I agree with everything you said except the "store in two different databases" line. If someone has compromised your system responsible for handling authenticat

I agree with everything you said except the "store in two different databases" line. If someone has compromised your system responsible for handling authentication then presumably they'd have access to both databases regardless - unless you've designed some kind of complex API for generating the salt and secured that API behind a whole different set of security and authentication (which almost everyone is too lazy to do). The salt is just there to stop rainbow tables being generated, and if you're really evil to add computational overhead, it isn't meant to be used in a game of hide and seek.