Re: Surrogate Key vs Production Key

Noons wrote:

> jcelko212_at_earthlink.net (--CELKO--) wrote in message news:<18c7b3c2.0410081648.6958dfc4_at_posting.google.com>...
>
> Oh boy, I wish you were not so verbose and roundabout, Joe.
> Since your days at DBMS magazine nearly 20 years ago, it has
> been a trait of yours.
>
>

>>1) Can I validate the key in itself?  For example, an ISBN has a check
>>digit, I parse a VIN to see that it is in the format with a simple
>>regular expression, etc.
>>
>>2) Can I verify the in the reality I am modeling?  For example, I can
>>read the barcode on the back of a book for the ISBN, I can read the
>>VIN off of the engine block of my car, etc.

And if they do it will be discovered as soon as a duplicate rears its ugly head which is something that should be caught by your code and your constraints.

Use a surrogate key and the mistake is in there forever. Seems to me that you've made our argument for us as well as we did.

-- 
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu
(replace 'x' with 'u' to respond)