MySQL--------SQL优化审核工具实战

1. 背景

SQLAdvisor是由美团点评公司技术工程部DBA团队（北京）开发维护的一个分析SQL给出索引优化建议的工具。它基于MySQL原生态词法解析，结合分析SQL中的where条件、聚合条件、多表Join关系 给出索引优化建议。目前SQLAdvisor在美团点评内部广泛应用，公司内部对SQLAdvisor的开发全面转到github上，开源和内部使用保持一致。

在数据库运维过程中，优化SQL是业务团队与DBA团队的日常任务。例行SQL优化，不仅可以提升程序性能，还能够降低线上故障的概率。

目前常用的SQL优化方式包括但不限于：业务层优化、SQL逻辑优化、索引优化等。其中索引优化通常通过调整索引或新增索引从而达到SQL优化的目的。索引优化往往可以在短时间内产生非常巨大的效果。如果能够将索引优化转化成工具化、标准化的流程，减少人工介入的工作量，无疑会大大提高DBA的工作效率。

２. 架构流程图

3. 环境

* os version

[root@SQLAdvisor ~]# cat /etc/redhat-release CentOS release 6.8 (Final)[root@SQLAdvisor ~]# uname -r2.6.32-642.3.1.el6.x86_64[root@SQLAdvisor ~]# uname -nSQLAdvisor[root@SQLAdvisor ~]# getenforce Disabled

* mysql version

mysql> show variables like 'version';+---------------+--------+| Variable_name | Value  |+---------------+--------+| version       | 5.7.18 |+---------------+--------+1 row in set (0.00 sec)

4. 安装SQLAdvisor

* 获取最新代码

[root@SQLAdvisor ~]# git clone https://github.com/Meituan-Dianping/SQLAdvisor.gitInitialized empty Git repository in /root/SQLAdvisor/.git/remote: Counting objects: 1460, done.remote: Total 1460 (delta 0), reused 0 (delta 0), pack-reused 1460Receiving objects: 100% (1460/1460), 19.92 MiB | 209 KiB/s, done.Resolving deltas: 100% (368/368), done.

* 安装依赖项

[root@SQLAdvisor ~]# yum -y  install cmake libaio-devel libffi-devel glib2 glib2-devel[root@SQLAdvisor ~]# yum -y  install  http://www.percona.com/downloads/percona-release/redhat/0.1-3/percona-release-0.1-3.noarch.rpm [root@SQLAdvisor ~]# yum -y  install Percona-Server-shared-56 [root@SQLAdvisor ~]# ln -s /usr/lib64/libperconaserverclient_r.so.18 /usr/lib64/libperconaserverclient_r.so

* 编译依赖项sqlparser

[root@SQLAdvisor ~]# cd SQLAdvisor/[root@SQLAdvisor SQLAdvisor]# cmake -DBUILD_CONFIG=mysql_release -DCMAKE_BUILD_TYPE=debug -DCMAKE_INSTALL_PREFIX=/usr/local/sqlparser ./[root@SQLAdvisor SQLAdvisor]# make && make install

* 安装SQLAdvisor

[root@SQLAdvisor SQLAdvisor]# cd sqladvisor/[root@SQLAdvisor sqladvisor]# cmake -DCMAKE_BUILD_TYPE=debug ./[root@SQLAdvisor sqladvisor]# make

* SQLAdvisor Info

[root@SQLAdvisor sqladvisor]# ./sqladvisor --helpUsage:  sqladvisor [OPTION...] sqladvisorSQL Advisor SummaryHelp Options:  -?, --help              Show help optionsApplication Options:  -f, --defaults-file     sqls file  -u, --username          username  -p, --password          password  -P, --port              port  -h, --host              host  -d, --dbname            database name  -q, --sqls              sqls  -v, --verbose           1:output logs 0:output nothing

