Hi Nina, Egon, All,
   It seems that OntModel and "Default" Model implementations are
equivalent in terms of performance. We measured the time needed to
download and parse datasets into a Jena Model Object. The results are
summarized in the last paragraph of the attached document.

Best Regards,
Pantelis

On Thu, 2010-10-07 at 04:24 +0300, chung wrote:

> Hi Nina,
> 
> On Wed, 2010-10-06 at 18:23 +0300, Nina Jeliazkova wrote:
> 
> > Hi Pantelis,
> > 
> > Just to add - if I understood right, it might require some work to parse non
> > - OntModel into ToxOtis internal objects, but what I would be interested is
> > the time to parse the incoming stream into Jena model only, ignoring further
> > transformations for the time being.
> 
> 
> We've put this in high priority so that in case there's a significant
> difference between OntModel and other Model implementations, we'll
> refactor a bit the source code. So we'll have the related results by
> tomorrow...
> 
> Pantelis
> 
> > 
> > Do you think this kind of measurement is feasible?
> > Nina
> > 
> > On Wed, Oct 6, 2010 at 6:17 PM, Nina Jeliazkova
> > <jeliazkova.nina at gmail.com>wrote:
> > 
> > > Hi Pantelis,
> > >
> > > There is no problem of parsing OWL-DL with Jena models (recall OWL-DL is a
> > > valid RDF) , different than OntModel.
> > >
> > > You will only loose some convenient methods and classes in Jena, but you
> > > can still check if a class has certain rdf:type or certain properties.  I
> > > agree the client code might became less elegant , but performance gain may
> > > worth it.
> > >
> > >
> > > On Wed, Oct 6, 2010 at 6:08 PM, chung <chvng at mail.ntua.gr> wrote:
> > >
> > >> Hi Nina, Egon,
> > >>   That would be an interesting experiment in general but there are some
> > >> technical problems related to ToxOtis and to the current format of our
> > >> RDF documents. First of all, a common RDF specification has been chosen,
> > >> that is OWL-DL and we have lots of times striven to stick to it. ToxOtis
> > >> produces OWL-DL compliant RDF representations for every OpenTox entity
> > >> (methods asIndividual(OntModel):Individual and asOntModel():OntModel ).
> > >> OntModel and OntClass have been chosen as the prime Jena objects to work
> > >> with in ToxOtis and in YAQP, our web application also. Apart from the
> > >> fact that it would be hard to change that, I also reckon we shouldn't
> > >> for various reasons I'll try to summarize.
> > >>
> > >
> > >
> > >   OntModel is an interface that offers lots of functionalities such as
> > >> creation of Annotation, Datatype and Object Properties that are missing
> > >> from the interface Model where one can just use m.createProperty(String)
> > >> to create an untyped property. Additionally, OntModel is tightly
> > >> connected to OntClass, an interface used to describe the ontological
> > >> classes to which instances are binded. So if we need to produce OWL-DL
> > >> compliant representations we either need an implementation of OntModel
> > >> and OntClass provided by Jena or one of ours. My opinion is that the
> > >> adoption of OWL-DL against OWL-Full or OWL-Lite does not increase
> > >> significantly the size of the representation. What is more, OWL-DL
> > >> guarantees computability and decidability and does not oblige users to
> > >> use some inference engine that imposes overhead so it would be better to
> > >> cling to it both for the server and from the client side.
> > >>   As you already know, using OntModel we have performed measurements to
> > >> compare between different specifications and it was shown that OWL-DL
> > >> performs better for parsing documents compared to OWL and OWL-Lite. What
> > >> might be of interest is to reveal the impact of the cache size (for in
> > >> memory triple storage) on the performance of RDF parse/serialization
> > >> procedure and on the allocation of resources.
> > >>
> > >> Best Regards,
> > >> Pantelis
> > >>
> > >> On Wed, 2010-10-06 at 15:12 +0200, Egon Willighagen wrote:
> > >>
> > >> > Pantelis,
> > >> >
> > >> > On Wed, Oct 6, 2010 at 2:58 PM, Nina Jeliazkova
> > >> > <jeliazkova.nina at gmail.com> wrote:
> > >> > >> Would it be hard for you to switch to "plain" RDF (i.e.  omit all
> > >> > >> RDF:type statements) and compare computation times with OWL
> > >> > >> representations.
> > >> > >
> > >> > > From dataset service point of view it is practically impossible,
> > >> without
> > >> > > breaking everything,  but form client point of view one can try using
> > >> Jena
> > >> > > models, different than OntModel.
> > >> >
> > >> > what happens if you use either of these:
> > >> >
> > >> > ModelFactory.createDefaultModel()
> > >> > ModelFactory.createNonreifyingModel()
> > >> >
> > >> > ?
> > >>
> > >>
> > >> If you think this is necessary, we can set up an experiment without
> > >> ToxOtis...
> > >>
> > >
> > >
> > > Yes, please (unless it is a month work...)
> > >
> > > Best regards,
> > > Nina
> > >
> > >
> > >
> > >
> > >>
> > >> >
> > >> > Egon
> > >> >
> > >>
> > >>
> > >> _______________________________________________
> > >> Development mailing list
> > >> Development at opentox.org
> > >> http://www.opentox.org/mailman/listinfo/development
> > >>
> > >
> > >
> > >
> > _______________________________________________
> > Development mailing list
> > Development at opentox.org
> > http://www.opentox.org/mailman/listinfo/development
> > 
> 
> 
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> 


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