Spec-Zone .ru
спецификации, руководства, описания, API
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To create a FEDERATED
table you should follow these steps:
Create the table on the remote server. Alternatively, make a note of the table
definition of an existing table, perhaps using the SHOW CREATE TABLE
statement.
Create the table on the local server with an identical table definition, but adding the connection information that links the local table to the remote table.
For example, you could create the following table on the remote server:
CREATE TABLE test_table ( id INT(20) NOT NULL AUTO_INCREMENT, name VARCHAR(32) NOT NULL DEFAULT '', other INT(20) NOT NULL DEFAULT '0', PRIMARY KEY (id), INDEX name (name), INDEX other_key (other))ENGINE=MyISAMDEFAULT CHARSET=latin1;
To create the local table that will be federated to the remote table, there are two options available. You can
either create the local table and specify the connection string (containing the server name, login, password) to
be used to connect to the remote table using the CONNECTION
, or you can use an
existing connection that you have previously created using the CREATE SERVER
statement.
When you create the local table it must have an identical field definition to the remote table.
You can improve the performance of a FEDERATED
table by adding indexes
to the table on the host. The optimization will occur because the query sent to the remote server will
include the contents of the WHERE
clause and will be sent to the remote server
and subsequently executed locally. This reduces the network traffic that would otherwise request the entire
table from the server for local processing.