[NOVICE] dblink extension to Oracle is it passable

Hi All,

                Is dblink extension can connect to an Oracle instance?  My stapes as following.

1. Create extension dblink
2. CREATE SERVER myserviec FOREIGN DATA WRAPPER dblink_fdw OPTIONS (host 'hostname', dbname 'dbname', port '1521');
3. CREATE USER MAPPING FOR dmtools SERVER myservice OPTIONS (user 'gc92', password 'mypasswd');
4. SELECT dblink_connect('mydbink,'myservice');

Got follow error message:

ERROR:  could not establish connection

DETAIL:  server closed the connection unexpectedly

        This probably means the server terminated abnormally

        before or while processing the request.

Thank you very much,

Garry