Robert Frasca (3/15/2010)
One of the reasons I don't like de-normalization in the OLTP database is that the business intent of the logical data model can become obfuscated by the perceived need for short-cuts in the physical data model. There is a reason why each entity exists in the normalized data model.
If by denormalisation you mean violating EKNF (or violating 3NF) I agree with you, but if you mean violating one of the higher levels of normalisation (BCNF, 4NF, 5NF) while maintaining EKNF (or even just maintaining 3NF) I have to disagree. The higher normalisations can destroy the ability to use primary key constraints to enforce all the functional dependencies of business data, and denormalisation from them (in cases where they have resulted in something not already required by EKNF) is more often right than wrong. Long live the principle of representability!
Tom