Re: Dreaming About Redesigning SQL
Date: Sat, 25 Oct 2003 23:27:01 -0400
Message-ID: <zdecnfI2y5HOogaiU-KYhg_at_golden.net>
"Marshall Spight" <mspight_at_dnai.com> wrote in message news:nkEmb.29665$Tr4.57087_at_attbi_s03...
> "Bob Badour" <bbadour_at_golden.net> wrote in message
news:uaOdnRNQMrrIZgeiU-KYiw_at_golden.net...
> > >
> > > I think if you reread the sentence you will see that he *does*
> > > consider proximity to be a physical representation. The key
> > > word is "beyond."
> >
> > True. I guess I have to ask: Was there any point to what he wrote?
>
> Well, there's a weird thing going on: order encodes information.
The question is: How do you want to encode order?
If one encodes order as data values in relations, one can use the same notation for manipulating order as for manipulating any other data. If one encodes order using physical position, one must have a whole new notation just for dealing with this additional encoding of information.
> Now, us relationalists (or whatever you call 'em) explicitly say
> we don't care about that
If you refer to relational proponents, I would disagree. Order is important as a collating sequence among values.
> Because of my exposure to the relational model, I'm used to
> thinking of data as being exclusively expressed as values or
> sets. But there's that nagging feeling: there's a whole different
> *kind* of information besides sets.
The set is just a structure within which one represents data--any kind of data.
> Put another way: a set contains less information than an
> ordered set with the same elements.
Only if the elements themselves have no values by which to collate the elements into the desired order. Otherwise, both the ordered set and the unordered set represent identical information.
> That just strikes me
> as bizarre, and although I think I understand the situation,
> I certainly don't understand all the implications of it.
> This different kind of information is truly weird, in
> that it cannot exist without a set to piggyback on.
The information is no different than any other information. The only thing wierd is the representation of the information.
> An ordered empty set contains the same amount
> of information as the regular empty set. Hmmm,
> well, maybe it doesn't. See how weird?
It represents the same information. I see nothing wierd about that. Received on Sun Oct 26 2003 - 04:27:01 CET