Re: Does Codd's view of a relational database differ from that of Date & Darwin? [M.Gittens]
From: Jan Hidders <jan.hidders_at_REMOVETHIS.pandora.be>
Date: Sun, 05 Jun 2005 17:12:02 GMT
Message-ID: <CnGoe.111636$zs4.6692957_at_phobos.telenet-ops.be>
>
> What are better ways to do it? Decomposing relations into several
> smaller ones as described here?:
>
> http://www.hughdarwen.freeola.com/TheThirdManifesto.web/Missing-info-without-nulls.pdf
Date: Sun, 05 Jun 2005 17:12:02 GMT
Message-ID: <CnGoe.111636$zs4.6692957_at_phobos.telenet-ops.be>
Paul wrote:
> Jan Hidders wrote:
>> [...] 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
Yes. But note that the "better" should be a qualified term here. As always it depends upon many factors whether this is really better or not.
Probably. But I think these are the most important ones.
> Why is the "special values in the domain" method inferior to other
> methods?
Do you always ask that many questions? :-) On this matter I largely agree with Chris Date's position, so I will refer you to his writings.
- Jan Hidders