CREATE ROLE managers 
    WITH LOGIN ENCRYPTED PASSWORD 'xxxxxx';

GRANT SELECT ON mmk.district TO ROLE managers;
GRANT SELECT ON mmk.houseserial TO ROLE managers;
-- и т.д.

REVOKE ALL ON SCHEMA   mmk FROM managers CASCADE;
REVOKE ALL ON DATABASE mmk FROM managers CASCADE;

DROP ROLE managers;

DROP ROLE managers;

role "managers" cannot be dropped because some objects depend on it
  Подробности: 
access to table mmk.houseserial
access to table mmk.district