Mysql管理

1.

mysql查询某数据库中各个表的大小

select TABLE_NAME, concat(truncate(data_length/1024/1024,2),' MB') as data_size, concat(truncate(index_length/1024/1024,2),' MB') as index_size from information_schema.tables where TABLE_SCHEMA = '表名' group by TABLE_NAME order by data_length desc;

UPDATE table_name SET field_name = '';

2.

查询mysql当前运行的性能状态语句

mysqladmin -uroot --password='x1#YuMhoNg*' status 

mysqladmin -uroot --password='x1#YuMhoNg*' status -i 5 （每5秒自动刷新一次）

3.

无密码登入mysql

./bin/mysqld_safe --skip-grant-tables 

4.

查看mysql权限

查看权限

select host,user from user ;

5.

mysql清理数据

mysql> DELETE FROM `history_uint` WHERE `clock` < 1327939201;

mysql> optimize table history_uint;