MySQL(三) —— MySQL效能優化之 索引優化
阿新 • • 發佈:2018-12-18
MySQL索引優化
如何檢視mysql資料庫的引擎
一般情況下,mysql會預設提供多種儲存引擎,你可以通過下面的檢視: 看mysql支援哪些儲存引擎:
mysql> show engines;
mysql> show engines; +--------------------+---------+----------------------------------------------------------------+--------------+------+------------+ | Engine | Support | Comment | Transactions | XA | Savepoints | +--------------------+---------+----------------------------------------------------------------+--------------+------+------------+ | FEDERATED | NO | Federated MySQL storage engine | NULL | NULL | NULL | | MRG_MYISAM | YES | Collection of identical MyISAM tables | NO | NO | NO | | MyISAM | YES | MyISAM storage engine | NO | NO | NO | | BLACKHOLE | YES | /dev/null storage engine (anything you write to it disappears) | NO | NO | NO | | CSV | YES | CSV storage engine | NO | NO | NO | | MEMORY | YES | Hash based, stored in memory, useful for temporary tables | NO | NO | NO | | ARCHIVE | YES | Archive storage engine | NO | NO | NO | | InnoDB | DEFAULT | Supports transactions, row-level locking, and foreign keys | YES | YES | YES | | PERFORMANCE_SCHEMA | YES | Performance Schema | NO | NO | NO | +--------------------+---------+----------------------------------------------------------------+--------------+------+------------+ 9 rows in set (0.00 sec)
看你的mysql當前預設的儲存引擎: mysql> show variables like '%storage_engine%'; 你要看某個表用了什麼引擎(在顯示結果裡引數engine後面的就表示該表當前用的儲存引擎): mysql> show create table 表名;
mysql> show engines; 看mysql當前預設的儲存引擎: