https://dev.mysql.com/doc/refman/5.7/en/document-store.html
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X plugin是mysql新发版本5.7.12中新增的插件，利用它实现mysql作为文件存储数据库，也就是利用mysql 5.7版本json支持的特性完成，安装很简单，需要下载5.7.12版本并且安装mysqlsh工具。
[[email protected] src]# vim /etc/yum.repos.d/mysql-community.repo [mysql-tools-preview] name=MySQL Tools Preview baseurl=http://repo.mysql.com/yum/mysql-tools-preview/el/6/$basearch/ enabled=1 gpgcheck=0 gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-mysql [[email protected] src]# yum install mysql-shell
这样就可以直接安装上mysqlsh工具，官网给的为gpgcheck=1，但是我这安装需要修改为gpgcheck=0才能正常安装，这个各位自行检查吧。
[[email protected] src]# mysqlsh -u root -h localhost -p --classic --dba enableXProtocol
执行上面命令之后就为mysql安装好X plugin了，可以到mysql查看是否开启
mysql> show plugins; | mysqlx | ACTIVE | DAEMON | mysqlx.so | GPL |
有上面显示的plugin就已正常安装，改插件需要启用单独的协议，所以能看到对应的网络监听端口，默认为33060，现在来进行一些测试
[[email protected] src]# mysqlsh -u root Creating an X Session to [email protected]:33060 Enter password: No default schema selected. Type ‘\help‘, ‘\h‘ or ‘\?‘ for help. Currently in JavaScript mode. Use \sql to switch to SQL mode and execute queries. mysql-js> db; mysql-js>
命令和mongodb类似，现在还没schema和collection，用官网的示例文件world_x-db.zip直接导入
mysqlsh -u root --sql --recreate-schema world_x < /usr/local/src/world_x-db/world_x.sql
Enter password: ****Recreating schema world_x...
[[email protected] src]# mysqlsh -u root -p world_x
mysql-js> db
<Schema:world_x>
mysql-js> db.collections;
{
"CountryInfo": <Collection:CountryInfo>
}
mysql-js> db.CountryInfo.find().limit(1);
[
{
"GNP": 828,
"IndepYear": null,
"Name": "Aruba",
"_id": "ABW",
"demographics": {
"LifeExpectancy": 78.4000015258789,
"Population": 103000
},
"geography": {
"Continent": "North America",
"Region": "Caribbean",
"SurfaceArea": 193
},
"government": {
"GovernmentForm": "Nonmetropolitan Territory of The Netherlands",
"HeadOfState": "Beatrix"
}
}
]
1 document in set (0.00 sec)
mysql-js>
可以看到有点类似于mongodb的操作，现在自己来创建schema和collection进行步骤熟悉
mysql-js> CREATE SCHEMA test_1; SyntaxError: Unexpected identifier at (shell):1:7 in CREATE SCHEMA test_1; ^^^^^^ SyntaxError: Unexpected identifier mysql-js> \q Bye! [[email protected] src]# mysqlsh -u root --recreate-schema test_1 Creating an X Session to [email protected]:33060/test_1 ArgumentError: Recreate schema option can only be used in classic or node sessions [[email protected] src]# mysqlsh -u root --recreate-schema test_1 --sql < aa.sql Enter password: Recreating schema test_1... [[email protected] src]# mysqlsh -u root -p test_1 mysql-js> db <Schema:test_1> mysql-js> \q Bye! [[email protected] src]# cat aa.sql DROP SCHEMA test_1; CREATE SCHEMA test_1;
上面操作可以看出要创建schema只能利用--sql的方式，事先写入到一个sql文件才能正常创建。假如要进行schema切换使用 db = session.getSchema("test_1")，如下：
mysql-js> db;
<Schema:test_1>
mysql-js> db = session.getSchema("world_x");
<Schema:world_x>
下面再来对collection创建操作进行测试：
mysql-js> db;
<Schema:test_1>
mysql-js> db.collections;
{
"CountryInfo": <Collection:CountryInfo>,
"xz_test": <Collection:xz_test>
}
mysql-js> db.createCollection("a");
<Collection:a>
mysql-js> db.collections;
{
"CountryInfo": <Collection:CountryInfo>,
"a": <Collection:a>,
"xz_test": <Collection:xz_test>
}
mysql-js> session.dropCollection("world_x","a");
Query OK (0.00 sec)
mysql-js> db.collections;
{
"CountryInfo": <Collection:CountryInfo>,
"xz_test": <Collection:xz_test>
}
mysql-js>
创建collection和mongodb类似，删除操作有点不同...............对collection的查找、更新、删除和索引添加等操作都有所不同，可以到官网查看有详细的介绍，太长就不写啦。
现在来瞧瞧它是用的什么引擎，原理又是啥.............
[[email protected] src]# mysqlsh -u root -p world_x;
Creating an X Session to [email protected]:33060/world_x
Enter password:
mysql-js> db.collections;
{
"CountryInfo": <Collection:CountryInfo>,
"xz_test": <Collection:xz_test>
}
mysql-js> db.xz_test.find().limit(1);
[
{
"_id": "1a5501cc7efde511d814000c290c4817",
"age": 123,
"name": "xiaozhong"
}
]
1 document in set (0.00 sec)
mysql-js>db.xz_test.createIndex("age").field("age", "INTEGER", false).execute();
Query OK (0.01 sec)
mysql-js>
我这先给我自己创建的测试collection的age字段创建了一个索引，现在直接用mysql连接进去看看结构
[[email protected] src]# mysql -uroot mysql> show databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | | test_1 | | test_a | | world_x | +--------------------+ 7 rows in set (0.00 sec) mysql> use world_x; Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Database changed mysql> show tables; +-------------------+ | Tables_in_world_x | +-------------------+ | City | | Country | | CountryInfo | | CountryLanguage | | xz_test | +-------------------+ 5 rows in set (0.00 sec) mysql> show create table xz_test\G; *************************** 1. row *************************** Table: xz_test Create Table: CREATE TABLE `xz_test` ( `doc` json DEFAULT NULL, `_id` varchar(32) GENERATED ALWAYS AS (json_unquote(json_extract(`doc`,‘$._id‘))) STORED NOT NULL, `$ix_i_F177B50B40803DD7D3962E25071AC5CAA3D1139C` int(11) GENERATED ALWAYS AS (json_extract(`doc`,‘$.age‘)) VIRTUAL, UNIQUE KEY `_id` (`_id`), KEY `age` (`$ix_i_F177B50B40803DD7D3962E25071AC5CAA3D1139C`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 1 row in set (0.00 sec)
由上面的操作可以看出刚才创建的schema和collection都能看到，我刚才创建的age列索引是利用了5.7新特性虚拟列，为_id创建了一个唯一约束并存储到磁盘，利用的innodb引擎，这就可以让collection支持事物行锁等innodb引擎的特性。
总结上面的操作对X plugin特性可以得出：
1、X plugin利用独有的协议可以模拟类似mongodb操作
2、创建schema略显坑
3、全程需要注意大小写
4、可以利用innodb引擎所有特性
5、索引利用虚拟列完成
6、_id字段利用uuid函数生成的数据，去掉了中间连接符"-"，所以在上面加了个unique约束
效率未曾测试，如果有兴趣可以自己测试，官网也有对文档存储的详细介绍，可以自行进行查找。
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