1：查看MySQL当前版本是否支持profile
mysql> SELECT @@HAVE_PROFILING;
+------------------+
| @@HAVE_PROFILING |
+------------------+
| YES |
+------------------+
1 row in set (0.00 sec)
2：默认profile是关闭的，查看当前profile是否打开
mysql> SELECT @@PROFILING;
+-------------+
| @@PROFILING |
+-------------+
| 0 |
+-------------+
1 row in set (0.00 sec)
3：打开profile
mysql> SET @@PROFILING = 1;
Query OK, 0 rows affected (0.00 sec)
4：创建环境使用profile
a.创建测试表
mysql> CREATE TABLE T2
-> AS
-> SELECT * FROM mysql.user;
Query OK, 4 rows affected (0.00 sec)
Records: 4 Duplicates: 0 Warnings: 0
b.查看当前语句的ID
mysql> show profiles;
c.查看线程每个状态和执行时间
mysql> show profile for query 25;
+------------------------------+----------+
| Status | Duration |
+------------------------------+----------+
| starting | 0.000050 |
| checking permissions | 0.000006 |
| checking permissions | 0.000005 |
| Opening tables | 0.000115 |
| System lock | 0.000011 |
| init | 0.000095 |
| creating table | 0.005914 |
| After create | 0.000118 |
| System lock | 0.000032 |
| optimizing | 0.000008 |
| statistics | 0.000015 |
| preparing | 0.000012 |
| executing | 0.000004 |
| Sending data | 0.000161 |
| Waiting for query cache lock | 0.000005 |
| Sending data | 0.000676 |
| end | 0.000006 |
| query end | 0.000002 |
| closing tables | 0.000012 |
| freeing items | 0.000190 |
| logging slow query | 0.000003 |
| cleaning up | 0.000004 |
+------------------------------+----------+
22 rows in set (0.00 sec)
