Re: PROV-AQ: How to indicate SPARQL endpoint for provenance (ISSUE 609)

This seems like the only option, in particular, if we ensure that that the
template that needs to be returned is ligh-weight....

regards
Paul


On Wed, Jan 2, 2013 at 3:49 PM, Graham Klyne <Graham.Klyne@zoo.ox.ac.uk>wrote:

> Tim,
> Paul,
>
> Following an extended discussion with Erik Wilde, I'm now persuaded that
> an new
> link relation is not the best way to go for SPARQL endpoints.
>
> I the absence of a clear alternative proposal, I propose to stick with RDF
> (in
> any of its syntaxes) for the service description.
>
> I do think we want an easy way to distinguish different service
> implementations
> in an RDF service description, and my preference for this would be the
> rdf:type
> of the described service resource.
>
> Thus, if we have a provenance service that supports both the templated and
> SPARQL interfaces, I would anticipate a service description along these
> lines:
>
> [[
> <#template> a prov:ProvenanceService ;
>      prov:provenanceUriTemplate "http://www.example.net/prov?target={+uri}
> "
>      .
>
> <#sparql> a sd:Service ;
>      # (description per http://www.w3.org/TR/sparql11-service-description/
> )
>      sd:endpoint <http://www.example.net/sparql/> ;
>      sd:supportedLanguage sd:SPARQL11Query ;
>      sd:resultFormat <http://www.w3.org/ns/formats/RDF_XML> ,
>                      <http://www.w3.org/ns/formats/Turtle> ,
>                      <http://www.w3.org/ns/formats/SPARQL_Results_XML> ,
>                      <http://www.w3.org/ns/formats/SPARQL_Results_JSON> ,
>                      <http://www.w3.org/ns/formats/SPARQL_Results_CSV> ,
>                      <http://www.w3.org/ns/formats/SPARQL_Results_TSV>
>      .
> ]]
>
> I think it's easy to see how this can generalize to accommodate alternative
> services if such are introduced later.
>
> In practice, I anticipate that different service URIs (indicated by
> multiple
> provenance service link headers) would each implement a single access
> mechanism,
> so the multiple options within a single service description as shown above
> are
> not a requirement.
>
> Tim: you indicated previously that prov:ProvenanceService should apply to
> *all*
> forms of provenance service.  I haven't proposed that above, but it would
> be
> possible to have this as a generic class for all provenance services, with
> the
> above example then becoming, say:
>
> [[
> <#template> a prov:TemplatedService, prov:ProvenanceService ;
>      prov:provenanceUriTemplate "http://www.example.net/prov?target={+uri}
> "
>      .
>
> <#sparql> a sd:Service, prov:ProvenanceService ;
>      # (description per http://www.w3.org/TR/sparql11-service-description/
> )
>      sd:endpoint <http://www.example.net/sparql/> ;
>      sd:supportedLanguage sd:SPARQL11Query ;
>      sd:resultFormat <http://www.w3.org/ns/formats/RDF_XML> ,
>                      <http://www.w3.org/ns/formats/Turtle> ,
>                      <http://www.w3.org/ns/formats/SPARQL_Results_XML> ,
>                      <http://www.w3.org/ns/formats/SPARQL_Results_JSON> ,
>                      <http://www.w3.org/ns/formats/SPARQL_Results_CSV> ,
>                      <http://www.w3.org/ns/formats/SPARQL_Results_TSV>
>      .
> ]]
>
> If you're OK with this, I'll plan to update PROV-AQ accordingly (but I
> can't
> guarantee to have it done until after next week, as I'm travelling to a
> meeting
> then.)
>
> #g
> --
>
> On 29/11/2012 18:53, Timothy Lebo wrote:
> > all,
> >
> > On Nov 29, 2012, at 1:36 PM, Graham Klyne <Graham.Klyne@zoo.ox.ac.uk>
> wrote:
> >
> >> We decided to drop the merely advisory material about how to use
> SPARQL, and leave that to the FAQ.  But discovery of a SPARQL endpoint got
> forgotten in the change (I think it was never really specified previously).
> >>
> >> I think the cleanest solution would to to introduce another link
