show variables like '%log%';
set global slow_query_log = 'ON';
set global slow_query_log = 1;
show variables like 'long_query_time';
set global long_query_time = 1;
show variables like 'log_output';
set global log_output='table';
select * from `mysql`.`slow_log` where `db` like '%数据库名%' order by start_time desc;