"Actually, the worst part with MySQL is that ActiveRecord have been designed based on it. [...] It is incredibly hard to get other databases working with Rails, and even if you do get them working, it will be slow. Really slow. Take Oracle. Oracle lives and dies by prepared statements. But there is no sane way to do this in Rails.
[...] There are much more important issues in database engineering than normalization, and lets face it, most Rails developers produce pretty crappy databases."