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 -r
2.6.32-642.3.1.el6.x86_64
[root@SQLAdvisor ~]# uname -n
SQLAdvisor
[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.git
Initialized empty Git repository in /root/SQLAdvisor/.git/
remote: Counting objects: 1460, done.
remote: Total 1460 (delta 0), reused 0 (delta 0), pack-reused 1460
Receiving 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 --help
Usage:
sqladvisor [OPTION...] sqladvisor
SQL Advisor Summary
Help Options:
-?, --help Show help options
Application 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: 0
mysql> 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: 0
mysql> 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: 0
mysql> 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
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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: 0
mysql> 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: 0
mysql> 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 1
2017-10-27 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 1
2017-10-27 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=root
password=123
host=127.0.0.1
port=3306
dbname=test1
sqls=select * from user where name = 'lisea'
[root@SQLAdvisor sqladvisor]# ./sqladvisor -f sql.cnf -v 1
2017-10-27 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。