> relation
> >
> > 1)
> >
> > I'm not fond of another link relation just to point to one specific
> service technology.
> >
> > To handle "discovery of SPARQL endpoints" I think we should instead
> combine:
> >      A) GET on service gives RDF description.  (as already stated)
> >      B) http://www.w3.org/TR/sparql11-service-description/
> >
> > to return:
> >
> > <service-URI> a prov:ProvenanceService, sd:Service ;
> > additional vocabulary from B should be used further describe the service.
> > The fact that <service-URI> is a sd:Service indicates that it is a
> SPARQL endpoint.
> >
> >
> > 2)
> >
> > The following citation seems to be inconsistent.
> >
> > [SPARQL-HTTP]
> > Chimezie Ogbuji. SPARQL 1.1 Service Description. 2011, Work in progress.
> URL: http://www.w3.org/TR/sparql11-http-rdf-update/
> >
> > 3)
> >
> > In
> http://dvcs.w3.org/hg/prov/raw-file/tip/paq/prov-aq.html#provenance-service-description
> > I do not think the prov:provenanceUriTemplate property should be so
> prominent.
> >
> > The first example:
> >
> >    <service-URI> a prov:ProvenanceService ;
> >      prov:provenanceUriTemplate "service-URI?target={+uri}" .
> > should be trimmed to:
> >
> >    <service-URI> a prov:ProvenanceService ;
> >
> > with prov:provenanceUriTemplate being described as an OPTIONAL
> description in subsequent discussion (as it stands now, it appears to be
> required).
> > This, too, is an assumption on how a service could be accessed.
> >
> > -Tim
> >
> >
> >
> >
> >
> >
> >> for a SPARQL query endpoint (but to not get into details of how to
> formulate the queries, other than to say that they are presented via SPARQL
> HTTP protocol, and executed over provenance formulated as RDF according to
> PROV-O).
> >>
> >> I'll raise an issue for this.
> >>
> >> #g
> >> --
> >>
> >> Tracker, this is issue 609
> >>
> >>
> >> On 29/11/2012 15:59, Paul Groth wrote:
> >>> It's a good question. I wonder if we can somehow role this into
> >>> provenance-service url?
> >>>
> >>> Paul
> >>>
> >>>
> >>> On Thu, Nov 29, 2012 at 4:30 PM, Cresswell, Stephen <
> stephen.cresswell@tso.co.uk
> >>> <mailto:stephen.cresswell@tso.co.uk>> wrote:
> >>>
> >>>     Hi,____
> >>>
> >>>     __ __
> >>>
> >>>     It still seems to me appropriate for PROV-AQ to include some
> method by which
> >>>     publishers of a resource can indicate a SPARQL endpoint for
> provenance
> >>>     queries.____
> >>>
> >>>     There was some discussion on this about a year ago, but it got
> stuck on
> >>>     unresolved questions about named graphs, and doesn’t seem to have
> made it
> >>>     into the document.____
> >>>
> >>>     __ __
> >>>
> >>>     Has there been a decision not to accommodate this, or is it still a
> >>>     possibility?____
> >>>
> >>>     __ __
> >>>
> >>>
> http://lists.w3.org/Archives/Public/public-prov-wg/2011Dec/0067.html____
> >>>
> >>>
> http://lists.w3.org/Archives/Public/public-prov-wg/2011Dec/0040.html____
> >>>
> >>>
> http://lists.w3.org/Archives/Public/public-prov-wg/2011Dec/0039.html____
> >>>
> >>>     __ __
> >>>
> >>>     Stephen Cresswell____
> >>>
> >>>     __ __
> >>>
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> >>>
> >>>
> >>> --
> >>> --
> >>> Dr. Paul Groth (p.t.groth@vu.nl <mailto:p.t.groth@vu.nl>)
> >>> http://www.few.vu.nl/~pgroth/ <http://www.few.vu.nl/%7Epgroth/>
> >>> Assistant Professor
> >>> - Knowledge Representation & Reasoning Group |
> >>>    Artificial Intelligence Section | Department of Computer Science
> >>> - The Network Institute
> >>> VU University Amsterdam
> >>
> >>
> >
> >
>



-- 
--
Dr. Paul Groth (p.t.groth@vu.nl)
http://www.few.vu.nl/~pgroth/
Assistant Professor
- Knowledge Representation & Reasoning Group |
  Artificial Intelligence Section | Department of Computer Science
- The Network Institute
VU University Amsterdam

Received on Wednesday, 2 January 2013 15:05:03 UTC