- From: Seaborne, Andy <andy.seaborne@hp.com>
- Date: Mon, 28 Jun 2004 22:18:18 +0100
- To: "'Howard Katz'" <howardk@fatdog.com>, <public-rdf-dawg@w3.org>
Howard, I have got through the XsRQL proposal - nicely written document and I have a good sense of what XsRQL is and does. I particularly liked the style except the yellow (!) ... A few "straightforward" questions: 1/ Is the output always syntactic? Some of the examples are explicitly creating strings in the query itself. In RDQL, the output is not defined: indeed, in Jena, the output is a Java structure with the real RDF Java objects so you can switch between query and other APIs. The formatted output shown in the tutorial is based on feeding queries to a general result as formatter as accessed through the command line wrapper. The decision on formatting is not part of the query process but part of the formatting process. 2/ XsRQL is strong on the construction side of results: how do you see this working with rules? 3/ The data model has subjects, predicates and objects and the syntax uses cues to indicate what is a predicate using @. How do I write a query that does (?x ?x anything) Which would match the well known "rdf:type rdf:type rdf:Property." RDF works on URIrefs rather than types so I wonder if this makes a difference or not. [More common would be queries that work on properties and then access any domain and range constraints use a predicted URI is a property and as a subject.] 4/ (checking question) In { $libby, @newFoaf:Name, $libby/@foaf:name/* } does the generation create many triples, one for each match of $libby/@foaf:name/* or a triple with a sequence for the object value? I presume it's the former. 5/ Could you add collections to the types? This seems quite tricky to deal with in any triple oriented RDF query language. Andy -------- Original Message -------- > From: public-rdf-dawg-request@w3.org <> > Date: 27 June 2004 21:40 > > I've finished my XSRQL proposal, which can be found at > http://www.fatdog.com/xsrql.html. You'll notice I've shortened the > acronym slightly: XSRQL stands for XQuery-style RDF Query Language. I > hope this latest addition to the query-language canon isn't > considered overly XS-ive (groan). > > I'm slightly embarrassed; I've gone totally overboard on > this. (If you encounter graffiti in public lavatories > reading, "Stop me before I write again!", it was probably > me.) In any event, those who don't have the time or the > desire to plow through the proposal in its entirety can > probably get a fairly quick idea of what the language is > about by reading the introduction [1] and then skipping to > the section on the path language [2] . You might also find > the Examples section [3], which looks at several examples of > code in both RDQL and XSRQL, of interest. Once you've > recovered from that, you can go back and read the rest at your leisure. > > I'd be honoured if somebody would volunteer to pick this up > for evaluation before the agenda deadline (July 7?). I'm > around through this coming Tuesday evening, so if anybody has > any questions, either get a hold of me before then or after > I'm back from vacation on the 6th. > > Ta, > Howard > > [1] http://www.fatdog.com/xsrql.html#Introduction > > [2] http://www.fatdog.com/xsrql.html#Path%20language > > [3] http://www.fatdog.com/xsrql.html#Examples
Received on Monday, 28 June 2004 17:18:42 UTC