Re: Relations as Repeating Groups & Namespaces

"Alan" <not.me_at_uhuh.rcn.com> wrote in message news:cGQvc.20270$bD4.6152_at_nwrdny02.gnilink.net...
>
> "Dawn M. Wolthuis" <dwolt_at_tincat-group.com> wrote in message
> news:c9o255$ujs$1_at_news.netins.net...
> > "Alan" <alan_at_erols.com> wrote in message
> > news:2i940rFju0m6U1_at_uni-berlin.de...
> > >
> > > "Dawn M. Wolthuis" <dwolt_at_tincat-group.com> wrote in message
> > > news:c9nh8r$i8f$1_at_news.netins.net...
> > <snip>
> > > After you've read this book and/or taken two or three
> > > semesters of graduate level relational database theory, we can talk.
> >
> > Now, son, did you really want to say that? ;-)
>
> You should see what I wrote and didn't send! I was on the fence, and low
on
> caffeine...

and I've been off caffeine for 5 days and 11 hours so far

> >
> > > Note
> > > that I am a practitioner, not a theorist, which is why, as you may
have
> > > noticed, I supply examples rather than enounce theories and discuss
> > proofs.
> >
> > That's just fine -- I've been a practitioner for over a quarter of a
> century
> > and after you have... ;-)
>
> I started in the biz in 1969. I learned IBM 360 assembly language and how
to
> wire (read program) punch card sorters .

OK, I guessed wrong

> >
> > > Having studied the theory (in exhausting detail), I am content that it
> is
> > > internally correct, and can be applied properly to most situations.
> >
> > "Can be" is not an issue. I think that folks like Date and Celko help
the
> > practitioners with various design patterns for handling
less-then-obvious
>
> Agreed.
>
> > implementations and, yes, the relational model, even as implemented in
> > current SQL-DBMS's works. How SHOULD WE do business, is my question.
It
> is
> > obvious that the scope of the relational model is such that it doesn't
> > extend to all best practices within the "data processing" industry. I
> also
> > suspect, but have not proven, that such things as not permitting lists
in
> > the value of an attribute (which has been the case for years with
> > SQL-DBMS's, at least not supporting such with proper
operations/functions
> in
> > the first order predicate logic of the system) are not good ways of
doing
> > business.
>
> Spoken like a true programmer. But, yes, there are some things it is not
> appropriate for. However, the proof is in the pudding.

Yes!

> I've seen relational theory in action as well as other
> > a-relational approaches (which do not rise to the level of mathematical
> > theories yet, in general, although some do). Off the top of my head,
> > without adequate research to back this up -- relational approaches seem
to
> > be big, heavy, brittle, and expensive while other approaches I have used
> > have been more big bang for the buck.
>
> Depends on the implementation, but I would not describe most as "brittle".
> Bang for the buck is very vague. Let's talk real ROI.

But not exactly "agile" (sorry for the buzzword, but the concept is good)

> >
> > > Note
> > > that among scholars, there has been little in the way of major
revisions
> > to
> > > relational theory.
> >
> > Yes, I do note that, but that's gonna change and is changing (knock on
> > wood).
>
> It's been changing for years. Just like the ozone layer. Wake me when
> something important happens. BTW, any real change will be caused by the
next
> significant processor and memory leaps.

I don't think it will take that. I think it is in the wind already. SQL92 still rules in the SQL world and I don't know that subsequent versions will take off. ODBC has been shut down for enhancements for several years. XQuery, whatever you think of it, has Microsoft and IBM on board. Seeing the data the way that XML sees it (not said precisely, I'll admit) is stirring up trouble for the relational model even if the politically correct thing to say is that XML has nothing to do with DBMS's, just with data exchange. Programmers are writing in OO languages or VB (with a little COBOL still making a dent) and none of these languages thinks in relations. The wind is blowing and the storm is getting closer.

> >
> > > There have been extensions and expansions
> > > (object-relational), some refinements (EER) as well as some argument
as
> to
> > > implementation (SQL compliance, E.g.), but no one has said, "Wait a
> > minute -
> > > there has been no definitive discussion. We need to clarify some
things
> > for
> > > everybody."
> >
> > me for one
> >
> > > Except by posters to this newsgroup.
> >
> > I have said these things before the newsgroup and am using this group to
> > learn more and try to figure out the thought processes of those who buy
> > relational theory front to back.
> >
> > > Like those who insist that
> > > data is code or functional dependencies are functions :) Sorry- didn't
> > mean
> > > to open that can 'o worms again, but I couldn't resist a good elbow
jab.
> >
> > Your forgiven - you are young, so you know everything. ;-)
> >
>
> I suspect we are the same age. I may even be older, grasshopper.

I'm 29, no wait, make that 39.

> > > But seriously, if you have $90 to spare, you may want to winch up a
copy
> > of
> > > Elmasri (4th Ed out now). Or maybe hit a campus bookstore and peruse
it.
> > > Bring coffee- there's not much of a plot, and character development
is,
> > > well, not very interesting...
> >
> > You might be shocked to hear how far I would have to drive to put my
hands
> > on a copy of that book shy of buying it.
>
> Contact me directly. I may have a spare.

Rats -- based on your recommendation (along with reading a few others) I ordered a used one from amazon minutes before I read your offer. I needed some summer beach reading anyway.

Cheers! --dawn Received on Fri Jun 04 2004 - 04:39:37 CEST