Re: We claim that delete anomality is due to table not being in 3NF, but...

From: Hugo Kornelis <hugo_at_perFact.REMOVETHIS.info.INVALID>
Date: Sun, 02 Nov 2008 21:42:01 +0100
Message-ID: <l34sg49810rkforc39dqq1peabqn60hnqb_at_4ax.com>


On Fri, 31 Oct 2008 10:47:03 GMT, Walter Mitty wrote:

(snip)
>Even your comment above is way too philosophical for me.
>
>An FD that involves data not stored in the database should NOT be used when
>evaluating conformance to normal forms. There are any number of columns of
>dependent data that are transitively dependent on the primary key via
>intermediate data that is not stored in the DB. As long as there are not
>any transitive dependencies IN THE TABLE, you will not experience any of the
>update anomalies caused by deviation from 3NF.
>
>As far as you can see, looking at the data in the table, the FD is not
>transitive. Whether the FD is transitive in the real world is beyond the
>purview of data normalization.
>

Hi Walter,

You're expressing this so much clearer than I am.

Yes, that was the point I was trying to make.

Best, Hugo Received on Sun Nov 02 2008 - 21:42:01 CET

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