SPARQL 1.1 federation extension

Dear all,

my name is Carlos Buil-Aranda and I'm a PhD student at UPM in Madrid. I'm
currently working in a SPARQL federation system, using Jena and a
distributed query processing system called OGSA-DAI. As a comment to the
post from Lee Feigenbaum (
http://www.thefigtrees.net/lee/blog/2010/07/early_sparql_reviews.html)
regarding federation,

   - Should support for SERVICE be mandatory in SPARQL 1.1 Query
   implementations?
   - Should support for BINDINGS be mandatory in SPARQL 1.1 Query
   implementations?


Just to say that I'm working in one of the implementations, which is quite
advanced. I published as a technical report a description of my previous
work: http://oa.upm.es/3302/ which I'm adapting to the SPARQL 1.1 federation
extension.

Regarding the if BINDINGS and SERVICE should be mandatory I think that none
of them should be mandatory in SPARQL 1.1 (I'm assuming that mandatory means
that SPARQL 1.1 implementations should implement these two functinalities).
I think that not all people would want to query a set of SPARQL endpoints
instead of just one. But, as user, I'd like to have the option of joining
the results from a query to other different resources. The decision should
be up to the user.

I have one question. Looking at the mailing list I've seen the status of the
SPARQL 1.1 implementation status:
http://lists.w3.org/Archives/Public/public-rdf-dawg/2010AprJun/0422.html
 and http://wiki.github.com/kasei/perlrdf/sparql-11-status in which it says
that the federation extension is 100% implemented. Do you know which system
is implementing it? can you point me to some description of it?

since UPM is also member of W3C I will try to participate more in the group,
contributing as needed.

Regards :)

Carlos