Actually, some of the uses I've seen for Cache (http://www.intersystems.com/cache/) are quite functional. It's a pain to work with, at least what little I've done and from what I've read, but as far as scalability, stability, security and performance, it seems to be a very solid product.

Rows and columns are very easy on the human mind. Breaking them down into normal forms takes training, discipline and experience, but the basic concept is easy. On the other hand, in the class object-model, does a door inherit characteristics from a car or is it the other way around? Do all doors have the same methods and properties? Does the presence of a lock on a door come about through polymorphism, or are locks their own object with their own methods and properties? Where does one even start?