==================================================================
Name

dblink -- Returns a set from a remote database

Synopsis

dblink(text connstr, text sql)
- or -
dblink(text sql)

Inputs

  connstr

    standard libpq format connection string, 
    e.g. "hostaddr=127.0.0.1 port=5432 dbname=mydb user=postgres password=mypasswd"
    If the second form is used, then the dblink_connect(text connstr) must be
    executed first.

  sql

    sql statement that you wish to execute on the remote host
    e.g. "select * from pg_class"

Outputs

  Returns setof record

Example usage

test=# select * from dblink('dbname=template1','select proname, prosrc from pg_proc')
 as t1(proname name, prosrc text) where proname like 'bytea%';
  proname   |   prosrc
------------+------------
 byteacat   | byteacat
 byteaeq    | byteaeq
 bytealt    | bytealt
 byteale    | byteale
 byteagt    | byteagt
 byteage    | byteage
 byteane    | byteane
 byteacmp   | byteacmp
 bytealike  | bytealike
 byteanlike | byteanlike
 byteain    | byteain
 byteaout   | byteaout
(12 rows)

test=# select dblink_connect('dbname=template1');
 dblink_connect
----------------
 OK
(1 row)

test=# select * from dblink('select proname, prosrc from pg_proc')
 as t1(proname name, prosrc text) where proname like 'bytea%';
  proname   |   prosrc
------------+------------
 byteacat   | byteacat
 byteaeq    | byteaeq
 bytealt    | bytealt
 byteale    | byteale
 byteagt    | byteagt
 byteage    | byteage
 byteane    | byteane
 byteacmp   | byteacmp
 bytealike  | bytealike
 byteanlike | byteanlike
 byteain    | byteain
 byteaout   | byteaout
(12 rows)

==================================================================
A more convenient way to use dblink may be to create a view:

 create view myremote_pg_proc as
 select *
 from dblink('dbname=template1','select proname, prosrc from pg_proc')
 as t1(proname name, prosrc text);

Then you can simply write:

   select * from myremote_pg_proc where proname like 'bytea%';