Update 04-opentsdb-json.mdx

docs/en/07-develop/03-insert-data/04-opentsdb-json.mdx

@@ -48,7 +48,7 @@ Please refer to [OpenTSDB HTTP API](http://opentsdb.net/docs/build/html/api_http
 
 - In JSON protocol, strings will be converted to NCHAR type and numeric values will be converted to double type.
 - Only data in array format is accepted and so an array must be used even if there is only one row.
-- The defult child table name is generated by rules.You can configure smlChildTableName in taos.cfg to specify child table names, for example, `smlChildTableName=tname`. You can insert `"tags": { "host": "web02","dc": "lga","tname":"cpu1"}` and the cpu1 table will be automatically created. Note that if multiple rows have the same tname but different tag_set values, the tag_set of the first row is used to create the table and the others are ignored.
+- The child table name is created automatically in a rule to guarantee its uniqueness. But you can configure smlChildTableName in taos.cfg to specify a tag value as the table names if the tag value is unique globally. For example, if a tag is called 'tname' and you set `smlChildTableName=tname` in taos.cfg, when you insert `st,tname=cpul,t1=4 c1=3 1626006833639000000`, the child table 'cpus1' will be automatically created. Note that if multiple rows have the same tname but different tag_set values, the tag_set of the first row is used to create the table and the others are ignored.
 :::
 
 ## Examples