Primary keys, Surrogate keys and SSN

On Tuesday 12 June 2001 07:11, Koivu, Lisa wrote:
> Well, here's one problem - there is no guarantee that Social Security
> Number will indeed be unique. SS#'s are reassigned, just like phone
> numbers are.

My experience with SSN's in the insurance business is that they make a terrible key.

> IMHO, surrogate keys are always a good idea. Has anyone got an example of
> when a surrogate key is NOT a good idea?

The only real downfall of surrogate keys is that it may require a developer to do a join on the FK to the parent table to get the unique key information.

A small tradeoff in my opinion, since surrogate keys reduce the complexity and column count in joins.

Duhvelopers complain because they have do do *any* joins, but that's to be expected.

Real developers know the benefits.

If we really want to have a full blown discussion on this, we should start a new thread.

Oh look, I just did. :)

Jared

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Author: Jared Still
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