Re: A second qs on multivalued dependencies.
Date: Fri, 15 Oct 2004 14:25:21 -0400
Message-ID: <J9KdnWiNSIODi-3cRVn-3g_at_comcast.com>
"Kostas" <noemail_at_noemail.net> wrote in message
news:10mvv9d6jn83be1_at_corp.supernews.com...
> Yes, u are suggesting again a natural (semantic) key vs. the surrogate
like
> in the previous question. So this is the tendency in this newsgroup? Use
> natural keys?
I have what's probably the minority view in this forum about natural vs. surrogate keys. I think a lot of so called "natural keys" are really surrogate, when viewed from a distance.
In the first place, there are no natural keys to identify people. We all
know why names won't do.
But those people who think that SSN is a "natural" key forget that the
Social Security Administration is not a force of nature.
Just because the SSN is assigned by some clerk at the SSA rather than some
automaton inside the DBMS doesn't make it "natural".
Same for employee_id. A lot of people think this is a surrogate key if IT assigns it, but it's a natural key if HR assigns it. Why?