MySQL性能分析工具profile使用教程(2)

--启用session级别的profiling 
root@localhost[sakila]> set profiling=1; 
Query OK, 0 rows affected, 1 warning (0.00 sec) 
 
--验证修改后的结果 
root@localhost[sakila]> show variables like '%profil%'; 
+------------------------+-------+ 
| Variable_name          | Value | 
+------------------------+-------+ 
| have_profiling         | YES   | 
| profiling              | ON    | 
| profiling_history_size | 15    | 
+------------------------+-------+ 
 
--发布SQL查询 
root@localhost[sakila]> select count(*) from customer; 
+----------+ 
| count(*) | 
+----------+ 
|      599 | 
+----------+ 
 
--查看当前session所有已产生的profile 
root@localhost[sakila]> show profiles; 
+----------+------------+--------------------------------+ 
| Query_ID | Duration   | Query                          | 
+----------+------------+--------------------------------+ 
|        1 | 0.00253600 | show variables like '%profil%' | 
|        2 | 0.00138150 | select count(*) from customer  | 
+----------+------------+--------------------------------+ 
2 rows in set, 1 warning (0.01 sec) 
 
--我们看到有2个warning，之前一个，现在一个 
root@localhost[sakila]> show warnings;    --下面的结果表明SHOW PROFILES将来会被Performance Schema替换掉 
+---------+------+--------------------------------------------------------------------------------------------------------------+ 
| Level   | Code | Message                                                                                                      | 
+---------+------+--------------------------------------------------------------------------------------------------------------+ 
| Warning | 1287 | 'SHOW PROFILES' is deprecated and will be removed in a future release. Please use Performance Schema instead | 
+---------+------+--------------------------------------------------------------------------------------------------------------+ 

3、获取SQL语句的开销信息

复制代码 代码如下: