Thinking Clearly - Latest Comments in Owlgres: A Scalable OWL Reasoner

Re: Owlgres: A Scalable OWL Reasoner

Oleg Bartunov — Mon, 01 Sep 2008 08:50:12 -0000

Markus,

I'm PostgreSQL developer and would like to work on effective
RDF storage in PostgreSQL in the framework of our astronomical
project "Astronet" (www.astronet.ru). We developed and maintain
GiST and GIN indexing framework as well as text search and other
PostgreSQL extensions. I'm not an expert in ontology technologies
yet and have no practical experience. If you have any specific postgreSQL problems or ideas how to improve performance of semantic queries, don't hesitate to communicate.

Best regards,
Oleg

Re: Owlgres: A Scalable OWL Reasoner

Kendall — Tue, 17 Jun 2008 17:51:32 -0000

Olivier,

I can't speak for the other projects, but Owlgres isn't Postgres-specific or even tied to Postgres. We developed it with Postgres in mind, but we don't any Postgres internals tweaking. Owlgres exists purely at the JDBC level, except for database-specific setup code.

So we could easily make Owlgres work for Oracle or DB2, and probably will do so at some point.

To get the *most* performance, one might tweak some DB internals (which is one reason we *prefer* Postgres), but so far that's not been necessary.

Re: Owlgres: A Scalable OWL Reasoner

lolive — Mon, 16 Jun 2008 17:28:49 -0000

IBM is working on a DLP (and now DL) engine on top of DB2.
there is an attempt from the EPFL to add such support to Oracle. OwlGres is targetted at Postgres.

Definitely there is something to investigate, it seems :)

From a developper point of view, I have a concern.
Is it possible to abstract such a technology from the RDBMS?
So we are not tied to a given "vendor".

Or does it require fine tuning of the database internals?

Re: Owlgres: A Scalable OWL Reasoner

Kendall — Wed, 26 Mar 2008 16:24:24 -0000

John,

There will be a first public release soonish; we'll be giving demos at OWLED next week, and I think some Ordnance Survey folks will be there. After that, we'll make a public release.

Re: Owlgres: A Scalable OWL Reasoner

JohnGoodwin — Wed, 26 Mar 2008 11:50:04 -0000

Is there a demo version we can download and experiment with?

Re: Owlgres: A Scalable OWL Reasoner

Mike Smith — Mon, 24 Mar 2008 12:39:41 -0000

Readers should note that LUBM, as generally used, is not expressible in DL-Lite because it uses transitive properties and because qualified existentials are used in the left side of subsumption relations. The results presented here are with a modified version that reduces the expressivity.