Postgres dblink - Consultando tablas de otra base de datos

With PostgreSQL 9.1 or later, installation of additional modules has been simplified. Registered extensions (including dblink) can be installed with CREATE EXTENSION:

CREATE EXTENSION dblink;

Run once per database. Or run it in the standard system database template1 to add it to every newly created DB automatically. Details in the manual.

Ejemplo:

select t.*
 from dblink('host=localhost dbname=bd user=postgres password=secret', 

                    'select id, name from table')
  as t(id int, name varchar)
 where id < 100
 order by id desc

Mas ejemplos:

http://www.postgresonline.com/journal/archives/44-Using-DbLink-to-access-other-PostgreSQL-Databases-and-Servers.html