2011/8/20 Eric Scott <[email protected]>: > I'm working on a project that explores integrating a fairly large pre- (or > at least extra-) rdf ontology into RDF, the better to link to other > ontologies. > > Code has been written which translates the ontology written into proprietary > format into rdf triples. It is stored in a TDB database, and amounts to > about 11 million statements. At this point almost all URIs are outside the > standard RDF namespaces. It has it's own equivalent of subClassOf, for > example. We can query the triplestore effectively as-is. > > So in order to integrate this ontology with linked RDF data, it'd be nice to > use things like owl:equivalentProperty to express equivalence between say, > my:parentClass and rdfs:subClassOf. > > The first problem I'm encountering is that when I create a TDB model from > our 11M triples, then create an inference model integrated with an owl > reasoner, the system takes an intractably long time to load - even before I > declare any relationships of any kind. > > Is this expected behavior? Is there a workaround? Would it be better to > rewrite the Proprietary->RDF translator to substitute say rdfs:subClassOf > for my:parentClass? >
I'm not sure whether this comment is relevant, but it looks to me like yes, renaming from an arbitrary property to rdfs:subClassOf should help; I can imagine a few reasoners: a) having trouble understanding that these property assertions are not ABox axioms but TBox axioms (a bunch of tableaux optimizations cannot be applied safely when ABoxes exist, I believe, so reasoners would switch them off) b) having to reason about the equivalent properties as well: wherever an existing hierarchy is already in the ontology, your properties will be asserted as well; any domain/range would come into play as well, complicating things while the intention does not appear to be to change the interpretation c) reasoners may consider the subjects and objects of these properties as both classes (because they appear in triples with rdfs:subClassOf) and individuals (because they appear in triples with some other property); many of the reasoners I've had experience with start creaking at the joints with large number of individuals. Take this with a pinch of salt :-) renaming might pose other problems of which I'm not aware. HTH, I. > Any help appreciated. > > Regards, >
