Path: newssvr20.news.prodigy.com!newsmst01.news.prodigy.com!prodigy.com!prodigy.com!news.glorb.com!postnews1.google.com!not-for-mail From: andrewst@onetel.net.uk (Tony) Newsgroups: comp.databases.theory Subject: Re: Xquery might have some things right Date: 3 Mar 2004 13:35:47 -0800 Organization: http://groups.google.com Lines: 47 Message-ID: References: NNTP-Posting-Host: 80.3.32.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Trace: posting.google.com 1078349755 17411 127.0.0.1 (3 Mar 2004 21:35:55 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Wed, 3 Mar 2004 21:35:55 +0000 (UTC) Xref: newssvr20.news.prodigy.com comp.databases.theory:24383 "Dawn M. Wolthuis" wrote in message news:... > "Tony" wrote in message > news:c0e3f26e.0403030402.2510647b@posting.google.com... > > "Dawn M. Wolthuis" wrote in message > news:... > > > Are there XQuery fans on this list? --dawn > > > > Not many, but it does not surprise me that you are one of them. > > You didn't read very well. I have more often critcized XQuery than > applauded it and it is only in the last week that I decided to learn it > better so that any criticisms had more knowledge at the base. It is then > that I found a few gems and thought I'd pass them along. You are correct: I have missed the posts where you criticise XQuery, sorry. > > Look: > > a procedural way of querying a hierarchic database. What a great leap > > forward! > > Ah, blinded by glasses you have been wearing for, perhaps, too long? You > should rather think of it as a means of navigating di-graphs of data. And that would be better because...? I don't want to "navigate" through the data, since I know a better way: define the sets of data I want, and leave the DBMS to "navigate" however it decides is optimal. Why should *I* have to do all the work? > When both the data model and the data operators are represented as functions > (which, by definition are relations), there are some gains we can make. > Think of all of the work to be done in terms of > > function(input)=output > > If we represent all input and output as functions (such as > ObjectFunction(referenceID) = objectdata), then there is only one type of > data (for storage purposes, for example) -- FUNCTIONS! That's it -- you > apply one function to another until you get the function to store or output > in some other way. Sounds like LISP (which I quite liked in a quirky sort of way at one time). However, relational databases only have one type of data too - relations! And SQL databases (not really the same thing, as I'm sure you are only too aware by now) have only tables - if you ignore some of the egregious OO "extensions".