Hi Kunal, We support Transitive Closures via SPARQL extensions pragmas. We allow you to identify the property/predicate of the transitive closure and the depth.
See: input:grab-seealso / input:grab-follow-predicate, input:grab-limit, input:grab-depth at: http://docs.openlinksw.com/virtuoso/rdfiridereferencing.html Best Regards, Hugh Williams Professional Services OpenLink Software Web: http://www.openlinksw.com Universal Data Access & Data Integration Technology Providers On 12/02/2008 03:07, "Kunal Patel" <kunaled...@yahoo.com> wrote: > Hi Ivan, > > Just to make sure that I understood you correctly, currently in Virtuoso > there is no way to define an inference rule that can be used for doing say > transitive closure. > > Also what does Virtuoso do with the OWL/RDFS constructs that it doesn't > support. For e.g. if I load an OWL file containing a property P that is > transitive, will Virtuoso simply ignore that fact when it computes the query > results on property P. > > Thanks, > Kunal > > Ivan Mikhailov <imikhai...@openlinksw.com> wrote: >> Kunal, >> >> We do not have "universal" inference rules, we have only partial support >> for same-as and sub-properties. We're focusing on scalability and using >> relational data with all native indexes; this implies that inference is >> possible only in DATALOG style. Obviously, optimizing DATALOG compiler >> is a big thing that should be made after everything else. So we will >> complete SPARQL BI extensions first, updateable RDF Views after that; >> only after these major extensions we may think about future DATALOG >> implementation. >> >> I'd say that the main purpose of the seealso and subtype inference for >> us was to pass LUBM benchmark. Seriously speaking, this is the biggest >> subset of real inference functionality that is cheap to implement, and >> even very weak subset is better than nothing. >> >> When we decided what to implement we had no idea of what's commonly used >> and what's not, but we looked at the LUBM and assumed that if a feature >> is placed in benchmark by more experienced users then it worth enough. >> >> In common case, custom inference rules are to materialized RDF views as >> SQL procedure views are to auxiliary tables filled in by triggers. We do >> not have SPARQL procedure views (no SPARQL views at all) so the only >> thing we can suggest if our inference is not sufficient is to write >> application logic to fill in auxiliary graphs. >> >> Best Regards, >> Ivan Mikhailov, >> OpenLink Software >> >> P.S. Sorry for late reply, initially this was sent to a wrong list of >> recipients. >> >> > > > > > Never miss a thing. Make Yahoo your homepage. > <http://us.rd.yahoo.com/evt=51438/*http://www.yahoo.com/r/hs> > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Microsoft > Defy all challenges. Microsoft(R) Visual Studio 2008. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > > _______________________________________________ > Virtuoso-users mailing list > Virtuoso-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/virtuoso-users > > >
