Re: Dawn doesn't like 1NF

From: Dan <guntermann_at_verizon.net>
Date: 14 Oct 2004 18:38:22 -0700
Message-ID: <3e68f717.0410141738.5a248ae2_at_posting.google.com>


"Dawn M. Wolthuis" <dwolt_at_tincat-group.comREMOVE> wrote in message news:<ckcqt3$3o1$1_at_news.netins.net>...
> "Laconic2" <laconic2_at_comcast.net> wrote in message
> news:pI2dncO9sK7WpvjcRVn-uQ_at_comcast.com...
> <snip>
>
[snip]

I interject here even at the risk of interrupting the love fest going on in this thread.

> A mathematical relation may certainly have a relation as an element, as well
> as a collection, an ordered tuple, etc. The non-mathematical statement that
> entered into the theory was the statement that since it is simpler to
> exclude non-simple types, then if we can do everything with relations by
> excluding such types, then we ought to take this route in order to have
> simpler mathematics. That is NOT a statement from within mathematics.

Open any basic discrete mathematics textbook of your choosing. Next, turn to the chapter on relations. I challenge you to produce an example problem and solution where relational operators operate over domains of set values, lists, or "non-simple types" with internals exposed. I think you will find that almost all cases specify relations over domains of elements - nothing more, nothing less. Interestingly, this corresponds well with predicate and propositional logic.

That is not to say that these elements might not be something more, such as a set, relation, list, or non-simple type; but even in mathematics, at least at the basic level, structure and manipulative aspects of mathematical relations are 1st order (the element/object level). It's more than Codd.

That being said, I'm also saying that it is not impossible to do what you advocate. It's just that I haven't seen anything thus far that gives as much power for so little complexity. I'm willing to be intellectually honest here. If you show me mathematics where relational operators actually operate on elements of elements, I'll defer.

>
> As I suspect I've said before -- I can use the "mathematical model" of a
> point as a metaphor/model for God or I could use a triangle. Each of these
> metaphors (which is what a mathematical model is) gives some information.
> The fact that a point is simpler than a triangle does not make it the better
> mathematical model for God. Simpler mathematics does not mean better model,
> period.
>
Whatever this means... The implementation of the model can be arbitrarily complex, but the model as it appears to a user of limited bandwidth, should be simple.

> Additionally, what ought we to simplify -- the mathematics? NO! For
> reduced errors we want to make data modeling, design, and use easier (than
> it is today, perhaps?) It might require very complex mathematics to
> simplify the use of databases by humans.

I look forward to hearing and seeing your proposal for alternatives, as I've stated numerous times over the years (and still waiting). I might add that this argument has been going back and forth between object-oriented database and relational proponents for quite a long time.

Your assertion about complexity has been been demonstrated a thousand-fold if you look at this real world example. Unfortunately [for ODBMSs], the value added from implementing such complexity hasn't been enough to justify the expense or the wide-spread interest of the IT community over that of "simpler" models.

So, we don't want to perpetuate
> the old 1NF concepts by continued use of SQL-92 and like products that
> assume no relations or even lists (ordered tuples) within our data models.
>

You know, it was only a year or so back when you would have been (and were) lambasted in this newsgroup for such statements. I certainly hope people understand that this is an opinion, which I respect as such and nothing more, and not necessarily theory.

[Snip]

Regards,

  • Dan
Received on Fri Oct 15 2004 - 03:38:22 CEST

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