果断谷歌，查到一段E文。。。
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.
原来如此，大致意思是说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
还有一种方式：
You can make OPTIMIZE TABLE work on other storage engines by starting mysqld with the --skip-new or --safe-mode option. In this case, OPTIMIZE TABLE is just mapped toALTER TABLE.
上面是说要求我们在启动的时候指定--skip-new或者--safe-mode选项来支持optimize功能
