- From: Dave Reynolds <der@hplb.hpl.hp.com>
- Date: Wed, 03 May 2006 18:05:57 +0100
- To: Michael Kifer <kifer@cs.sunysb.edu>
- CC: public-rif-wg@w3.org
Michael Kifer wrote:
>> Alex Kozlenkov wrote:
>>
>>> I am not sending a message against OWL or RDF. I am simply asking
>>> whether _querying_ RDF and OWL in rule antecedents is enough or not for
>>> RIF at this time.
>> As I've already said in my response to the proposal, external-query-only
>> is not sufficient from my point of view. I need to be able to express at
>> least deduction rules over RDF and an external query approach doesn't
>> facilitate that. I would prefer a tighter embedding of RDF into RIF
>> (e.g. either a three place predicate or the ability to interpret any
>> atoms over binary relations as RDF triple patterns).
>
> I think people have different ideas regarding what an "external query"
> means - hence all this discussion (probably).
>
> For me, an external query means a predicate that represents some particular
> aspects of an external system. This can have (and should have) several forms.
>
> For instance, if I just want to query RDF triples, OWL classes or roles,
> then I should just be able to use 3-place/2-place/1-place predicates for
> those things. E.g., motherOf(?X,?Y) to query the mother-of role in OWL.
>
> You can write your RDF or whatever rules over these predicates, and I think
> this satisfies your requirements.
Agreed. Although in the case of RDF deduction rules there is not
necessarily any "external system" involved.
> But I also may want to send a SPARQL query to an RDF base or to send a DL
> expression to an OWL system.
> For that we should have something like
>
> rdf_query('sparql stuff', list-of-variables-to-be-bound)
> owl_query('some DL expr',...)
Absolutely, I'm in no way denying the value of also being able to issue
a SPARQL query including/especially one to an external data source. This
is a good facility to have.
Dave
Received on Wednesday, 3 May 2006 17:06:21 UTC