Reading Recommendation on Database Design?

Hi there,

throughout my studies I build all the protoypes with Rails and it was
great fun.
But I never had to build a site with a login and role management, so
now I am a little bit stuck. I searched for a while about
databasedesign but that didn't gave me the results I was looking for,
so that's where you come into play:

Are there any articles, blog posts, books or opensource rails apps
that you can recommend for further studying about that topic? Because
basically I just don't know where to start right now.

I am looking forward to your replies.


You want general db design, or design of a system that does access control via roles?

(For the former, I like _Database Design For Mere Mortals_ by Hernandez.)