Re: Order & meaning in a proposition

Oh by the way, congrats on buying the book. That's a pricey one - mine was a Christmas gift, and I probably would have delayed getting it. But I think it's really an outstanding book - even if you don't agree with it, you'll have a precise, informed basis on which to ground your arguments against it.

"Dawn M. Wolthuis" <dwolt_at_tincat-group.com> wrote in message news:c4ss37$lfn$1_at_news.netins.net...
> I broke down and bought the latest Date "An Introduction to Database
> Systems" text. It looks very comprehensive on the one hand and I look
> forward to reading it cover to cover, even though I have read some of it
in
> prior versions.
>
> Without having read the entire book, there still seems to be an aspect
> missing that is integral to understanding data -- language. When taking a
> proposition and normalizing it for the purpose of modeling it, there are
> times when information is inadvertently lost or left behind because it is
> not critical. Sample proposition:
>
> Pat is the host who seated the President and the Secretary of the Interior
>
> If we have a relational model for this proposition, we will end up
splitting
> this proposition up and will undoubtedly lose the order of those who were
> seated. If Pat seated others too, we will also lose the fact that these
two
> seemed to have been seated together or in close proximity of time or
place.
> There is nothing explicit about the ordering, nor is it considered
> important, perhaps, for our software application. However, there is an
> ordering here that is not arbitrary -- the President was listed first as
an
> indication of the relative importance of the two who were seated. Even if
> Pat seated the Secretary of State later, it is likely relevant that such
> information is in a separate proposition from the one above.
>
> Once we split apart a proposition in such a way that we cannot get the
> original proposition back, even if we THINK we are getting the important
> aspects of it back, we have lost some of the meaning we intended to
capture.
>
> This is an off-the-top-of-my-head example of where one might lose
> information when normalizing data and likely not a very good example
> compared to what might be lost in a typical business application.
However,
> the point is that the process of normalizing data makes it sometimes
> impossible to retrieve the original propositions, thereby losing some
> information.
>
> A data modeling process that respects the integrity of the stored
> propositions so that they can be retrieved again has something going for
it
> that the relational model lacks, it seems. Any thoughts? Thanks. --dawn
>
>
Received on Tue Apr 06 2004 - 17:36:02 CEST