mysqlprofile详解对某⼀条sql的性能进⾏分析
查看当前环境的profile设置
show variables like '%profiling%';
+------------------------+-------+
| Variable_name | Value |
+------------------------+-------+
| have_profiling | YES |
| profiling | ON |
| profiling_history_size | 15 |
+------------------------+-------+
3 rows in set (0.00 sec)
开启profile功能
set global profiling = 1;
查看最近sql
show profiles;
+----------+------------+-----------------------------------+
| Query_ID | Duration | Query |
+----------+------------+-----------------------------------+
| 1 | 0.00013100 | select @@version_comment limit 1 |
| 2 | 0.00115800 | show variables like '%profiling%' |
| 3 | 0.00013375 | SELECT DATABASE() |
| 4 | 0.00070625 | show databases |
| 5 | 0.00073675 | show tables |
| 6 | 0.00034975 | select * from student where id=1 |
+----------+------------+-----------------------------------+
6 rows in set, 1 warning (0.00 sec)
查看某⼀条的具体情况
show profile for query 6;
+--------------------------------+----------+
| Status | Duration |
+--------------------------------+----------+
| starting | 0.000082 |
| Executing hook on transaction | 0.000003 |
| starting | 0.000011 |
| checking permissions | 0.000007 |
| Opening tables | 0.000048 |
| init | 0.000009 |安装mysql失败
| System lock | 0.000011 |
| optimizing | 0.000013 |
| statistics | 0.000055 |
| preparing | 0.000014 |
| executing | 0.000013 |
| end | 0.000003 |
| query end | 0.000004 |
| waiting for handler commit | 0.000009 |
| closing tables | 0.000009 |
| freeing items | 0.000015 |
| cleaning up | 0.000045 |
+--------------------------------+----------+
17 rows in set, 1 warning (0.00 sec)
show profile cpu,block io,memory,swaps for query 6;
+--------------------------------+----------+----------+------------+--------------+---------------+-------+
| Status | Duration | CPU_user | CPU_system | Block_ops_in | Block_ops_out | Swaps | +--------------------------------+----------+----------+------------+--------------+---------------+-------+
| starting | 0.000082 | 0.000057 | 0.000024 | 0 | 0 | 0 |
| Executing hook on transaction | 0.000003 | 0.000003 | 0.000001 | 0 | 0 | 0 |
| starting | 0.000011 | 0.000007 | 0.000003 | 0 | 0 | 0 |
| checking permissions | 0.000007 | 0.000005 | 0.000002 | 0 | 0 | 0 |
| Opening tables | 0.000048 | 0.000034 | 0.000014 | 0 | 0 | 0 |
| init | 0.000009 | 0.000006 | 0.000003 | 0 | 0 | 0 |
| System lock | 0.000011 | 0.000008 | 0.000003 | 0 | 0 | 0 |
| optimizing | 0.000013 | 0.000009 | 0.000004 | 0 | 0 | 0 |
| statistics | 0.000055 | 0.000038 | 0.000016 | 0 | 0 | 0 |
| preparing | 0.000014 | 0.000010 | 0.000004 | 0 | 0 | 0 |
| executing | 0.000013 | 0.000010 | 0.000004 | 0 | 0 | 0 |
| end | 0.000003 | 0.000002 | 0.000001 | 0 | 0 | 0 |
| query end | 0.000004 | 0.000002 | 0.000001 | 0 | 0 | 0 |
| waiting for handler commit | 0.000009 | 0.000007 | 0.000003 | 0 | 0 | 0 | | closing tables | 0.000009 | 0.000006 | 0.000002 | 0 | 0 | 0 |
| freeing items | 0.000015 | 0.000010 | 0.000005 | 0 | 0 | 0 |
| cleaning up | 0.000045 | 0.000032 | 0.000013 | 0 | 0 | 0 |
+--------------------------------+----------+----------+------------+--------------+---------------+-------+
17 rows in set, 1 warning (0.00 sec)
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