mysql可以用自带的profile功能查看执行语句需要哪些系统资源,比如cpu,内存,磁盘io之类的,功能默认是关闭状态需手动开启,profile对管理或者开发dba都有很大的帮助.
1.查看profile功能的状态
[[email protected] ~]# /usr/local/mysql-5.6.23/bin/mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 5499
Server version: 5.6.23-log MySQL Community Server (GPL)
Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement.
mysql> show variables like ‘%pro%‘;
+---------------------------+-------+
| Variable_name | Value |
+---------------------------+-------+
| have_profiling | YES |
| profiling | OFF | --默认是关闭状态
| profiling_history_size | 15 |
| protocol_version | 10 |
| proxy_user | |
| slave_compressed_protocol | OFF |
| stored_program_cache | 256 |
+---------------------------+-------+
7 rows in set (0.00 sec)
mysql> set @@profiling=1;
Query OK, 0 rows affected, 1 warning (0.00 sec)
mysql> show variables like ‘%profiling%‘;
+------------------------+-------+
| Variable_name | Value |
+------------------------+-------+
| have_profiling | YES |
| profiling | ON |
| profiling_history_size | 15 |
+------------------------+-------+
3 rows in set (0.00 sec)
mysql> select * from t;
+------+
| a |
+------+
| 1 |
+------+
1 row in set (0.00 sec)
mysql> show profiles;
+----------+------------+-----------------------------------+
| Query_ID | Duration | Query |
+----------+------------+-----------------------------------+
| 1 | 0.00051675 | show variables like ‘%profil%‘ |
| 2 | 0.00052600 | show variables like ‘%profiling%‘ |
| 3 | 0.00010600 | SELECT DATABASE() |
| 4 | 0.00025225 | show databases |
| 5 | 0.00012550 | show tables |
| 6 | 0.00021525 | select * from t |
+----------+------------+-----------------------------------+
6 rows in set, 1 warning (0.00 sec)
mysql> show profile for query 6; --查看Query_ID为6的查询语句所消耗的资源
+----------------------+----------+
| Status | Duration |
+----------------------+----------+
| starting | 0.000058 |
| checking permissions | 0.000007 |
| Opening tables | 0.000020 |
| init | 0.000015 |
| System lock | 0.000010 |
| optimizing | 0.000004 |
| statistics | 0.000012 |
| preparing | 0.000011 |
| executing | 0.000002 |
| Sending data | 0.000037 |
| end | 0.000004 |
| query end | 0.000007 |
| closing tables | 0.000008 |
| freeing items | 0.000010 |
| cleaning up | 0.000012 |
+----------------------+----------+
15 rows in set, 1 warning (0.00 sec)
mysql> show profile BLOCK IO,CPU,MEMORY for query 6;
+----------------------+----------+----------+------------+--------------+---------------+
| Status | Duration | CPU_user | CPU_system | Block_ops_in | Block_ops_out |
+----------------------+----------+----------+------------+--------------+---------------+
| starting | 0.000058 | 0.000000 | 0.000000 | 0 | 0 |
| checking permissions | 0.000007 | 0.000000 | 0.000000 | 0 | 0 |
| Opening tables | 0.000020 | 0.000000 | 0.000000 | 0 | 0 |
| init | 0.000015 | 0.000000 | 0.000000 | 0 | 0 |
| System lock | 0.000010 | 0.000000 | 0.000000 | 0 | 0 |
| optimizing | 0.000004 | 0.000000 | 0.000000 | 0 | 0 |
| statistics | 0.000012 | 0.000000 | 0.000000 | 0 | 0 |
| preparing | 0.000011 | 0.000000 | 0.000000 | 0 | 0 |
| executing | 0.000002 | 0.000000 | 0.000000 | 0 | 0 |
| Sending data | 0.000037 | 0.000000 | 0.000000 | 0 | 0 |
| end | 0.000004 | 0.000000 | 0.000000 | 0 | 0 |
| query end | 0.000007 | 0.000000 | 0.000000 | 0 | 0 |
| closing tables | 0.000008 | 0.000000 | 0.000000 | 0 | 0 |
| freeing items | 0.000010 | 0.000000 | 0.000000 | 0 | 0 |
| cleaning up | 0.000012 | 0.000000 | 0.000000 | 0 | 0 |
+----------------------+----------+----------+------------+--------------+---------------+
15 rows in set, 1 warning (0.00 sec)
mysql> create table t2(a int);
Query OK, 0 rows affected (0.30 sec)
mysql> show profiles;
+----------+------------+-----------------------------------+
| Query_ID | Duration | Query |
+----------+------------+-----------------------------------+
| 1 | 0.00051675 | show variables like ‘%profil%‘ |
| 2 | 0.00052600 | show variables like ‘%profiling%‘ |
| 3 | 0.00010600 | SELECT DATABASE() |
| 4 | 0.00025225 | show databases |
| 5 | 0.00012550 | show tables |
| 6 | 0.00021525 | select * from t |
| 7 | 0.00023775 | help ‘show profile‘ |
| 8 | 0.07420075 | insert into t values(2) |
| 9 | 0.00017425 | create table t1(a int) |
| 10 | 0.29320100 | create table t2(a int) |
+----------+------------+-----------------------------------+
10 rows in set, 1 warning (0.00 sec)
mysql> show profile BLOCK IO,CPU,MEMORY for query 10; --查看Query_ID为10的查询语句所消耗的资源
+----------------------+----------+----------+------------+--------------+---------------+
| Status | Duration | CPU_user | CPU_system | Block_ops_in | Block_ops_out |
+----------------------+----------+----------+------------+--------------+---------------+
| starting | 0.000059 | 0.000000 | 0.000000 | 0 | 0 |
| checking permissions | 0.000007 | 0.000000 | 0.000000 | 0 | 0 |
| Opening tables | 0.000059 | 0.000000 | 0.000000 | 0 | 0 |
| creating table | 0.259481 | 0.002000 | 0.000000 | 0 | 280 |
| After create | 0.000026 | 0.000000 | 0.000000 | 0 | 0 |
| query end | 0.033376 | 0.000000 | 0.000000 | 0 | 8 |
| closing tables | 0.000016 | 0.000000 | 0.000000 | 0 | 0 |
| freeing items | 0.000160 | 0.000000 | 0.000000 | 0 | 0 |
| cleaning up | 0.000018 | 0.000000 | 0.000000 | 0 | 0 |
+----------------------+----------+----------+------------+--------------+---------------+
9 rows in set, 1 warning (0.00 sec)
mysql>