My "little application"... a) a needlessly uncivil thing to write b) just the fact that you're (rudely) giving me the religion on CHECK constraints means you'

My "little application"... a) a needlessly uncivil thing to write b) just the fact that you're (rudely) giving me the religion on CHECK constraints means you've probably never actually scaled a DB for high transaction volume. Once you have to start sharding and denormalizing for performance, we've left ACID territory, and most of the validation has to be in the application anyway.