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

From: Kingsley Idehen <kidehen@openlinksw.com>
Date: Wed, 14 May 2008 14:59:29 -0400
Message-ID: <482B3691.4030104@openlinksw.com>
To: Kendall Grant Clark <kendall@clarkparsia.com>
CC: Michael F Uschold <uschold@gmail.com>, Tim Berners-Lee <timbl@w3.org>, Sören Auer <auer@informatik.uni-leipzig.de>, Chris Bizer <chris@bizer.de>, Frank van Harmelen <frank.van.harmelen@cs.vu.nl>, Semantic Web Interest Group <semantic-web@w3.org>, "Fabian M. Suchanek" <f.m.suchanek@gmail.com>, Tim Berners-Lee <timbl@csail.mit.edu>, jim hendler <hendler@cs.rpi.edu>, Mark Greaves <markg@vulcan.com>, "georgi.kobilarov" <georgi.kobilarov@gmx.de>, Jens Lehmann <lehmann@informatik.uni-leipzig.de>, Richard Cyganiak <richard@cyganiak.de>, Frederick Giasson <fred@fgiasson.com>, Michael Bergman <mike@mkbergman.com>, Conor Shankey <cshankey@reinvent.com>, Kira Oujonkova <koujonkova@reinvent.com>, Aldo Gangemi <aldo.gangemi@istc.cnr.it>, Ivan Mikhailov <iv@openlinksw.com>, Orri Erling <oerling@openlinksw.com>, Alan Ruttenberg <alanruttenberg@gmail.com>

Kendall Grant Clark wrote:
> 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

Owlgres is a PostgreSQL application. Why the DBMS specificity?

Virtuoso is an Object-Relational DBMS like PostgreSQL and it supports 

What does PosgreSQL offer that you may have assumed is/was missing from 
Virtuoso when developing this application?

Note: Some additional context to digest prior to responding:

1. OpenLink Software built the first ODBC Driver for PosgreSQL (at a 
time when it was Postgre95)
2. We continue to develop and support PostgreSQL ODBC Drivers
3. PostgreSQL was an option during the exploratory days preceding my 
decision to use Kubl to create Virtuoso [1]
4. Virtuoso is available in Open Source form just like PosgtreSQL

I've also added, Orri Erling (Program Manager Virtuoso), Ivan Mikhailov 
(Lead Developer of Virtuoso's Quad Store functionality realm), and Alan 
Rutternberg to this thread (Alan is interested in Owlgres and Virtuoso 


1. http://virtuoso.openlinksw.com/wiki/main/Main/VOSHistory



Kingsley Idehen	      Weblog: http://www.openlinksw.com/blog/~kidehen
President & CEO 
OpenLink Software     Web: http://www.openlinksw.com
Received on Wednesday, 14 May 2008 19:00:20 UTC

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