Right now replicas have the same credentials as the primary database. This limits its usefulness as a way to provide certain people or applications with read-only access. In addition to that, it means the Replica database is incompatible with Ruby on Rails's native "multiple database" functionality as it requires having a distinct user for each database: https://guides.rubyonrails.org/active_record_multiple_databases.html#setting-up-your-application >> Second, the username for the writers and replicas should be different, and the replica user's database permissions should be set to only read and not write. I expect few customers needing to specify their own credentials. Anything that is different from the primary database should suffice both use cases.