MYSQL 使用show profiles 分析性能
Show profiles是5.0.37之后添加的，要想使用此功能，要确保版本在5.0.37之后。如果要使用此功能，先查看mysql版本是否高于5.0.37
查看数据库版本：
mysql> select version();
+-----------+
| version() |
+-----------+
| 5.7.9-log |
+-----------+
1 row in set (0.00 sec)
说明此版本mysql具有此功能。
打开分析工具：
set @@prifileing=1;
执行查询：
mysql> select uid from u_user_master where `id_card` like '%233%';
+-----+
| uid |
+-----+
| 48 |
| 62 |
| 67 |
| 68 |
| 69 |
| 140 |
| 145 |
| 146 |
| 166 |
+-----+
9 rows in set (0.00 sec)
查看mysql性能
mysql> show profiles;
+----------+------------+------------------------------------------------------------+
| Query_ID | Duration | Query |
+----------+------------+------------------------------------------------------------+
| 1 | 0.00033300 | select uid from u_user_master where `id_card` like '%233%' |
| 2 | 0.00005900 | show version() |
| 3 | 0.00013300 | select version() |
| 4 | 0.00041800 | select uid from u_user_master where `id_card` like '%233%' |
+----------+------------+------------------------------------------------------------+
4 rows in set, 1 warning (0.00 sec)
第二列表示查询所用的时间。
根据Query_ID 查看某个查询的详细时间耗费
mysql> show profile for query 4;
+----------------------+----------+
| Status | Duration |
+----------------------+----------+
| starting | 0.000071 |
| checking permissions | 0.000007 |
| Opening tables | 0.000016 |
| init | 0.000023 |
| System lock | 0.000020 |
| optimizing | 0.000010 |
| statistics | 0.000016 |
| preparing | 0.000012 |
| executing | 0.000003 |
| Sending data | 0.000148 |
| end | 0.000005 |
| query end | 0.000006 |
| closing tables | 0.000008 |
| freeing items | 0.000020 |
| logging slow query | 0.000041 |
| cleaning up | 0.000012 |
+----------------------+----------+
16 rows in set, 1 warning (0.00 sec)
查看cpu、IO等信息
mysql> show profile block io, cpu for query 4;
+----------------------+----------+----------+------------+--------------+---------------+
| Status | Duration | CPU_user | CPU_system | Block_ops_in | Block_ops_out |
+----------------------+----------+----------+------------+--------------+---------------+
| starting | 0.000071 | 0.000065 | 0.000005 | 0 | 0 |
| checking permissions | 0.000007 | 0.000005 | 0.000002 | 0 | 0 |
| Opening tables | 0.000016 | 0.000016 | 0.000001 | 0 | 0 |
| init | 0.000023 | 0.000021 | 0.000001 | 0 | 0 |
| System lock | 0.000020 | 0.000009 | 0.000011 | 0 | 0 |
| optimizing | 0.000010 | 0.000009 | 0.000002 | 0 | 0 |
| statistics | 0.000016 | 0.000015 | 0.000001 | 0 | 0 |
| preparing | 0.000012 | 0.000011 | 0.000001 | 0 | 0 |
| executing | 0.000003 | 0.000001 | 0.000001 | 0 | 0 |
| Sending data | 0.000148 | 0.000148 | 0.000001 | 0 | 0 |
| end | 0.000005 | 0.000002 | 0.000002 | 0 | 0 |
| query end | 0.000006 | 0.000006 | 0.000001 | 0 | 0 |
| closing tables | 0.000008 | 0.000007 | 0.000001 | 0 | 0 |
| freeing items | 0.000020 | 0.000008 | 0.000012 | 0 | 0 |
| logging slow query | 0.000041 | 0.000022 | 0.000019 | 0 | 0 |
| cleaning up | 0.000012 | 0.000011 | 0.000001 | 0 | 0 |
+----------------------+----------+----------+------------+--------------+---------------+
16 rows in set, 1 warning (0.00 sec)
更详细的使用参考：https://dev.mysql.com/doc/refman/5.7/en/show-profiles.html
