ENGINES
ENGINES 表提供了关于存储引擎的信息。从和 MySQL 兼容性上考虑,TiDB 会一直将 InnoDB 描述为唯一支持的引擎。此外,ENGINES 表中其它列值也都是定值。
1. USE information_schema;
2. DESC engines;
1. +--------------+-------------+------+------+---------+-------+
2. | Field | Type | Null | Key | Default | Extra |
3. +--------------+-------------+------+------+---------+-------+
4. | ENGINE | varchar(64) | YES | | NULL | |
5. | SUPPORT | varchar(8) | YES | | NULL | |
6. | COMMENT | varchar(80) | YES | | NULL | |
7. | TRANSACTIONS | varchar(3) | YES | | NULL | |
8. | XA | varchar(3) | YES | | NULL | |
9. | SAVEPOINTS | varchar(3) | YES | | NULL | |
10. +--------------+-------------+------+------+---------+-------+
11. 6 rows in set (0.00 sec)
1. SELECT * FROM engines;
1. +--------+---------+------------------------------------------------------------+--------------+------+------------+
2. | ENGINE | SUPPORT | COMMENT | TRANSACTIONS | XA | SAVEPOINTS |
3. +--------+---------+------------------------------------------------------------+--------------+------+------------+
4. | InnoDB | DEFAULT | Supports transactions, row-level locking, and foreign keys | YES | YES | YES |
5. +--------+---------+------------------------------------------------------------+--------------+------+------------+
6. 1 row in set (0.01 sec)
ENGINES 表中列的含义如下:
ENGINE:存储引擎的名称。SUPPORT:服务器对存储引擎的支持级别,在 TiDB 中此值一直是DEFAULT。COMMENT:存储引擎的简要描述。TRANSACTIONS:存储引擎是否支持事务。XA:存储引擎是否支持 XA 事务。SAVEPOINTS:存储引擎是否支持savepoints。
