Re: Newbie question about db normalization theory: redundant keys OK?

Dr. Dweeb wrote:
> This makes my student number 7613861 artifical?
> This makes my employee number 644923 artificial?
>
> One is used by my university, the other by my employer. They may be
> arbitrarily assigned, but they are unique and indicate me alone.

Well, the student number is unique to you when qualified as "student number at University of X", and the employee number is likewise unique to you when qualified as "employee number at Company Y". However, both numbers are quite likely in use in other contexts to identify things other than you.

And yes, I'd say both numbers are a form of artificial key.

-- 
Jonathan Leffler                   #include <disclaimer.h>
Email: jleffler_at_earthlink.net, jleffler_at_us.ibm.com
Guardian of DBD::Informix v2007.0914 -- http://dbi.perl.org/

publictimestamp.org/ptb/PTB-2045 tiger128 2007-12-17 03:00:04
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