mysql也有dblink

mysql也有dblink哟，小姐姐，你没有听过吧，看小哥哥给你测试。

先看看mysql有哪些引擎，凯美瑞是双擎混动，mysql是10个引擎，并且还可以加

先看看mysql版本

mysql> select version();
+-----------+
| version() |
+-----------+
| 5.7.16    |
+-----------+
1 row in set (0.00 sec)

mysql> show engines;
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
| Engine             | Support | Comment                                                        | Transactions | XA   | Savepoints |
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
| MyISAM             | YES     | MyISAM storage engine                                          | NO           | NO   | NO         |
| CSV                | YES     | CSV storage engine                                             | NO           | NO   | NO         |
| PERFORMANCE_SCHEMA | YES     | Performance Schema                                             | NO           | NO   | NO         |
| BLACKHOLE          | YES     | /dev/null storage engine (anything you write to it disappears) | NO           | NO   | NO         |
| MRG_MYISAM         | YES     | Collection of identical MyISAM tables                          | NO           | NO   | NO         |
| InnoDB             | DEFAULT | Supports transactions, row-level locking, and foreign keys     | YES          | YES  | YES        |
| ARCHIVE            | YES     | Archive storage engine                                         | NO           | NO   | NO         |
| MEMORY             | YES     | Hash based, stored in memory, useful for temporary tables      | NO           | NO   | NO         |
| FEDERATED          | NO      | Federated MySQL storage engine                                 | NO           | NO   | NO         |
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+

这里我们用federated就是我们说的dblink类似的功能。远程映射。当前不支持。需要我们修改配置文件。

在/etc/my.cnf 添加

[mysqld]

federated

如下图

[root@slave02 ~]# more /etc/my.cnf
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html
# *** DO NOT EDIT THIS FILE. It's a template which will be copied to the
# *** default location during install, and will be replaced if you
# *** upgrade to a newer version of MySQL.

[mysqld]
federated
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M

重启

[root@slave02 ~]# /etc/init.d/mysqld stop
Shutting down MySQL......                                  [  OK  ]
[root@slave02 ~]# /etc/init.d/mysqld start
Starting MySQL..                                           [  OK  ]

查看是否成功， YES

mysql> show engines;
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
| Engine             | Support | Comment                                                        | Transactions | XA   | Savepoints |
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+
| MyISAM             | YES     | MyISAM storage engine                                          | NO           | NO   | NO         |
| CSV                | YES     | CSV storage engine                                             | NO           | NO   | NO         |
| PERFORMANCE_SCHEMA | YES     | Performance Schema                                             | NO           | NO   | NO         |
| BLACKHOLE          | YES     | /dev/null storage engine (anything you write to it disappears) | NO           | NO   | NO         |
| MRG_MYISAM         | YES     | Collection of identical MyISAM tables                          | NO           | NO   | NO         |
| InnoDB             | DEFAULT | Supports transactions, row-level locking, and foreign keys     | YES          | YES  | YES        |
| ARCHIVE            | YES     | Archive storage engine                                         | NO           | NO   | NO         |
| MEMORY             | YES     | Hash based, stored in memory, useful for temporary tables      | NO           | NO   | NO         |
| FEDERATED          | YES     | Federated MySQL storage engine                                 | NO           | NO   | NO         |
+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+

下面看看，144主机没有ml_1， 然后建立142的映射（类似oracle  dblink， 又类似sql server的透明网关）。

mysql> select count(*) from ml_1;
ERROR 1146 (42S02): Table 'iot.ml_1' doesn't exist
mysql> 
mysql> create table ml_1(
    ->   id int 
    ->  ,age int
    ->  ,school varchar(10)
    ->  ,city varchar(10) 
    ->  ,memo varchar(50)
    ->  ) ENGINE=FEDERATED    
    -> CONNECTION='mysql://root:[email protected]:3306/job_admin/ml_1'; 
Query OK, 0 rows affected (0.12 sec)

mysql> select * from ml_1;
+------+------+--------+--------+--------------------------------------------+
| id   | age  | school | city   | memo                                       |
+------+------+--------+--------+--------------------------------------------+
|    7 |   31 | 本科   | 重庆    | 孟梁,数据库架构师,项目经理,团队管理2年,工作9年   |
+------+------+--------+--------+--------------------------------------------+
1 row in set (0.01 sec)

mysql> 

--end--

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