True, I'm just not sure that I'd trust the DB isolation once the user has SQL injection. I never saw a SQL injection report on a project (well since the PHP days) ORMs solved this for the most part, but I did see multiple instances of accidental data leaks from bugs on different projects.

It looks like you could also use SET SESSION AUTHORISATION for this but I haven't used it so I don't know how this works with data access/pooling