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Re: identity columns

From: Jan Emil Larsen <jel_at_g-it.dk>
Date: Fri, 11 Jan 2002 13:14:58 +0100
Message-ID: <a1ml03$976$1@news.net.uni-c.dk>

"David Cressey" <david_at_dcressey.com> skrev i en meddelelse news:uqA%7.115$Nq6.5101_at_petpeeve.ziplink.net... <snip>

> In any event, the fact that 13 is the successor of 12 and the fact that
14
> is greater than twelve, is inherent to the reasoning that says "if 12 and
14
> are present, but 13 is not present, it means there is a gap." Now I will
> claim that
> in turn, depends on the following rule: "Invoices are issued in a
> sequence." And that in turn is a small departure from viewing invoices as
a
> set and only as a set.

Thank you for helping to clarify this.

> I'm pointing this out because I think that an excessive demand that
> everything we do be expressed in set theory sometimes leads us to overlook
> valuable possible design features like gap detection. We all know the
> opposite tendency: people who have worked for years with sequential
files,
> and can't think of a table as a set. But sometimes "sequence" is a more
> useful concept than "set" after all. Only sometimes, of course.

I agree; a "set" when ever applicable in the context of the business, but not at any price. Received on Fri Jan 11 2002 - 06:14:58 CST

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