Re: Does Codd's view of a relational database differ from that of Date & Darwin? [M.Gittens]

From: Paul <paul_at_test.com>
Date: Sun, 05 Jun 2005 11:20:37 +0100
Message-ID: <42a2d1f5$0$1694$ed2e19e4@ptn-nntp-reader04.plus.net>

Jan Hidders wrote:

>> Modelling holes in information is straightforward
>> with the use of nulls.  You either have them, or
>> you dont. You could probably replace then with
>> a value, say x, but what would this gain?

>
> It would keep the meta-model simpeler. But that's not the only way to
> model partial information w/o null values and in many cases the worst
> way to do it.

What are better ways to do it? Decomposing relations into several smaller ones as described here?:

http://www.hughdarwen.freeola.com/TheThirdManifesto.web/Missing-info-without-nulls.pdf

Are there other methods?

Why is the "special values in the domain" method inferior to other methods?

Paul. Received on Sun Jun 05 2005 - 05:20:37 CDT