- From: Patrick Stickler <patrick.stickler@nokia.com>
- Date: Tue, 13 Apr 2004 11:05:52 +0300
- To: "ext Howard Katz" <howardk@fatdog.com>
- Cc: "Dirk Colaert" <Dirk.Colaert@quadrat.be>, "Rob Shearer" <Rob.Shearer@networkinference.com>, <public-rdf-dawg@w3.org>, "Eric Prud'hommeaux" <eric@w3.org>
On Apr 08, 2004, at 17:14, ext Howard Katz wrote: > > > >>> (2) If queries are represented in XML they can be treated as data >>> and you can run XQueries over a collection of XQueries. >> >> That's interesting. A Query expressed in RDF could be treated as RDF. >> It >> would be easy to do queries about queries. That's an argument for >> using RDF >> (or a subset, or a convertible format). >> >> All we have to do know is find a use case justifying this >> requirement... :-) > > It does sound wonderful, doesn't it? I too would like to know what you > would > want to query in a query. Examples anyone ... ? > If one kept a record of submitted queries in a special knowledge base, one could submit queries against that knowledge base to generate various statistics about queries having particular characteristics; e.g. * terms from particular vocabularies * use of typed literals * use of language qualified literals * 'select' versus description results etc. Each statistic target would be defined by a query, and the number of target queries matched would provide the score. That's just one example. Patrick >> >> Or do we have a solution without a problem? >> >> Dirk >> >> -----Original Message----- >> From: Howard Katz [mailto:howardk@fatdog.com] >> Sent: mercredi 7 avril 2004 7:08 >> To: Eric Prud'hommeaux >> Cc: Rob Shearer; public-rdf-dawg@w3.org >> Subject: RE: Requirement: queries written as RDF >> >> >> I got several responses back from members of the Query wg on the >> XQueryX >> question. I particularly liked this one. I don't know if it'll shed >> any >> light on our own issues, but it's delightfully clear and succinct. The >> author prefers to remain anonymous. >> >> In response to a question on why XQueryX: >> >>> (1) An XML-based syntax was considered easier for machines to >>> generate and exchange than a human-oriented syntax that would >>> require some sophisticated parsing. >>> (2) If queries are represented in XML they can be treated as data >>> and you can run XQueries over a collection of XQueries. >>> (3) Since XML is known to be an answer to all questions, it must be >>> an answer to the question "What would be a good format for expressing >>> queries over XML data"? >> >> In response to a question on the technical difficulties that >> arose once the >> requirement was formulated: >> >>> Once the requirement for an XML query syntax was adopted, >>> arguments immediately broke out over the level of detail at >> which a query >>> should be broken down into XML elements. The working group >> finally settled >>> on two separate approaches that represent extreme points on the >> spectrum: >>> (a) The whole query is wrapped in a <query> element, and otherwise >> unchanged. >>> This approach obviously does not take the XML syntax requirement very >> seriously. >>> (b) The query is parsed, and each and every node in the parse tree >> (including individual >>> operators, function calls, steps in path expressions, etc.) is >> represented >> by its own >>> element, thus making the query incredibly verbose. This format is >> obviously useless to humans. >> >>> At various times and places, people have attempted to define some >> intermediate point >>> between these two extremes. These attempts have always ended in >> rancor and >> controversy. >> >> Finally, in a follow-up clarification: >> >>> I believe that the editor of the XQueryX specification is currently >> pursuing both approaches >>> (a) minimal expansion and (b) maximal expansion. Both will be >>> defined as >> valid forms of >>> XQueryX. >> >> Just to close on a personal note, I've always felt that XML is >> the answer to >> all questions. I'm now coming to feel increasingly that RDF is >> even more so! >> >> Howard >> >>>> On Sun, Apr 04, 2004 at 09:23:14AM -0700, Howard Katz wrote: >>> >>> [snip ...] >>> >>>>> I certainly agree with the sentiments of the second, "human >> readable" >>>>> requirement. Interestingly enough, the third, "XML" requirement >>>> has been the >>>>> one that's caused the group the most difficulty to my >>>> knowledge, and at the >>>>> moment conformance with this requirement has been downgraded to >>>> optional. I >>>>> don't know what the major issues have been, but it might be >>>> interesting to >>>>> know, if only for the sake of curiosity. >>>> >>>> Can we go beyond the meta-lesson of "that may be hard. it's been >>>> hard >>>> in XQuery" to some of the particular problems that requirement >>>> caused >>>> the XQuery WG? Also, was this requirement born of some compelling >>>> use >>>> cases, or a general notion that it's good practice to express >>>> anything >>>> in XML? >>> >>> I wasn't trying to impart a particular lesson. My intention, not >>> knowing >>> what DAWG members know or don't know about it, was simply to >>> provide data on >>> the experience of the Query wg in the event that might prove >> useful to the >>> group. In response to your questions, I've asked several >> members of the wg >>> about their XQueryX experience. If they see fit to pass that on >>> to me, I'll >>> be happy to share it with the group. >>> >>> Howard >>> > > -- Patrick Stickler Nokia, Finland patrick.stickler@nokia.com
Received on Tuesday, 13 April 2004 04:25:48 UTC