MySQL Query Profile

MySQL Query Profile MySQL 5.0.37 以上开始支持 MySQL Query Profiler, 可以查询到此 SQL 会执行多少时间, 并看出 CPU/Memory 使用量, 执行过程中 System lock, Table lock 花多少时间等等.

详细可以参见官方文档：Using the New MySQL Query Profiler

http://dev.mysql.com/doc/refman/5.1/en/show-profiles.html

启动

mysql> set profiling=1;

Query OK, 0 rows affected (0.00 sec)

测试查询

mysql> select count(*) from client where broker_id=2;

+----------+

| count(*) |

+----------+

| 200 |

+----------+

1 row in set (0.00 sec)

查看profiles

mysql> show profiles;

+----------+------------+-----------------------------------------------+

| Query_ID | Duration | Query |

+----------+------------+-----------------------------------------------+

| 0 | 0.00007300 | set profiling=1 |

| 1 | 0.00044700 | select count(*) from client where broker_id=2 |

+----------+------------+-----------------------------------------------+

2 rows in set (0.00 sec)

查看单条profile

mysql> show profile for query 1;

+--------------------+------------+

| Status | Duration |

+--------------------+------------+

| (initialization) | 0.00006300 |

| Opening tables | 0.00001400 |

| System lock | 0.00000600 |

| Table lock | 0.00001000 |

| init | 0.00002200 |

| optimizing | 0.00001100 |

| statistics | 0.00009300 |

| preparing | 0.00001700 |

| executing | 0.00000700 |

| Sending data | 0.00016800 |

| end | 0.00000700 |

| query end | 0.00000500 |

| freeing items | 0.00001200 |

| closing tables | 0.00000800 |

| logging slow query | 0.00000400 |

+--------------------+------------+

15 rows in set (0.00 sec)

mysql> alter table t engine=myisam;

Query OK, 112050 rows affected (0.64 sec)

Records: 112050 Duplicates: 0 Warnings: 0

mysql> show profiles;

+----------+------------+-----------------------------------------------+

| Query_ID | Duration | Query |

+----------+------------+-----------------------------------------------+

| 0 | 0.00007300 | set profiling=1 |

| 1 | 0.00044700 | select count(*) from client where broker_id=2 |

| 2 | 0.00003400 | set profiling=0 |

| 3 | 0.00007400 | set profiling=1 |

| 4 | 0.63789700 | alter table t engine=myisam |

| 5 | 0.00004000 | set profiling=0 |

+----------+------------+-----------------------------------------------+

6 rows in set (0.00 sec)

mysql> show profile for query 4;

+----------------------+------------+

| Status | Duration |

+----------------------+------------+

| (initialization) | 0.00002900 |

| checking permissions | 0.00000800 |

| init | 0.00004000 |

| Opening table | 0.00009400 |

| System lock | 0.00000500 |

| Table lock | 0.00000700 |

| setup | 0.00004200 |

| creating table | 0.00195800 |

| After create | 0.00010900 |

| copy to tmp table | 0.52264500 |

| rename result table | 0.11289400 |

| end | 0.00004600 |

| query end | 0.00000700 |

| freeing items | 0.00001300 |

+----------------------+------------+

14 rows in set (0.00 sec)

查看cpu资源等信息

mysql> show profile cpu for query 4;

+----------------------+------------+------------+------------+

| Status | Duration | CPU_user | CPU_system |

+----------------------+------------+------------+------------+

| (initialization) | 0.00002900 | 0.00000000 | 0.00000000 |

| checking permissions | 0.00000800 | 0.00000000 | 0.00000000 |

| init | 0.00004000 | 0.00000000 | 0.00000000 |

| Opening table | 0.00009400 | 0.00100000 | 0.00000000 |

| System lock | 0.00000500 | 0.00000000 | 0.00000000 |

| Table lock | 0.00000700 | 0.00000000 | 0.00000000 |

| setup | 0.00004200 | 0.00000000 | 0.00000000 |

| creating table | 0.00195800 | 0.00000000 | 0.00100000 |

| After create | 0.00010900 | 0.00000000 | 0.00000000 |

| copy to tmp table | 0.52264500 | 0.55591600 | 0.04199300 |

| rename result table | 0.11289400 | 0.00199900 | 0.00000000 |

| end | 0.00004600 | 0.00000000 | 0.00000000 |

| query end | 0.00000700 | 0.00000000 | 0.00000000 |

| freeing items | 0.00001300 | 0.00000000 | 0.00000000 |

+----------------------+------------+------------+------------+

14 rows in set (0.00 sec)

mysql> show profile; 
+--------------------------------+----------+
| Status                         | Duration |
+--------------------------------+----------+
| starting                       | 0.000034 | 
| checking query cache for query | 0.000050 | 
| Opening tables                 | 0.000017 | 
| System lock                    | 0.000005 | 
| Table lock                     | 0.000017 | 
| init                           | 0.000027 | 
| optimizing                     | 0.000006 | 
| statistics                     | 0.000010 | 
| preparing                      | 0.000011 | 
| executing                      | 0.000003 | 
| Sending data                   | 0.000155 | 
| end                            | 0.000010 | 
| query end                      | 0.000003 | 
| freeing items                  | 0.000029 | 
| logging slow query             | 0.000003 | 
| cleaning up                    | 0.000004 | 
+--------------------------------+----------+

其他属性列表

* ALL - displays all information

* BLOCK IO - displays counts for block input and output operations

* CONTEXT SWITCHES - displays counts for voluntary and involuntary context switches

* IPC - displays counts for messages sent and received

* MEMORY - is not currently implemented

* PAGE FAULTS - displays counts for major and minor page faults

* SOURCE - displays the names of functions from the source code, together with the name and line number of the file in which the function occurs

* SWAPS - displays swap counts

设定profiling保存size

mysql> show variables where variable_name='profiling_history_size'; # 默认15条

关闭

mysql> set profiling=0;