Re: Normalize until neat, Automate until Complete
From: Kenneth Downs <firstinit.lastname_at_lastnameplusfam.net>
Date: Wed, 24 Nov 2004 16:48:19 -0500
Message-ID: <36cf72-m14.ln1_at_pluto.downsfam.net>
>
> Yes, it is. In fact, that is exactly what normalization theory tells us.
> If the redundant columns cannot be updated then there are no update
> anomalies. Therefore theory only requires that the updatable part should
> be normalized if you want to avoid update anomalies.
>
> Don't blame the theorists if the practicioners have only a shallow
> understanding of the theory. :-)
>
Date: Wed, 24 Nov 2004 16:48:19 -0500
Message-ID: <36cf72-m14.ln1_at_pluto.downsfam.net>
Jan Hidders wrote:
>> >> I have a simple question for those who oppose automation on the grounds >> that >> it denormalizes. If normalization is intended to ensure correctness, and >> your system disallows writes to automated columns, have you not preserved >> correctness while also improving the lot of your users? If so, isn't >> that what it's all about?
>
> Yes, it is. In fact, that is exactly what normalization theory tells us.
> If the redundant columns cannot be updated then there are no update
> anomalies. Therefore theory only requires that the updatable part should
> be normalized if you want to avoid update anomalies.
>
> Don't blame the theorists if the practicioners have only a shallow
> understanding of the theory. :-)
>
hmmm, I must be one of those practitioners who has only a shallow understanding of the theory. As far as I can tell, relational algebra and relational calculus are both about querying existing data (though I am willing to be corrected). Under what terms might I find the theoretical foundation for the *generation* of information out of other information?
-- Kenneth Downs <?php $sig_block="Variable scope? What's that?";?>Received on Wed Nov 24 2004 - 22:48:19 CET