CREATE EXTENSION postgres_fdw;
CREATE SERVER some_external_server
    FOREIGN DATA WRAPPER posrtgres_fdw
    OPTIONS (host ‘whatever.host.com’, dbname ‘doreign_db_name’);
CREATE USER MAPPING FOR CURRENT_USER
    SERVER some_external_server
    OPTIONS (USER ‘username’, password ‘password’);

-- map data to a new schema --
CREATE SCHEMA app;
IMPORT FOREIGN SCHEMA PUBLIC
    FROM SERVER some_external_server
    INTO app;

IMPORT FOREIGN SCHEMA foreign_schema
LIMIT TO (table1, table2)
FROM SERVER some_external_server INTO PUBLIC;