5. 测试

* 生成测试数据表

mysql> create database test1 character set utf8mb4;Query OK, 1 row affected (0.00 sec)mysql> create table user(    -> id INT PRIMARY KEY AUTO_INCREMENT,    -> name VARCHAR(64) NOT NULL,    -> age int,    -> sex int    -> )ENGINE=INNODB DEFAULT CHARSET=utf8mb4;Query OK, 0 rows affected (0.13 sec)mysql> desc user;+-------+-------------+------+-----+---------+----------------+| Field | Type        | Null | Key | Default | Extra          |+-------+-------------+------+-----+---------+----------------+| id    | int(11)     | NO   | PRI | NULL    | auto_increment || name  | varchar(64) | NO   |     | NULL    |                || age   | int(11)     | YES  |     | NULL    |                || sex   | int(11)     | YES  |     | NULL    |                |+-------+-------------+------+-----+---------+----------------+4 rows in set (0.01 sec)

* 生成测试数据

mysql> insert into user(name,age, sex) select 'lisea', 25, 1;Query OK, 1 row affected (0.01 sec)Records: 1  Duplicates: 0  Warnings: 0mysql> insert into user(name,age, sex) select concat(name, '1'), age+1, sex+1 from user;Query OK, 1 row affected (0.02 sec)Records: 1  Duplicates: 0  Warnings: 0mysql> insert into user(name,age, sex) select concat(name, '2'), age+2, sex from user;Query OK, 2 rows affected (0.02 sec)Records: 2  Duplicates: 0  Warnings: 0mysql> insert into user(name,age, sex) select concat(name, '3'), age+2, sex from user;Query OK, 4 rows affected (0.18 sec)Records: 4  Duplicates: 0  Warnings: 0......mysql> insert into user(name,age, sex) select concat(name, '10'), age+2, sex from user;Query OK, 512 rows affected (0.24 sec)Records: 512  Duplicates: 0  Warnings: 0mysql> insert into user(name,age, sex) select concat(name, '11'), age+4, sex from user;Query OK, 1024 rows affected (0.79 sec)Records: 1024  Duplicates: 0  Warnings: 0mysql> select count(1) from user;+----------+| count(1) |+----------+|     2048 |+----------+1 row in set (0.01 sec)

* 命令行传参调用测试SQLAdvisor　[查找非索引行]

[root@SQLAdvisor sqladvisor]# ./sqladvisor -h 127.0.0.1  -P 3306  -u root -p '123' -d test1 -q "select * from user where name = 'lisea'" -v 12017-10-27 05:35:49 34059 [Note] 第1步: 对SQL解析优化之后得到的SQL:select `*` AS `*` from `test1`.`user` where (`name` = 'lisea') 2017-10-27 05:35:49 34059 [Note] 第2步：开始解析where中的条件:(`name` = 'lisea') 2017-10-27 05:35:49 34059 [Note] show index from user 2017-10-27 05:35:49 34059 [Note] show table status like 'user' 2017-10-27 05:35:49 34059 [Note] select count(*) from ( select `name` from `user` FORCE INDEX( PRIMARY ) order by id DESC limit 1024) `user` where (`name` = 'lisea')  2017-10-27 05:35:49 34059 [Note] 第3步：表user的行数:2048,limit行数:1024,得到where条件中(`name` = 'lisea')的选择度:1024 2017-10-27 05:35:49 34059 [Note] 第4步：开始验证 字段name是不是主键。表名:user 2017-10-27 05:35:49 34059 [Note] show index from user where Key_name = 'PRIMARY' and Column_name ='name' and Seq_in_index = 1 2017-10-27 05:35:49 34059 [Note] 第5步：字段name不是主键。表名:user 2017-10-27 05:35:49 34059 [Note] 第6步：开始验证 字段name是不是主键。表名:user 2017-10-27 05:35:49 34059 [Note] show index from user where Key_name = 'PRIMARY' and Column_name ='name' and Seq_in_index = 1 2017-10-27 05:35:49 34059 [Note] 第7步：字段name不是主键。表名:user 2017-10-27 05:35:49 34059 [Note] 第8步：开始验证表中是否已存在相关索引。表名:user, 字段名:name, 在索引中的位置:1 2017-10-27 05:35:49 34059 [Note] show index from user where Column_name ='name' and Seq_in_index =1 2017-10-27 05:35:49 34059 [Note] 第9步：开始输出表user索引优化建议: 2017-10-27 05:35:49 34059 [Note] Create_Index_SQL：alter table user add index idx_name(name) 2017-10-27 05:35:49 34059 [Note] 第10步: SQLAdvisor结束!

