ISWC 2014

October 28th, 2014 6:44 PM

Last week I attended ISWC 2014 in Riva del Garda and had a very nice time.

Riva del Garda

I presented a paper at the Developers Workshop about designing the new PerlRDF and SPARQLKit systems using trait-based programming. Covering more PerlRDF work, Kjetil presented his work on RDF::LinkedData.

Answering SPARQL Queries over Databases under OWL 2 QL Entailment Regime by Kontchakov, et al. caught my attention during the main conference. The authors show a technique to map query answering under OWL QL entailment to pure SPARQL 1.1 queries under simple entailment, allowing OWL QL reasoning to be used with SPARQL 1.1 systems that do not otherwise support OWL. An important challenge highlighted by the work (and echoed by the audience after the presentation) was the limited performance of existing property path implementations. It seems as if there might be a subset of SPARQL 1.1 property paths (e.g. with limited nesting of path operators) that could be implemented more efficiently while providing enough expressivity to allow things like OWL reasoning.

There seemed to be a lot of interest in more flexible solutions to SPARQL query answering. Ruben’s Linked Data Fragments work addresses one part of this issue (though I remain somewhat skeptical about it as a general-purpose solution). That work was received very well at the conference, winning the Best Demo award. In conversations I had, there was also a lot of interest in the development of SPARQL systems that could handle capacity and scalability issues more gracefully (being smart enough to use appropriate HTTP error codes when a query cannot be answered due to system load or the complexity of the query, allowing a fallback to linked data fragments, for example).