- From: Seaborne, Andy <andy.seaborne@hp.com>
- Date: Wed, 22 Dec 2004 17:18:45 +0000
- To: Dan Connolly <connolly@w3.org>
- Cc: RDF Data Access Working Group <public-rdf-dawg@w3.org>
Dan Connolly wrote: > I think I have mentioned this in IRC now and then, but I don't > think I have sent mail about it. Please specify the language > without reference to implementations. > > That is, take out stuff like: > > "If a query processor encounters a function that it does not provide, > the query is not executed and an error is returned." > http://www.w3.org/2001/sw/DataAccess/rq23/#TestingExtensions > $Revision: 1.160 $ of $Date: 2004/12/17 18:16:17 $ Section 11.3: "Section status: placeholder text - not integrated" > > Stuff like "note that the query processor does not have to have any > understanding of the values in the space of the datatype" is perhaps > OK as informal explanation. > > "RDF systems are not required to implement the entailements expressed by > these rules, but may choose to do so" looks like it refers to some > standardized notion of "RDF system"; I'm not aware of one. Please > ground it with a link if there is one. And what does "may choose > to do so" mean? Does it impact definitions such as Query Results? > If so, the language isn't well-defined; its definition depends > on implementations. > > (hmm... where's the term that's like Query Results but factors > in constraints, optionals, unsaid, and all that?) > > I prefer to get rid of the whole section > 3.3 Implementation Requirements. Likely to go anyway but something that discusses the relationship with the XSD datatype hierarchy is needed. Suggestions? > If the WG really wants to get > into software conformance clauses, (a) it will have a considerable > impact on our schedule, which is already at risk; I'm not sure > we can do that without extending the duration of the WG, > which requires negotiating with various parties outside the WG, > and (b) the language needs to be specified without reference > to implementations anyway and (c) we'll need clear > definitions for the product classes > (some advice is available in section > 2.2 What needs to conform of the QA spec guidelines > http://www.w3.org/TR/2004/WD-qaframe-spec-20041122/#what-conform) > > > This looks like a pretty clear problem: > > "The following are equivalent for a query processor that handles > preciates for mathmatical expressions:" > > It seems to me that datatype entailments are no different from > RDFS entailments; some systems pre-compute them and use > the result as the input graph when evaluating queries. That > doesn't change how queries work. > > The query written... > > WHERE ( ?x dc:title ?title ) > ( ?x ns:price ?price ) > ( ?price op:numeric-less-than 30 ) > > will only match if the input graph includes a triple ala > > <#x> op:numeric-less-than 30. > > I suggest rewriting "3.4 Constraints and Predicates" to be > include discussion of RDFS, and making it clear that it's > informative, i.e. not part of the definition of the query > language. 3.4 will go - it does not work as it puts literals as subjects into the graph. suggestions for content welcome. > > I was hoping we could leave the input graph that a service > chooses fairly opaque for v1, but we don't seem to be > able to avoid discussing service descriptions or complex > FROM clauses or something. Hm... I think there's another > issue brewing... > >
Received on Wednesday, 22 December 2004 17:19:17 UTC