Re: foundations of relational theory?

In article <bn33eu$12j0$1_at_gazette.almaden.ibm.com>, Paul Vernon <paul.vernon_at_ukk.ibmm.comm> writes
>"Dawn M. Wolthuis" <dwolt_at_iserv.net> wrote in message
>news:6db906b2.0310202027.58324c36_at_posting.google.com...
>>
>> I'm likely just getting old, Paul, but I'm not tracking with you on
>> this question. What about my statement gives you a hint that if
>> everything else is equal then an MV system will be less useful and
>> just what is the everything else? You mean if someone has the same
>> number of dollars to sink into an MV syste as an RDBMS system, then
>> the MV system will be less useful? Why?
>
>Because a MV system is more complex (contains more constructs), for no extra
>power than a relational system.

Except that we need far FEWER tables than you do. That means that MV is more SIMPLE than a relational system. How many tables do you need to model an invoice? In a well designed MV system we will have just *one* FILE, that maps EXACTLY to your invoice view.

All your integrity enforcement (cascading delete, can't save order detail without matching order, etc etc etc) just comes as "part of the package" with MV.

By the way, there is *scientific* *proof* that you're wrong in assuming that a dollar spent on MV buys less than a dollar spent on relational. Admittedly there is precious little proof, but what little there is came to the conclusion that a dollar spent on MV bought the same as two dollars spent on relational!
>
>> Also, since IBM has the top-selling MV databases, I hope there are
>> some good IBM discussions on the relative merits of the various data
>> persistence approaches that IBM now sells. I would LOVE to see a
>> breakdown of cost and revenue for IBM on each of its databases. Where
>> would DB2 be compared to Universe, for example? How about IMS?
>> Informix? Is the better bang for the buck for IBM in the relational
>> model or in the non-RDBMS?
>
>I don't know the figures. I know IMS is still non trivial revenue, but DB2
>is where it's really at.

Quoting an IBM press release, 40% of IBM's VAR-related db income comes from IBM's MV databases ...
>
>[snip]
>> > The point of the relational model is that it is *democratic* - i.e. all
>data
>> > is treated equally. Cars have people, people have cars. We do not bias
>> > ourselves one way or another. Children are no more (or less) important
>that
>> > Parents.

And nor do we. The MV model (properly used) treats all entities as equal. What it does NOT do is treat attributes as equal to the entity they describe (which relational does). Relational also treats relations as equal to their entities ...
>>
>> Yup, that is definitely a good point -- the relational model does not
>> retain the same value for the various pieces of propositions that the
>> person stating the proposition did. It elevates less important
>> information to the same status as the subject of a proposition, for
>> example. If Jane Doe fills out a form, then "Jane" simply is more
>> important data than the make of her third car.
>
>Dawn, 'Forms' are mearly one interface into your data. You probably should
>not try to define your data in the terms of a single interface into it. You
>data sould 'stand alone' so to speak.
>
>>
>> > I would urge those who wish to understand more of these issues to read
>Chris
>> > Date's paper "What First Normal Form Really Means" (It will cost you
>> > though )
>> >
>> > http://www.dbdebunk.com/page/page/629796.htm
>> >
>>
>> I would read it, but I've paid for several Date books and decided that
>> instead perhaps he would like to exchange it for the opportunity to
>> read my paper on "Why it Isn't Important to Persist Data in First
>> Normal Form" (you're right -- it is still just in my brain)
>
>I suspect that Fabian won't make such an exchange ;-)
>However, it really is worth your money (assuming you think all this is
>important). It's exactly on the subject that you are working on, and even
>includes an appendix on multi-valued systems.
>If you have a moral objection to paying, let them know. I suspect that
>ultimately they are more interested in spreading knowledge, than making
>money.
>Otherwise, tell Fabin that you commit (on my suggestion) to answering
>Chris's questions in the MV appendix, and he may let you have a free copy.
>
Well, from reading Fabian (and I'd include others in this too), I came to the conclusion that he is incredibly blinkered and bigoted, he has a closed mind, and if he can't understand what you are saying he won't try to work out where you're wrong - he'll simply slag you off as deluded.

That would be okay if he's right, but what's the point of trying to understand him if he can't be bothered to understand you? In those circumstances the only option open is to assume that he must be wrong. Since he has no interest in identifying the flaws in your argument (as opposed to you), then the only tenable conclusion is there are no flaws. Ergo, it's him that's wrong, not you.

Cheers,
Wol

-- 
Anthony W. Youngman - wol at thewolery dot demon dot co dot uk
Witches are curious by definition and inquisitive by nature. She moved in. "Let 
me through. I'm a nosey person.", she said, employing both elbows.
Maskerade : (c) 1995 Terry Pratchett