I am currently working with some legacy databases that store aggregate values pre-calculated in the tables. Obviously, my domain model doesn't really care about that and aggregates the values on demand during runtime, but when persisting the entities back, I need to save those calculated values.

This leads me to my question of having a write-only attribute on properties. NHibernate would not select the values (or would select the values for update purposes and just not try to set them) and only persist them. Any ideas? I've tried custom types but they don't really fit...