Re: Managing Co-reference (Was: A Semantic Elephant?)

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/owlgres

Received on Wednesday, 14 May 2008 18:26:45 UTC