如何检查mysql表碎片化

select TABLE_NAME, TABLE_SCHEMA, Data_free from information_schema.TABLES where TABLE_SCHEMA NOT IN (‘information_schema‘, ‘mysql‘) and Data_Free >0;

+-----------------+--------------+-----------+
| TABLE_NAME      | TABLE_SCHEMA | Data_free |
+-----------------+--------------+-----------+
| City            | world_innodb |   5242880 |
| City_Copy       | world_innodb |   5242880 |
| Country         | world_innodb |   5242880 |
| CountryLanguage | world_innodb |   5242880 |
| a               | world_innodb |   5242880 |
| t1              | world_innodb |   5242880 |
| t2              | world_innodb |   5242880 |
+-----------------+--------------+-----------+
7 rows in set (0.00 sec)

原文：http://www.cnblogs.com/martinjinyu/p/4310676.html