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Re: Conceptual, Logical, and Physical views of data

From: David Cressey <>
Date: Tue, 13 Sep 2005 03:50:39 GMT
Message-ID: <j0sVe.11051$>

"dawn" <> wrote in message

> > > So, why don't I "get it"?
> >
> > Everything you have said convinces me that your failure to "get it" is
> > due to a lack of intelligence, education, experience, or expertise.
> > you are expressing is "invincible ignorance".
> I don't understand how you could consider me intelligent and yet think
> I am permanently stuck with my ignorance. Again, I don't know what you
> would have me do, say, learn, ...

There are some who cannot learn, and there are others who will not learn.

> >
> > > It isn't that simple. I still think I'm not "getting it" and you are.
> > > I would like to wake up at some point and have it all as clear to me
> > > why all my standard database application data should be modeled
> > > according to relational theory or, if that doesn't happen, have enough
> > > understanding of why I disagree that I can give a rationale that is
> > > more than just "but my experience has been ..." or "but I think ...".
> > >

Why don't you share your understanding with the rest of us?

> >
> > I'm going to repeat what I've said before: I'm no theoretician. If you
> > need a theoretical proof that the relational model is sound, I simply
> > cannot provide that.
> I would like that, but I can see now that is not possible. I'm trying
> to understand where it is tight and where it is not so I can figure out
> why my experience does not match the theory.

Just because I can't provide it doesn't mean that no one in c.d.t. can provide it. There are plenty of theoreticians in here, and they can explain the theory in much more formal and self consistent terms than I can. Over the last two years, several of them have.

> > > And I would be very pleased to hear that explanation (although you
> > > might tell me that you have already provided such -- I really am
> > > memory issues).
> >
> >
> > >
> > > > But I have little, if anything, to teach to you.
> > >
> > > You might feel that way, but I have learned quite a bit from you. If
> > > you say something and I disagree, should I pretend to agree? If I
> > > don't understand how you arrived at a conclusion and want to, should I
> > > refrain from asking? I would think your answers to those questions
> > > would be "no", right?
> > >
> > > > I need not teach you
> > > > anything that you already know to be true. I cannot teach you
> > that
> > > > you already know to be false. What's left?
> > >
> > > I'm hoping you are going to be willing to tell me what you have taught
> > > others is the difference between a pointer and a foreign key. But
> > > I suspect I will have a follow-up question and you will think
> > > like "You can't teach that girl anything!" and we will do the same
> > > dance that you don't enjoy.
> >
> >
> > The stuff I said was very low level introductory stuff. The sort of
> > that would have been learned by people who worked for you on the Oracle
> > projects that you led. I think it's beyond belief that you have not
> > been exposed to everything I could say on the subject.
> OK.
> > All I'm going to suggest is that you go back to some classic work on
> > databases, preferably one that predates the widespread acceptance of the
> > relational model, and read up on the difference between "pinned
> > and "unpinned records". I am sure you can, if you will, learn all that
> > need to learn from that.
> I have never heard the terms "pinned records" and "unpinned records" so
> you might want to retract that "beyond belief" statement ;-) Thanks,
> I'll look those terms up. Cheers! --dawn

On the positive side, Marshall has come up with something I don't think I would have come up with: the concept of outlining the differences between pointers and foreign keys (or, by extension, any similar pair of tools) with some detail and clarity, before tackling the question of which one is "better". That sounds to me like a really productive avenue for dialogue. I expect that, eventually, Marshall and you will find that "better" is more context dependent than "different".

I'm really looking forward to seeing that dialogue play out. It may reach a level of communication that I've been unable to reach. Received on Mon Sep 12 2005 - 22:50:39 CDT

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