Re: Primary Key

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On Mon, 26 Nov 2007 10:11:37 -0800
Steve Crawford <scrawford(at)pinpointresearch(dot)com> wrote:

> Although I haven't seen it much, recently, semi-trucks used to
> regularly have with numerous plates - one for each state in which
> they operated. And some states such as Texas allow you to have the
> same amateur-radio plate number on multiple vehicles.
>
> I won't argue that there are no reasonable natural keys. But I have
> sure seen plenty of cases where what appeared to be a natural key was
> discovered, generally at a very inopportune time in the development
> process, to be not-so-natural after all.

In "theory" the item that would be a natural key in this instance is
the VIN. You would of course have to make some kind of allowance for
cars that don't have a VIN (nothing in the last what... 50 years?).

Joshua D. Drake

>
> Cheers,
> Steve
>
> ---------------------------(end of
> broadcast)--------------------------- TIP 5: don't forget to increase
> your free space map settings
>

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