Re: candidate keys in abstract parent relations
From: paul c <toledobythesea_at_oohay.ac>
Date: Fri, 20 Jan 2006 23:41:11 GMT
Message-ID: <ryeAf.295927$2k.205270_at_pd7tw1no>
>>Roy Hann wrote:
>>
>>>(Names are a bad example for us to use here because they are a poor key
>>>anyway, but let's ignore that.)
>>
>>If names are a poor key, and candidate keys are tied to identity, what
>>are good keys for a named entity (like a person)?
>>
Date: Fri, 20 Jan 2006 23:41:11 GMT
Message-ID: <ryeAf.295927$2k.205270_at_pd7tw1no>
David Cressey wrote:
> "Forrest L Norvell" <spankysyourpal_at_gmail.com> wrote in message > news:1137705821.754921.280830_at_g47g2000cwa.googlegroups.com... >
>>Roy Hann wrote:
>>
>>>(Names are a bad example for us to use here because they are a poor key
>>>anyway, but let's ignore that.)
>>
>>If names are a poor key, and candidate keys are tied to identity, what
>>are good keys for a named entity (like a person)?
>>
> > > Funny you should ask. There aren't any good natural keys for a person.
I'd be interested to hear where the philosophers or mathematicians have been able to define 'identity'. If they can't, I don't see how a computer can. Outside of narrow context, it seems to me to be an indefinable. In fact, in most systems it's not even demonstrable.
Sometimes I think modellers go too far trying to ascribe dbms attributes to the natural world. Certainly big biz and governments do.
p Received on Sat Jan 21 2006 - 00:41:11 CET