Hi, Hugo.

>>Say the clerk at the front updated the customer city and the one on the back updated the zip code, or in a more typical case, Alice updates the customer Region and Bob updates its Salesperson. Now, both updates are sent to DB, and you get a zip which don't match the city, or a Region not matching the SalesPerson.
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>Shame on you Martín. You should normilize your database! <s>

Well, jokes aside, this is a semantic issue, and doesn't have anything to do with the actual database schema. This is one of the important premises of the Entity Framework. Quite often you have logical entities and sub-entities with specifically related attributes, and then the schema is normalized in a totally different way, for the sake of performance, space, etc. This is where O/R mapping comes into place to be -as Ted Neward says- the Vietnam of Computer Science... <s>

Regards,