select dblink_exec('dbname=mibase host=IP user=usersuport password=xxx',
        'GRANT SELECT on all tables in schema public to myuser;');

CREATE EXTENSION postgres_fdw;

CREATE SERVER servidor_remoto
  FOREIGN DATA WRAPPER postgres_fdw
  OPTIONS (host 'IP', dbname 'mibase');

CREATE USER MAPPING FOR myuser
  SERVER servidor_remoto
  OPTIONS (user 'usersuport', password 'xxx');

IMPORT FOREIGN SCHEMA public
FROM SERVER servidor_remoto
INTO esquema_public_remoto;

GRANT SELECT on all tables in schema esquema_public_remoto to myuser;