but if this is much improved, i'd hate to see how bad 3.0 was cuz I'm not timpressed at all.
and the docs still say this http://guides.rubyonrails.org/migrations.html
which means they're dead to me8 Active Record and Referential Integrity
The Active Record way claims that intelligence belongs in your models, not in the database. As such, features such as triggers or foreign key constraints, which push some of that intelligence back into the database, are not heavily used.