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Re: fast inferencing with jena and "?"

From: Dave Reynolds <der@hplb.hpl.hp.com>
Date: Mon, 21 Mar 2005 11:16:54 +0000
Message-ID: <423EAD26.7000701@hplb.hpl.hp.com>
To: Leo Sauermann <leo@gnowsis.com>
CC: semantic-web@w3.org

Hi Leo,

> The problem with Jena is: the Model RDFS_MEM_TRANS_INF is too slow to do
> simple inference (and it was the fastest we found in jena)

Which version of Jena? There was a bug fix affecting TRANS between 2.1 and 
2.2beta1 and a performance problem fixed between 2.2beta1 and 2.2beta2.

> It has 200ms performance of matching two small rdf instance models
> against a RDF/S ontology model (180 classes). 

What do you mean by "matching" a model against an RDFS model?

If you can show us what you are doing (ideally a self-contained code 
example) then we might be able to advise on optimizations. Though code 
exchange is probably better done over on jena-dev or off list.

> We did everything we could to make it faster, including prefetching all
> classes, properties, trying out different Jena inferencers, etc.

If you prefetched all classes and properties then there is presumably no 
inference left. If the performance wasn't good enough in that set up then 
you don't need faster inference you need a faster algorithm or reduced API 
overheads. That would make it even more interesting to see exactly what you 
are doing to figure where the performance problem is.

Received on Monday, 21 March 2005 11:17:37 UTC

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