Re: Database design, Keys and some other things

From: David Cressey <david.cressey_at_earthlink.net>
Date: Tue, 27 Sep 2005 12:28:24 GMT
Message-ID: <IVa_e.5794$q1.5601_at_newsread3.news.atl.earthlink.net>


"Marshall Spight" <marshall.spight_at_gmail.com> wrote in message news:1127788646.640736.293230_at_g44g2000cwa.googlegroups.com...

> What's a VIN, then? Are we all imagining them? Are they somehow
> outside of the real world? Is your bank account id somehow
> Not Of This Earth? If you bank account didn't have an id,
> would it be enough to identify it just by the balance?
> "There is a bank account that is a checking account, with
> $1,000,000.00 in it." Could I then authenticate myself to
> the bank by saying, yeah, I'm the guy with the million
> dollars in the bank. If you forgot your balance, would
> that mean you lost access to your money?

A VIN, a bank account number, and an SSN are all surrogate keys. We tend not to recognize them as such because they are created and managed by an agency outside the control of the system we are building or designing. But they are just as artificial as PersonId, created by our system when a "new" person is introduced to the system. Received on Tue Sep 27 2005 - 14:28:24 CEST

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