之前在<MySQL sys Schema 简单介绍-1>中简单的介绍了,sys Schema库中的表.那么这些表都可以查询些什么信息呢?接下来本文将做下介绍. 1. 表的情况 1.1 统计下哪些表访问量占前十位 select table_schema,table_name,sum(io_read_requests+io_write_requests) io from schema_table_statistics group by table_schema,table_name order b…
转自:http://www.percona.com/blog/2015/04/16/profiling-mysql-queries-from-performance-schema/ When optimizing queries and investigating performance issues, MySQL comes with built in support for profiling queries aka SET profiling = 1; . This is already…