There's a better article on the rationale here: http://railstips.org/blog/archives/2011/01/27/data-modeling-in-performant-systems http://railstips.org/blog/arch

There's a better article on the rationale here: http://railstips.org/blog/archives/2011/01/27/data-modeling-in-performant-systems http://railstips.org/blog/archives/2011/01/27/data-modeling-...