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Re: considering new issues: rdfSemantics, owlIntegration, owlDisjunction

From: Dan Connolly <connolly@w3.org>
Date: Fri, 09 Sep 2005 18:17:43 -0500
To: RDF Data Access Working Group <public-rdf-dawg@w3.org>
Message-Id: <1126307863.4430.380.camel@dirk>

On Thu, 2005-09-08 at 08:18 -0500, Dan Connolly wrote:
> Given recent discussion and comments, I'm inclined to add
> three issues to our issues list...
>   http://www.w3.org/2001/sw/DataAccess/issues
> rdfSemantics -- should queries of equivalent graphs
> give the same answers? Any practical advice about queries
> over infinite graph such as all the RDF axiomatic triples?

> owlDisjunction -- the worker example evidently doesn't work
> well with SPARQL as of the 21 July 2005 LCWD. Are there
> mature designs that work better? At a minimum, we should
> be explicit that we don't handle this.

Those two are now open.


> owlIntegration -- some explicit explanation of how OWL integrates
> with SPARQL seems worthwhile.

I don't know if that's a separate issue. We'll see how the
more concrete ones go.

> Is that too many or too few issues to cover recent discussions?

I see a request to re-consider SOURCE/GRAPH and UNSAID/OPTIONAL/BOUND
in Enrico's comments...

"The construct GRAPH, combined with FROM clauses, allows to bind
variables/restrict graphs the triples came from. The main problem with
this feature is that the RDF Dataset deļ¬nition ... does not have a
corresponding semantics in the RDF model theory.  ...
We reckon that the possibility of referring to graph names enables some
interesting features of the query language; however, we believe that
this should be excluded from cSPARQL."
 -- http://www.inf.unibz.it/krdb/w3c/sparql-notes-fub.html

But I think the WG already considered that argument in Hensinki...

"... DanC argued against taking us out of the scope of positive
conjunctive queries against RDF graphs. ..."
 -- http://www.w3.org/2001/sw/DataAccess/ftf4.html

It's possible that our discussion of rdfSemantics will result in
adopting a requirement for soundness/completeness semantics, in which
case it will be necessary to reconsider the SOURCE and UNSAID issues.
But for now, I'm leaving them closed.

Dan Connolly, W3C http://www.w3.org/People/Connolly/
D3C2 887B 0F92 6005 C541  0875 0F91 96DE 6E52 C29E
Received on Friday, 9 September 2005 23:17:52 UTC

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