对数据表进行检查，主要用于 DDL 建表失败的情形。
- 对于拆分表，检查底层物理分表是否有缺失的情况，底层的物理分表的列和索引是否是一致；
- 对于单库单表，检查表是否存在。
语法：
CHECK TABLE tbl_name
mysql> check table tddl_mgr_log;+------------------------+-------+----------+----------+| TABLE | OP | MSG_TYPE | MSG_TEXT |+------------------------+-------+----------+----------+| TDDL5_APP.tddl_mgr_log | check | status | OK |+------------------------+-------+----------+----------+1 row in set (0.56 sec)mysql> check table tddl_mg;+-------------------+-------+----------+----------------------------------------+| TABLE | OP | MSG_TYPE | MSG_TEXT |+-------------------+-------+----------+----------------------------------------+| TDDL5_APP.tddl_mg | check | Error | Table 'tddl5_00.tddl_mg' doesn't exist |+-------------------+-------+----------+----------------------------------------+1 row in set (0.02 sec)
