Re: Reflections of a beautiful mind... Fundamental principle: Separation of Concerns

From: Bob Badour <>
Date: Tue, 25 Apr 2006 14:19:55 GMT
Message-ID: <feq3g.65561$>

Frank Hamersley wrote:
> Bob Badour wrote:

>> Frank Hamersley wrote:
>>> Bob Badour wrote:
>>>> For instance, the third principle would seem to argue strongly 
>>>> against null and n-vl.
>>> But isn't that the very technique (combinatorial explosion) that
>>> D+D propose with D?
>> You have lost me here. How have they introduced a cominatorial
>> explosion of special cases?

> Nothing said about "special" cases - FWICT they were exploding
> combinatorially for the general case.
> I was referring to the slides Darwen presented at Warwick Uni some time
> ago - "Missing info without nulls" which I perhaps erroneously
> associated with their TTM.
> I particularly like the foot note on page 9 ...
> <quote>
> Nothing wrong with the predicates now! And we have reduced the salary
> part of the database to the simplest possible terms. Yes, some of the
> complicated queries get more difficult now, because we might have to
> combine these tables back together again, but the simple queries, such
> as “How much salary does each person (who has a known salary) earn?” and
> “Who earns no salary?” become trivial.
> </quote>
> To me this triplet of sentences is tantamount to blowing your (sic)
> proverbial foot off with a 155mm field gun even moreso than simply
> selecting a 12 guage shotty for the job.
> But then I could be wrong!

Yes, indeed. Received on Tue Apr 25 2006 - 16:19:55 CEST

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