Re: Quote of the Week

Em Wed, 12 May 2004 21:52:03 -0700, --CELKO-- escreveu:

> Since Chris Date's version of the
> Relational Model does not have NULLs, he used an arbitrary dummy date
> instead and thus created false information.

        Hm, it is called a special value I guess, and perfectly legitimate.

        Would you care pointing to or posting the details, so we can judge better?

> I sent an email that discussed this problem and a new solution to
> dbdebunk.com which used the SQL-92 OUTER JOIN syntax that did not exist at
> the time of the original publication and a change in the table's DDL.
>
> It was never acknowledged, much less printed.

        I think it was clear enough SQL doesn't interest them much, except as a bad example.

> 2) I made a remark in one of my books that SQL cannot technically violate
> 1NF because all columns are scalar datatypes. That was followed by
> detailed remarks as to how programmers are so used to thinking in terms of
> arrays and lists that they "fake it" with various tricks (numbered column
> names, strings of Comma separated values, etc.)
>
> The qualification was removed when I was quotes on dbdebunk, completely
> mis-representing my position. Then in a reply to an email on 1NF, Fabian
> made reference to the same kind of thinking!

        Perhaps it's too early in the morning, but I didn't quite follow this.

> 3) He still advocates an adjacency model for trees. Unfortunately, he
> does not given all the constraints needed to assure that such a table is
> actually a tree and not a general graph, nor does he mention that you
> **must** use procedural code to manipulate that model. In short, it is
> the worst way to model a tree in a set-oriented language, but to give it
> up he would have to acknowledge either path enumeration or nested sets
> models, and that he missed it.

        Actually I am at his side in this. I don't see how your solution is less procedural than his, and his is certainly simpler.

        But perhaps it is that can't be smarty enough to understand you...

> 4) He supports Chris Date's temporal model, which advocates a chronon
> model for temporal data and some weird extensions to the relational model
> for them. Even before Rick Snodgrass did his work in the field, Zeno's
> paradoxes and Einstein's physics showed that time is a continuum and not a
> set of discrete points, so time is made up of durations that cannot be
> defined as countable sets of points.

        Being constantly in the move in the last year I haven't delved deep into this, as it seems the only good explanation of their model is in the book. So I can't evaluate your claims yet.

> 5) If anyone mentions my name to him, he will simply insult me without
> giving them a reason. Example: on dbdebunk.com,one of his replies to an
> email that mentioned my name as a source for SQL info was simply "Stay
> away from Celko!" and nothing else.

        You represent SQL... he does not need to explain more.

        But yes, he's rude.

> At least, I itemize differences in the SQL-92 (me), Chris Date and Ted
> Codd versions of the RM and the various extensions to each one.

        SQL ain't relational, c'mon. By implying so you give Fabian all the reason he could ever need.

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