打开profiling,默认是没开启的.
mysql> set profiling=1;执行要分析的SQL语句
mysql> select count(1) from wechat_employee,Employee;显示profiles表
mysql> show profiles;查询结果：
+----------+------------+-----------------------------------------------+| Query_ID | Duration | Query |+----------+------------+-----------------------------------------------+| 1 | 0.00072975 | select count(1) from wechat_employee,Employee || 2 | 0.00028450 | set profiling=1 || 3 | 0.00324875 | select count(1) from wechat_employee,Employee |+----------+------------+-----------------------------------------------+查询详细信息：
show profile cpu,block io for query 3;结果：
+--------------------------------+----------+----------+------------+--------------+---------------+| Status | Duration | CPU_user | CPU_system | Block_ops_in | Block_ops_out |+--------------------------------+----------+----------+------------+--------------+---------------+| starting | 0.000041 | 0.000000 | 0.000000 | 0 | 0 || Waiting for query cache lock | 0.000073 | 0.000000 | 0.000000 | 0 | 0 || checking query cache for query | 0.000025 | 0.000000 | 0.000000 | 0 | 0 || checking privileges on cached | 0.000023 | 0.000000 | 0.000000 | 0 | 0 || checking permissions | 0.000018 | 0.000000 | 0.000000 | 0 | 0 || checking permissions | 0.000012 | 0.000000 | 0.000000 | 0 | 0 || sending cached result to clien | 0.003009 | 0.000000 | 0.004000 | 0 | 0 || logging slow query | 0.000032 | 0.000000 | 0.000000 | 0 | 0 || cleaning up | 0.000018 | 0.000000 | 0.000000 | 0 | 0 |+--------------------------------+----------+----------+------------+--------------+---------------+9 rows in set (0.00 sec)版权声明：本文为博主原创文章，未经博主允许不得转载。