简介
mysql profile 工具可以记录执行sql总消耗的时间，并且记录系统cpu和i/o锁消耗的时间。
此工具建议只在开发环境中启动，生产环境应该关闭，减少资源消耗。
使用
/*查看profile配置*/
show variables like "%profiling%";
+------------------------+-------+
| Variable_name | Value |
+------------------------+-------+
| have_profiling | YES |
| profiling | OFF |
| profiling_history_size | 15 |
+------------------------+-------+
/*启动*/
set profiling = 1;
show variables like "%profiling%";
+------------------------+-------+
| Variable_name | Value |
+------------------------+-------+
| have_profiling | YES |
| profiling | ON |
| profiling_history_size | 15 |
+------------------------+-------+
/*查看分析数据*/
show profile for query 3;
+----------------------+----------+
| Status | Duration |
+----------------------+----------+
| starting | 0.000072 |
| checking permissions | 0.000006 |
| Opening tables | 0.000016 |
| init | 0.000014 |
| System lock | 0.000008 |
| optimizing | 0.000004 |
| statistics | 0.000014 |
| preparing | 0.000009 |
| executing | 0.000001 |
| Sending data | 0.013190 |
| end | 0.000011 |
| query end | 0.000009 |
| closing tables | 0.000005 |
| freeing items | 0.000048 |
| cleaning up | 0.000009 |
+----------------------+----------+
show profile all for query 3;
/*主要查看cpu和I/O消耗时间*/
show profile cpu , block io for query 3;
+----------------------+----------+----------+------------+--------------+---------------+
| Status | Duration | CPU_user | CPU_system | Block_ops_in | Block_ops_out |
+----------------------+----------+----------+------------+--------------+---------------+
| starting | 0.000072 | 0.000000 | 0.000000 | NULL | NULL |
| checking permissions | 0.000006 | 0.000000 | 0.000000 | NULL | NULL |
| Opening tables | 0.000016 | 0.000000 | 0.000000 | NULL | NULL |
| init | 0.000014 | 0.000000 | 0.000000 | NULL | NULL |
| System lock | 0.000008 | 0.000000 | 0.000000 | NULL | NULL |
| optimizing | 0.000004 | 0.000000 | 0.000000 | NULL | NULL |
| statistics | 0.000014 | 0.000000 | 0.000000 | NULL | NULL |
| preparing | 0.000009 | 0.000000 | 0.000000 | NULL | NULL |
| executing | 0.000001 | 0.000000 | 0.000000 | NULL | NULL |
| Sending data | 0.013190 | 0.015625 | 0.000000 | NULL | NULL |
| end | 0.000011 | 0.000000 | 0.000000 | NULL | NULL |
| query end | 0.000009 | 0.000000 | 0.000000 | NULL | NULL |
| closing tables | 0.000005 | 0.000000 | 0.000000 | NULL | NULL |
| freeing items | 0.000048 | 0.000000 | 0.000000 | NULL | NULL |
| cleaning up | 0.000009 | 0.000000 | 0.000000 | NULL | NULL |
+----------------------+----------+----------+------------+--------------+---------------+
/*关闭profile*/
set profiling = 0; 
