- From: Eric Prud'hommeaux <eric@w3.org>
- Date: Thu, 1 Apr 2004 23:27:07 -0500
- To: Rob Shearer <Rob.Shearer@networkinference.com>
- Cc: public-rdf-dawg@w3.org
On Thu, Apr 01, 2004 at 12:30:46PM -0800, Rob Shearer wrote: > > I'd like some clarification of just what we're trying to get at from > this requirement. > > Are we saying that we want queries to fit into the RDF/XML syntax? I'd > like clarification on just what users and use cases benefit from such a > syntax. My experience is that forcing RDF/XML syntax just makes it damn > near impossible for humans to compose a document without lots of help > from tools. examples of queries in RDFXML: DQL: http://www.w3.org/2001/11/13-RDF-Query-Rules/#DQL and other XML: XDD: http://www.w3.org/2001/11/13-RDF-Query-Rules/#XDD RuleML: http://www.w3.org/2001/11/13-RDF-Query-Rules/#RuleML QEL: http://www.w3.org/2001/11/13-RDF-Query-Rules/#QEL > If queries are being generated automatically, most software > systems are pretty agnostic just what their output syntax is, so I don't > see RDF representations as helping them much, either. Such RDFXML query-generating tools would require a human-composable query language to allow people to easily express their queries as strings (unless we think everyone composing queries will use GUIs and expert systems). > Are we saying that we want queries to fit the RDF data model? If so, I > don't think it's met trivially, since just about anything can be > translated into RDF--that's the whole point of RDF. Agreed. Once we know how to express a variable in the RDF model, I think the query expression will fall out. > Or are we saying that given some chunk of RDF, there should be some > sensible query connotation that it invokes? Is this a roundabout way of > getting back to entailment as an independent query--i.e. here's some > RDF; does it necessarily follow from the source I'm querying? I think we can express last option as a degernate form of a query with a premise; the premise is written in RDFXML and the query is "is this true?" If we treat it this way, we can also express premises for queries in a more general case, ala "If prefectures and departements are the same as states, what are the addresses of all the members of the DAWG?" assume (jp:prefecture owl:sameAs fr:department && fr:department owl:sameAs us:staet) ask (?who wg:memberOf w3c:DAWG && ?who ad:workAddr ?addr && ?addr ad:streetNo ?number && ?addr ad:streetName ?street && ?addr ad:city ?city && ?addr ad:state ?state) ?addr ad:country ?country) collect (?number ?street ?city ?state ?country) Or maybe even negative premises: "If KendallC did NOT foaf:know DanC, would he still transitively know PatHayes?" -- -eric office: +81.466.49.1170 W3C, Keio Research Institute at SFC, Shonan Fujisawa Campus, Keio University, 5322 Endo, Fujisawa, Kanagawa 252-8520 JAPAN +1.617.258.5741 NE43-344, MIT, Cambridge, MA 02144 USA cell: +1.857.222.5741 (does not work in Asia) (eric@w3.org) Feel free to forward this message to any list for any purpose other than email address distribution.
Received on Thursday, 1 April 2004 23:27:58 UTC