Uncle Bob: Thou shalt not denormalize your data! Casey: Normalized data has an extreme overhead of recalculating things, it's horrible! Reality: You look a

Uncle Bob: Thou shalt not denormalize your data! Casey: Normalized data has an extreme overhead of recalculating things, it's horrible! Reality: You look at the situation and decide when you need cached values to get acceptable performance. (And I consider most denormalized items in the database to be a form of cached value.)