Re: Is the use of VARCHAR(256) as Primary Keys preferred in Oracle?

From: Paul Brewer <paul_at_paul.brewers.org.uk>
Date: Mon, 18 Nov 2002 20:01:25 -0000
Message-ID: <3dd94d32_3@mk-nntp-1.news.uk.worldonline.com>

"Pablo Sanchez" <pablo_at_dev.null> wrote in message news:Xns92CA6BE7C18D4pingottpingottbah_at_209.242.64.107...
> "Niall Litchfield" <niall.litchfield_at_dial.pipex.com> wrote in
news:3dd91abe$0
> $8513$cc9e4d1f_at_news.dial.pipex.com:
>
> > "Pablo Sanchez" <pablo_at_dev.null> wrote in message
> > news:Xns92C9EFAF939C3pingottpingottbah_at_209.242.64.107...
> >> "Jim Kennedy" <kennedy-family_at_attbi.com> wrote in
> > news:8o%B9.73293$1O2.5806
> >> @sccrnsc04:
> >>
> >> > 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)
> >>
> >> As a side note, SSN's are intended to be unique but are not for a
> >> variety of reasons.
> >
> > A marvellous example of the problems of 'natural keys'.
>
> ... and that was my subtle point! heh heh!
> --
> Pablo Sanchez, High-Performance Database Engineering
> http://www.hpdbe.com

Just a moment guys:

The SSN isn't a natural key; it's just *someone else's surrogate key*. And if they lack even the competence to make their own surrogate key unique, that's a different issue.

Regards,
Paul Received on Mon Nov 18 2002 - 14:01:25 CST