Galen Boyer wrote:
> On Mon, 18 Nov 2002, kennedy-family_at_attbi.com wrote:
>
>
>>a surrogate key is an arbitrary key (eg a sequence). A natural
>>key is one that is naturally part of the data (eg in the US the
>>social security number for people)
>
>
> But the social security number was a generated number. Sure,
> mine "means" me, but it was still generated.
>
> Maybe part of the arbitrary argument can be upheld because a
> person designing his database doesn't trust "natural" keys. Most
> database guys aren't, and shouldn't be, very trusting of much.
>
Well, it might be different now ... but when I got my SSN (admitedly a
very long time ago), the first 3 digits indicated what region of the
country you were in when you applied for one. The fact that it has that
wee bit of "smarts" designed into it makes it a natural key. It's not a
truly generated key ... except maybe within the region.
I know some people who know some people who will, for a small fee,
produce a "legal" Social Security Card with a unique SSN. Don't know
where they hijack the numbers from, but it's enuf to fool the IRS. All
this tells me the SSN is not an arbitrary key.
Received on Mon Nov 25 2002 - 10:39:15 CST
