How can I create readonly user for backups in PostgreSQL?

Is it true that it is IMPOSSIBLE to create a readonly backup user in PostgreSQL? I've been advised on an IRC channel that you simply can't have a backup only user with no ownership privileges. I find it very strange so I want to make sure I'm not missing something. Below is what I tried but it doesn't give me the results I'm looking for. When I do pg_dump on a given table I'm getting Permission denied for relation...: GRANT SELECT ON ALL TABLES IN SCHEMA public TO backup; ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO backup; GRANT SELECT, USAGE ON ALL SEQUENCES IN SCHEMA public TO backup; ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT, USAGE ON SEQUENCES TO backup; Any help would be greatly appreciated!