- From: Orri Erling <erling@xs4all.nl>
- Date: Sun, 15 Mar 2009 23:08:03 +0100
- To: "'Steve Harris'" <steve.harris@garlik.com>, "'SPARQL Working Group'" <public-rdf-dawg@w3.org>
-----Original Message----- From: public-rdf-dawg-request@w3.org [mailto:public-rdf-dawg-request@w3.org] On Behalf Of Steve Harris Sent: Saturday, March 14, 2009 12:46 AM To: SPARQL Working Group Subject: Re: Next telecon features & beyond On 13 Mar 2009, at 19:36, Lee Feigenbaum wrote: > Alexandre Passant wrote: >> Without any pathLength filtering, the query is simply a property >> path query as proposed in [3], but that way of using a variable >> (rather than including the regexp directly as in ":foo rdf:type/ >> rdfs:subClassOf* :bar") allows imho more extensibility, especially >> for that length feature. > > Right, but [3] doesn't include variables in the path position. > Putting my implementer's hat on, I think that allowing path > variables is significantly more challenging to implement, so much so > that I'd prefer to consider the two cases separately. I agree. - Steve Hi Virtuoso has a transitive feature that can deal with path ;lengths and returning data associated with steps on the path. Combining this with an aggregate like SQL's XMLAGG and grouping would allow returning a path as a single variable binding, now to an XML fragment describing the path. This features is a bit complex and I do not consider it probable that the working group could arrive to consensus regarding it, so standardizing this is not our top agenda. But since the matter was brought up, we would refer you to our documentation on this. Ivan, please send the SQL and SPARQL transitivity sections to the list as attachments or put them on the Virtuoso blog so they can be read. Since this is Virtuoso 6 material, it I not on the main docs site. Orri -- Steve Harris Garlik Limited, 2 Sheen Road, Richmond, TW9 1AE, UK +44(0)20 8973 2465 http://www.garlik.com/ Registered in England and Wales 535 7233 VAT # 849 0517 11 Registered office: Thames House, Portsmouth Road, Esher, Surrey, KT10 9AD -- No virus found in this incoming message. Checked by AVG. Version: 7.5.557 / Virus Database: 270.11.13/2001 - Release Date: 3/14/2009 6:54 AM
Received on Sunday, 15 March 2009 22:09:45 UTC