SHOW [STORAGE] ENGINES
SHOW ENGINES显示存储引擎的状态信息。对于检查一个存储引擎是否被支持,或者对于查看默认引擎是什么,本语句十分有用。SHOW TABLE TYPES是同义词,但不赞成使用。
mysql> SHOW ENGINES\G *************************** 1. row *************************** Engine: MyISAM Support: DEFAULT Comment: Default engine as of MySQL 3.23 with great performance *************************** 2. row *************************** Engine: MEMORY Support: YES Comment: Hash based, stored in memory, useful for temporary tables *************************** 3. row *************************** Engine: HEAP Support: YES Comment: Alias for MEMORY *************************** 4. row *************************** Engine: MERGE Support: YES Comment: Collection of identical MyISAM tables *************************** 5. row *************************** Engine: MRG_MYISAM Support: YES Comment: Alias for MERGE *************************** 6. row *************************** Engine: ISAM Support: NO Comment: Obsolete storage engine, now replaced by MyISAM *************************** 7. row *************************** Engine: MRG_ISAM Support: NO Comment: Obsolete storage engine, now replaced by MERGE *************************** 8. row *************************** Engine: InnoDB Support: YES Comment: Supports transactions, row-level locking, and foreign keys *************************** 9. row *************************** Engine: INNOBASE Support: YES Comment: Alias for INNODB *************************** 10. row *************************** Engine: BDB Support: NO Comment: Supports transactions and page-level locking *************************** 11. row *************************** Engine: BERKELEYDB Support: NO Comment: Alias for BDB *************************** 12. row *************************** Engine: NDBCLUSTER Support: DISABLED Comment: Clustered, fault-tolerant, memory-based tables *************************** 13. row *************************** Engine: NDB Support: DISABLED Comment: Alias for NDBCLUSTER *************************** 14. row *************************** Engine: EXAMPLE Support: NO Comment: Example storage engine *************************** 15. row *************************** Engine: ARCHIVE Support: YES Comment: Archive storage engine *************************** 16. row *************************** Engine: CSV Support: YES Comment: CSV storage engine *************************** 17. row *************************** Engine: FEDERATED Support: NO Comment: Federated MySQL storage engine *************************** 18. row *************************** Engine: BLACKHOLE Support: YES Comment: /dev/null storage engine (anything you write to it disappears)
Support值指示某个存储引擎是否被支持,并指示哪个是默认引擎。例如,如果服务器以--default-table-type=InnoDB选项为起始,则InnoDB行的Support值为DEFAULT值。请参见第15章:存储引擎和表类型。