mysql 性能剖析-profiles

一、show profiles
查看profiles功能是否打开

mysql> show variables like 'profiling';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| profiling     | OFF   |
+---------------+-------+
1 row in set (0.03 sec)

在当前会话中打开profiles

mysql> show variables like 'profiling';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| profiling     | OFF   |
+---------------+-------+
1 row in set (0.03 sec)

查询当前会话有哪些sql

show profiles

查询指定sql的详细时间耗费

mysql> show profile for query 3;
+----------------------+----------+
| Status               | Duration |
+----------------------+----------+
| starting             | 0.000087 |
| checking permissions | 0.000017 |
| Opening tables       | 0.000023 |
| init                 | 0.000045 |
| System lock          | 0.000018 |
| optimizing           | 0.000021 |
| statistics           | 0.000075 |
| preparing            | 0.000028 |
| Sorting result       | 0.000016 |
| executing            | 0.000015 |
| Sending data         | 0.000023 |
| Creating sort index  | 0.026676 |
| end                  | 0.000026 |
| query end            | 0.000018 |
| closing tables       | 0.000020 |
| freeing items        | 0.000024 |
| logging slow query   | 0.000038 |
| cleaning up          | 0.000021 |
+----------------------+----------+
18 rows in set, 1 warning (0.04 sec)