Excerpts from Michael F Uschold's message of Wed May 14 12:06:36 -0400 2008: > > **JimHendler *summarized things this way: "So what you are really saying is > scaling is a technology/research challenge now that there's much more out > there. We need to go beyond just triple stores and get some fast inferencing > at Web scales. Makes sense to me." Absolutely. But it's gotten harder lately to find support for that research, IMO. We've been working on this for OWL2 DL-Lite and for EL++, two tractable profiles of OWL (as Jim well knows! :>). The next version of Pellet [1] will include an EL-optimized reasoner (though not over secondary storage), and we just released Owlgres 0.1 [2], which is an OWL2 DL-Lite reasoner for Postgresql for large data sets. > *MikeUschold *noted that the computational issue of owl:sameAs proliferation > is a major problem, even if noone is going to load all the semantic web data > into a single store. For today's triple stores that do limited inference, > owl:sameAs "has a significant run time" according both to common sense as > well as the developers of OpenLink's Virtuoso triple > store<http://docs.openlinksw.com/virtuoso/rdfsparqlrule.html#rdfsparqlruleintro> > . > They say it can easily double query > times<http://www.openlinksw.com/weblog/oerling/?id=1347>. You don't have to do it at query time. Owlgres does owl:sameAs processing at load time and so the *query time* cost is negligible. The usual caveats about tradeoffs and use cases apply, of course. Cheers, Kendall Clark 1 http://pellet.owldl.com/ 2 http://pellet.owldl.com/owlgresReceived on Wednesday, 14 May 2008 18:26:45 GMT
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