1.表改名：   mysql> alter table 表名1 rename 表名2;
  例子：mysql>alter table tb1 rename tb2;

2.
创建用户：
CREATE USER 'hx'@ 'localhost' IDENTIFIED BY 'hxpass';
创建用户同时授权：
Grant All on db.* to hx identified by 'hxpass';

修改密码:
set password for hx@localhost = password('hxpass')
update user set password = PASSWORD('hxpass') where user='hx';

删除用户：
DROP USER ''@ 'develop';
DROP USER 'hx'@ 'localhost';
DROP USER 'hx'@ '%';

3.cat /proc/cpuinfo 查看CPU信息
cat /proc/meminfo 查看内存信息