Using the postgres_fdw extension to access external data

You can access data in a table on a remote database server with the postgres_fdw extension. If you set up a remote connection from your PostgreSQL DB instance, access is also available to your read replica.

To use postgres_fdw to access a remote database server

1. Install the postgres_fdw extension.

   CREATE EXTENSION postgres_fdw;

2. Create a foreign data server using CREATE SERVER.

   CREATE SERVER foreign_server
   FOREIGN DATA WRAPPER postgres_fdw
   OPTIONS (host 'xxx.xx.xxx.xx', port '5432', dbname 'foreign_db'); 

3. Create a user mapping to identify the role to be used on the remote server.

   CREATE USER MAPPING FOR local_user
   SERVER foreign_server
   OPTIONS (user 'foreign_user', password 'password');

4. Create a table that maps to the table on the remote server.

   CREATE FOREIGN TABLE foreign_table (
           id integer NOT NULL,
           data text)
   SERVER foreign_server
   OPTIONS (schema_name 'some_schema', table_name 'some_table');