which is the Jorge Luis Borges essay with the amusing mention of a system of animal classification: "(a) belonging to the emperor, (b) embalmed, (c) tame ..."
Borges lucidly nails the Achilles' heel - the definition of the database scheme. I stand by my less insightful comment of three weeks ago - care and feeding of 'fact databases' is hard (http://news.ycombinator.com/item?id=520281)