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INNODB 不支持
mysql> OPTIMIZE TABLE t; +--------+----------+----------+-------------------------------------------------------------------+ | Table | Op | Msg_type | Msg_text | +--------+----------+----------+-------------------------------------------------------------------+ | test.t | optimize | note | Table does not support optimize, doing recreate + analyze instead | //INNODB | test.t | optimize | status | OK | +--------+----------+----------+-------------------------------------------------------------------+ 2 rows in set (0.24 sec)
mysql> show create table t; +-------+-------------------------------------------------------------------------------------------------------------------------------------+ | Table | Create Table | +-------+-------------------------------------------------------------------------------------------------------------------------------------+ | t | CREATE TABLE `t` ( `a` int(11) NOT NULL AUTO_INCREMENT, PRIMARY KEY (`a`) ) ENGINE=InnoDB AUTO_INCREMENT=8 DEFAULT CHARSET=utf8 | +-------+-------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.18 sec)
google:
Everytime you do optimize MySQL, by using mysqlcheck -A -o or using ./mysql_optimize from here.
You may see the output Table does not support optimize, doing recreate + analyze instead. It is because the table that you are using is InnoDB. You can optimize the InnoDB tables by using this. ALTER TABLE table.name ENGINE=‘InnoDB‘; This will create a copy of the original table, and drop the original table, and replace to the original place. Although this is safe, but I suggest you do backup and test first before doing this.
mysql> ALTER TABLE t ENGINE=‘InnoDB‘; Query OK, 0 rows affected (0.29 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> select * from t; +---+ | a | +---+ | 7 | +---+ 1 row in set (0.01 sec)
innodb的数据库不支持optimize，可以用ALTER TABLE table.name ENGINE=‘InnoDB‘; 该方法会对旧表以复制的方式新建一个新表，然后删除旧表。虽然这个过程是安全的, 但是在进行操作时还是先进行备份为好
MyISAM:正常
mysql> show create table t; +-------+-------------------------------------------------------------------------------------------------------------------------------------+ | Table | Create Table | +-------+-------------------------------------------------------------------------------------------------------------------------------------+ | t | CREATE TABLE `t` ( `a` int(11) NOT NULL AUTO_INCREMENT, PRIMARY KEY (`a`) ) ENGINE=MyISAM AUTO_INCREMENT=8 DEFAULT CHARSET=utf8 | +-------+-------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec) mysql> OPTIMIZE TABLE t; +--------+----------+----------+----------+ | Table | Op | Msg_type | Msg_text | +--------+----------+----------+----------+ | test.t | optimize | status | OK | +--------+----------+----------+----------+ 1 row in set (0.00 sec)
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原文地址：http://www.cnblogs.com/zengkefu/p/5636220.html
