1、没有安装mysql密码插件，执行命令：SHOW VARIABLES LIKE ‘validate_password%’;

2、安装mysql密码插件，执行命令：install plugin validate_password soname ‘validate_password.so’;

3、再次执行：SHOW VARIABLES LIKE ‘validate_password%’;

4、卸载mysql密码插件，执行命令：UNINSTALL PLUGIN validate_password;

5、再次执行命令：SHOW VARIABLES LIKE ‘validate_password%’;