Re: [xml-dev] Caught napping!

[Joe English <jenglish@flightlab.com>]

PaulT wrote:

> Yes, we know that RDB does not solve the problem.
> Honest.
> But I'd put it slightly different.
> "Almost all current SQL servers - kinda suck".
> I can elaborate why, but that's not my point.

Can *anyone* elaborate on this?  Fabian Pascal
goes on at length about how SQL is a poor shadow
of the true Relational Model, but I can't seem to
find any specific criticisms on his web site.
(Presumably he goes into detail in one of his
books, but I'm reluctant to shell out the cash.)

SQL has its obvious deficiencies, but based on
my (admittedly limited) understanding of the
relational model I don't see any gross divergences
from mathematical theory.  (Well maybe one: it
works at a different level of the Boom hierarchy,
returning a Bag instead of a Set unless you use
SELECT DISTINCT).

[ earlier ]
> 1. XML has no reasonable model behind it.
> ( where it is? where is the math, 'mapped'  into
> some real stuff ( like it is with SQL and/or regexprs),
> the stuff that I can run on my computer? )

There's plenty of theory that's applicable to XML, you just have
to look outside the W3C to find most of it.  RELAX/TREX/RELAX-NG
are based on very elegant mathematics; there's Dan Suciu
and Mary Fernandez' work on semistructured data; there's
all the work Anne Brueggemann-Klein and Derick Wood have done
on DTDs, typesetting, and context matching; et cetera,
et cetera.  Even within the W3C, some of the top researchers
in functional programming and type systems are working on
the formal model for XQuery, and pretty much everything
that James Clark has worked on has a solid (if not explicit)
mathematical underpinning.


--Joe English

  jenglish@flightlab.com