I've been developing my DB system for a while and it has a sort of hierarchy to it. There's a parent entity with 15 columns, and there will be around 10 children inheriting therefrom. The children will then each have 15 columns of their own. This semed like a good idea to me, so that the parent and the children would all have their own tables. However, one of my users seemed nonplussed by my system and seemed to prefer a giant, 200-column DB over my system. My question is this: is it worth denormalizing my whole system for the sake of my users, or just tell him to get lost?