<sect2>

<title>Examples</title>

<para>

Here is an example of creating a foreign table with

<literal>postgres_fdw</>. First install the extension:

</para>

<programlisting>

CREATE EXTENSION postgres_fdw;

</programlisting>

<para>

Then create a foreign server using <xref linkend="sql-createserver">.

In this example we wish to connect to a <productname>PostgreSQL</> server

on host <literal>192.83.123.89</literal> listening on

port <literal>5432</literal>. The database to which the connection is made

is named <literal>foreign_db</literal> on the remote server:

<programlisting>

CREATE SERVER foreign_server

FOREIGN DATA WRAPPER postgres_fdw

OPTIONS (host '192.83.123.89', port '5432', dbname 'foreign_db');

</programlisting>

</para>

<para>

A user mapping, defined with <xref linkend="sql-createusermapping">, is

needed as well to identify the role that will be used on the remote

server:

<programlisting>

CREATE USER MAPPING FOR local_user

SERVER foreign_server

OPTIONS (user 'foreign_user', password 'password');

</programlisting>

</para>

<para>

Now it is possible to create a foreign table with

<xref linkend="sql-createforeigntable">. In this example we

wish to access the table named <structname>some_schema.some_table</>

on the remote server. The local name for it will

be <structname>foreign_table</>:

<programlisting>

CREATE FOREIGN TABLE foreign_table (

id serial NOT NULL,

data text

)

SERVER foreign_server

OPTIONS (schema_name 'some_schema', table_name 'some_table');

</programlisting>

It's essential that the data types and other properties of the columns

declared in <command>CREATE FOREIGN TABLE</> match the actual remote table.

Column names must match as well, unless you attach <literal>column_name</>

options to the individual columns to show how they are named in the remote

table.

</para>

</sect2>