* 命令行传参调用测试SQLAdvisor　[查找索引行]

[root@SQLAdvisor sqladvisor]# ./sqladvisor -h 127.0.0.1  -P 3306  -u root -p '123' -d test1 -q "select * from user where id = 1" -v 12017-10-27 05:36:46 34062 [Note] 第1步: 对SQL解析优化之后得到的SQL:select `*` AS `*` from `test1`.`user` where (`id` = 1) 2017-10-27 05:36:46 34062 [Note] 第2步：开始解析where中的条件:(`id` = 1) 2017-10-27 05:36:46 34062 [Note] show index from user 2017-10-27 05:36:46 34062 [Note] show table status like 'user' 2017-10-27 05:36:46 34062 [Note] select count(*) from ( select `id` from `user` FORCE INDEX( PRIMARY ) order by id DESC limit 1024) `user` where (`id` = 1)  2017-10-27 05:36:46 34062 [Note] 第3步：表user的行数:2048,limit行数:1024,得到where条件中(`id` = 1)的选择度:1024 2017-10-27 05:36:46 34062 [Note] 第4步：开始验证 字段id是不是主键。表名:user 2017-10-27 05:36:46 34062 [Note] show index from user where Key_name = 'PRIMARY' and Column_name ='id' and Seq_in_index = 1 2017-10-27 05:36:46 34062 [Note] 第5步：字段id是主键。表名:user 2017-10-27 05:36:46 34062 [Note] 第6步：表user 经过运算得到的索引列首列是主键,直接放弃,没有优化建议 2017-10-27 05:36:46 34062 [Note] 第7步: SQLAdvisor结束!

* 配置文件传参调用

[root@SQLAdvisor sqladvisor]# cat sql.cnf [sqladvisor]username=rootpassword=123host=127.0.0.1port=3306dbname=test1sqls=select * from user where name = 'lisea'[root@SQLAdvisor sqladvisor]# ./sqladvisor -f sql.cnf -v 12017-10-27 05:40:14 34070 [Note] 第1步: 对SQL解析优化之后得到的SQL:select `*` AS `*` from `test1`.`user` where (`name` = 'lisea') 2017-10-27 05:40:14 34070 [Note] 第2步：开始解析where中的条件:(`name` = 'lisea') 2017-10-27 05:40:14 34070 [Note] show index from user 2017-10-27 05:40:14 34070 [Note] show table status like 'user' 2017-10-27 05:40:14 34070 [Note] select count(*) from ( select `name` from `user` FORCE INDEX( PRIMARY ) order by id DESC limit 1024) `user` where (`name` = 'lisea')  2017-10-27 05:40:14 34070 [Note] 第3步：表user的行数:2048,limit行数:1024,得到where条件中(`name` = 'lisea')的选择度:1024 2017-10-27 05:40:14 34070 [Note] 第4步：开始验证 字段name是不是主键。表名:user 2017-10-27 05:40:14 34070 [Note] show index from user where Key_name = 'PRIMARY' and Column_name ='name' and Seq_in_index = 1 2017-10-27 05:40:14 34070 [Note] 第5步：字段name不是主键。表名:user 2017-10-27 05:40:14 34070 [Note] 第6步：开始验证 字段name是不是主键。表名:user 2017-10-27 05:40:14 34070 [Note] show index from user where Key_name = 'PRIMARY' and Column_name ='name' and Seq_in_index = 1 2017-10-27 05:40:14 34070 [Note] 第7步：字段name不是主键。表名:user 2017-10-27 05:40:14 34070 [Note] 第8步：开始验证表中是否已存在相关索引。表名:user, 字段名:name, 在索引中的位置:1 2017-10-27 05:40:14 34070 [Note] show index from user where Column_name ='name' and Seq_in_index =1 2017-10-27 05:40:14 34070 [Note] 第9步：开始输出表user索引优化建议: 2017-10-27 05:40:14 34070 [Note] Create_Index_SQL：alter table user add index idx_name(name) 2017-10-27 05:40:14 34070 [Note] 第10步: SQLAdvisor结束!

６. 总结

以需求驱动技术，技术本身没有优略之分，只有业务之分。