小编给大家分享一下MySQL性能分析工具之PROFILE怎么用，相信大部分人都还不怎么了解，因此分享这篇文章给大家参考一下，希望大家阅读完这篇文章后大有收获，下面让我们一起去了解一下吧！

分析SQL执行带来的开销是优化SQL的常用手段，在MySQL数据库中，可以通过配置profiling参数来启用SQL剖析。
它只能在session级别来设置，设置后影响当前session；当它开启后，后续执行的SQL语句都将记录其资源开销，诸如IO，上下文，CPU，MEMORY等。

实验环境：

1. mysql> select version();
   

2. +------------+
   

3. | version() |
   

4. +------------+
   

5. | 5.7.17-log |
   

6. +------------+
   

7. 1 row in set (0.00 sec)

与profile相关的三个参数：

1. mysql> show variables like '%profil%';
   

2. +------------------------+-------+
   

3. | Variable_name | Value |
   

4. +------------------------+-------+
   

5. | have_profiling | YES |                  ---用于控制是否由系统变量开启或禁用profiling
   

6. | profiling | OFF |                       ---开启SQL语句剖析功能
   

7. | profiling_history_size | 15 |           ---设置保留profiling的数目，缺省为15，范围为0至100，为0时将禁用profiling
   

8. +------------------------+-------+
   

9. 3 rows in set (0.01 sec)

开启profiling,有个警告，这个参数在以后会被删除，用information_scheam.PROFILING替代。

1. mysql> set profiling=1;
   

2. Query OK, 0 rows affected, 1 warning (0.00 sec)
   

3. 
   

4. mysql> show warnings;
   +---------+------+----------------------------------------------------------------------+
   | Level   | Code | Message                                                              |
   +---------+------+----------------------------------------------------------------------+
   | Warning | 1287 | '@@profiling' is deprecated and will be removed in a future release. |
   +---------+------+----------------------------------------------------------------------+
   

5. 
   

执行一条sql测试一下:

1. select * from oms3.customers where `type` = 1 AND `status` < 7 AND `isarea` = 6 AND `into_time`>='2016-12-01'AND `into_time`<='2017-01-02 23:59:59' order by score desc limit 40,20

sql执行很慢，执行完成之后查看:

1. mysql> show profiles;
   

2. +----------+--------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   

3. | Query_ID | Duration | Query |
   

4. +----------+--------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
   

5. | 7 | 0.00022275 | SELECT * FROM setup_actors |
   

6. | 8 | 0.00016050 | SELECT DATABASE() |
   

7. | 9 | 0.00032350 | show databases |
   

8. | 10 | 0.00024050 | show tables |
   

9. | 11 | 0.00019250 | SELECT * FROM setup_actors |
   

10. | 12 | 0.00183950 | show variables like "profiling_hist%" |
    

11. | 13 | 0.00192500 | show variables like '%profil%' |
    

12. | 14 | 0.00011550 | show warnings |
    

13. | 15 | 0.00044725 | help 'show profile' |
    

14. | 16 | 0.00013875 | set profiling=1 |
    

15. | 17 | 0.00011550 | show warnings |
    

16. | 18 | 0.00025075 | select * from customers where `type` = 1 AND `status` < 7 AND `isarea` = 6 AND `into_time`>='2016-12-01'AND `into_time`<='2017-01-02 23:59:59' order by score desc limit 40,20 |
    

17. | 19 | 333.19133875 | select * from oms3.customers where `type` = 1 AND `status` < 7 AND `isarea` = 6 AND `into_time`>='2016-12-01'AND `into_time`<='2017-01-02 23:59:59' order by score desc limit 40,20 |
    

18. | 20 | 0.00011250 | show profilings |
    

19. | 21 | 0.00010975 | show profilings |
    

20. +----------+--------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
    

21. 15 rows in set, 1 warning (0.00 sec)
    

22. 
    

23. mysql> set @query_id=19;                ---上面显示是query_id为19
    

24. Query OK, 0 rows affected (0.00 sec)
    

25. 
    

26. mysql> select STATE,sum(duration) as Total_R,          ---用这条sql查询具体是哪里出问题，这条sql引用于《High Performance MySQL,Third Edition》
    

27.     -> ROUND(
    

28.     -> 100*SUM(DURATION)/
    

29.     -> (SELECT SUM(DURATION) FROM INFORMATiON_SCHEMA.PROFILING WHERE QUERY_ID=@query_id),2) as Pct_R,
    

30.     -> count(*) as calls,
    

31.     -> sum(duration)/count(*) as "R/Call"
    

32.     -> from information_schema.profiling
    

33.     -> where query_id=@query_id
    

34.     -> group by state
    

35.     -> order by Total_R desc;
    

36. +----------------------+------------+-------+-------+----------------+
    

37. | STATE | Total_R | Pct_R | calls | R/Call |
    

38. +----------------------+------------+-------+-------+----------------+
    

39. | Sending data | 332.162424 | 99.69 | 1 | 332.1624240000 |         ---这个state基本占用了全部的资源，那么对这条sql的优化就着重于减少io上。
    

40. | statistics | 1.027729 | 0.31 | 1 | 1.0277290000 |
    

41. | Opening tables | 0.000519 | 0.00 | 1 | 0.0005190000 |
    

42. | freeing items | 0.000157 | 0.00 | 1 | 0.0001570000 |
    

43. | starting | 0.000147 | 0.00 | 1 | 0.0001470000 |
    

44. | init | 0.000123 | 0.00 | 1 | 0.0001230000 |
    

45. | logging slow query | 0.000096 | 0.00 | 1 | 0.0000960000 |
    

46. | preparing | 0.000035 | 0.00 | 1 | 0.0000350000 |
    

47. | cleaning up | 0.000019 | 0.00 | 1 | 0.0000190000 |
    

48. | optimizing | 0.000016 | 0.00 | 1 | 0.0000160000 |
    

49. | end | 0.000014 | 0.00 | 1 | 0.0000140000 |
    

50. | System lock | 0.000014 | 0.00 | 1 | 0.0000140000 |
    

51. | closing tables | 0.000013 | 0.00 | 1 | 0.0000130000 |
    

52. | query end | 0.000013 | 0.00 | 1 | 0.0000130000 |
    

53. | Sorting result | 0.000010 | 0.00 | 1 | 0.0000100000 |
    

54. | checking permissions | 0.000009 | 0.00 | 1 | 0.0000090000 |
    

55. | executing | 0.000003 | 0.00 | 1 | 0.0000030000 |
    

56. +----------------------+------------+-------+-------+----------------+
    

57. 17 rows in set, 18 warnings (0.00 sec)

其他用法：

1. mysql> SHOW PROFILE CPU FOR QUERY 2;
   

2. +----------------------+----------+----------+------------+
   

3. | Status | Duration | CPU_user | CPU_system |
   

4. +----------------------+----------+----------+------------+
   

5. | checking permissions | 0.000040 | 0.000038 | 0.000002 |
   

6. | creating table | 0.000056 | 0.000028 | 0.000028 |
   

7. | After create | 0.011363 | 0.000217 | 0.001571 |
   

8. | query end | 0.000375 | 0.000013 | 0.000028 |
   

9. | freeing items | 0.000089 | 0.000010 | 0.000014 |
   

10. | logging slow query | 0.000019 | 0.000009 | 0.000010 |
    

11. | cleaning up | 0.000005 | 0.000003 | 0.000002 |
    

12. +----------------------+----------+----------+------------+

更多用法详见：

help show profiles;

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