TSDB_CODE_SML_INVALID_DATA;
-    smlBuildInvalidDataMsg(&info->msgBuf, "numLines should be between 1 and 65536", NULL);
+    smlBuildInvalidDataMsg(&info->msgBuf, "lines is null", NULL);
     goto end;
   }
 
diff --git a/source/common/src/tglobal.c b/source/common/src/tglobal.c
index aaad606feb878b7e38f52c21fe97cc85434649bc..8a109800e63b5431bcea546399b0a77c73608536 100644
--- a/source/common/src/tglobal.c
+++ b/source/common/src/tglobal.c
@@ -76,6 +76,10 @@ int32_t  tsTelemInterval = 86400;
 char     tsTelemServer[TSDB_FQDN_LEN] = "telemetry.taosdata.com";
 uint16_t tsTelemPort = 80;
 
+// schemaless
+char tsSmlChildTableName[TSDB_TABLE_NAME_LEN] = ""; //user defined child table name can be specified in tag value.
+                                                     //If set to empty system will generate table name using MD5 hash.
+
 // query
 int32_t tsQueryPolicy = 1;
 
@@ -512,6 +516,8 @@ static int32_t taosSetClientCfg(SConfig *pCfg) {
     return -1;
   }
 
+  tstrncpy(tsSmlChildTableName, cfgGetItem(pCfg, "smlChildTableName")->str, TSDB_TABLE_NAME_LEN);
+
   tsShellActivityTimer = cfgGetItem(pCfg, "shellActivityTimer")->i32;
   tsCompressMsgSize = cfgGetItem(pCfg, "compressMsgSize")->i32;
   tsCompressColData = cfgGetItem(pCfg, "compressColData")->i32;