Oracle FAQ Your Portal to the Oracle Knowledge Grid

Home -> Community -> Usenet -> comp.databases.theory -> Re: Conceptual, Logical, and Physical views of data

Re: Conceptual, Logical, and Physical views of data

From: paul c <>
Date: Sun, 11 Sep 2005 00:42:15 GMT
Message-ID: <H3LUe.460616$5V4.319803@pd7tw3no>

Marshall Spight wrote:


> As an aside, let me just relate that about 2 years ago, I had
> a lengthy discussion at work in which it was me vs. 2 guys with
> CS Ph.Ds, with them taking the position that there's no difference
> between a pointer and a foreign key. At the end of about a week,
> they were unmoved. (Normally that would give me pause, but it
> didn't in this case because I've read a lot more about relational
> theory than they had, and because, well, uh, I'm right. Even
> though: no graduate education <sob>.)

Marshall, as one to another, you are doing fine AFAIAC and thanks for correcting various errors of mine, here as well as giving me food for thought. For me, context is everything and being, admittedly, a relational bigot, I've got no problem with some pointer from somewhere or other being in a relation as long as it is *in* the relation, ie. doesn't violate Codd's Information Principle. I don't care what some other developer's 'meaning' for it is as long as that meaning works in his application and doesn't screw up mine. And I don't think the RM cares either. The meaning of a relation in Codd's sense is by definition external to the RM.

Let the authors with their vested interests try to ram their dogma (which is usually a moving target since their boats will sink fast if they stop chattering and answer the question at hand) down everybody else's throats. I'm not interested in trying to prove it, but I suspect that if one took some of their pronouncements to heart, all logical database development would come to a permanent halt. When it comes to pronouncements about IT, I've found that it helps to ask how the pronouncer earns his or her daily bread when trying to figure out whether they've got their finger on a universal truth or not. I could tell stories about PhD's who left academia for industry and nearly crippled development shops. But I think they were failures in academia first. I could mention fewer PhD's who sped things up. It was the combination of the person and the credentials that really mattered.

As for pointers, I saw an admittedly non-relational system that did tip its hat to some relational notions and materialized main memory with keys that happened to be storage addresses. It was partly 'made out of itself' and this made economic sense. Didn't claim to be complete, but it was pretty darned consistent and I could imagine a really relational system allowing the same thing. However, if somebody else doesn't see it my way, good for them, and let them explain all the costs, short-term and long-term (including loss of data independence) of their better approach (and better it may be in their particular case, especially if the boss and owners don't care about the long-term in which case I'd hope it was a commercial and not a government 'enterprise') to their boss or customer.

p Received on Sat Sep 10 2005 - 19:42:15 CDT

Original text of this message