Re: AW: (SeWeb) KAON - KArlsruhe ONtology and Semantic Web Infrastructure

Alexander Maedche wrote:
> With respect to existing RDF parsers we were 
> confronted with serious performance problems.
> Thus, we implemented a new one being compliant
> to the W3C specification.

As the developer of the Jena RDF parser (ARP) I read this paragraph with 
interest.

I am aware that my work has some performance issues; however I have 
never had a user request to work on the performance. Our analysis has 
been that a typical RDF application spends a relatively small percentage 
of time in parsing. Thus we have put our development effort in an 
emphasis on correct behaviour, tracking the RDFCore WG recommendations 
and passing all the new RDF Core parser test cases.

There are at least two major optimizations missing from the Jena parser:
- in lax mode, switiching off the extensive error checking rather than 
merely switching off error messages
- using the Xerces pull parsing interface to allow single threaded 
operation (while retaining the architectural advantages of the coparsing 
design of the Jena parser)

I would welcome changes to the Jena code to include these improvements 
from anyone who is interested in faster, correct RDF parsing. I look 
forward to greater cooperation between the community of open source 
semantic web developers.

At the moment the Jena team would welcome ideas about open source (BSD 
license compatible) reasoners that can cope with large subsets of DAML 
or OWL.

Jeremy

Received on Thursday, 10 October 2002 12:59:54 UTC