- From: Gregory Williams <greg@evilfunhouse.com>
- Date: Wed, 29 Oct 2014 09:25:02 -0700
- To: Ruben Verborgh <ruben.verborgh@ugent.be>
- Cc: Eric Prud'hommeaux <eric@w3.org>, semantic-web <semantic-web@w3.org>
On Oct 29, 2014, at 6:58 AM, Ruben Verborgh <ruben.verborgh@ugent.be> wrote: >> The above doc describes paging over "blank-node-free" triples. Is that to simplify ordering? > > The main reason is that blank nodes cannot be identified across different requests. > For instance, if I request the triple pattern fragment for ?x rdf:type foaf:Person > and the results contain _:b0 rdf;:ype foaf:Person, > how can I ask for more data about this person? > I cannot ask for _:b0 ?p ?o, > because the local identifier _:b0 was only valid in the context of the first response. > > We solve this by translating all blank nodes to IRIs, following [1]. Ruben, I’m interested to see that you’re skolemizing blank nodes in the DBPedia Fragments data as I think this addresses some obvious challenges to using Triple Pattern Fragments with arbitrary RDF. However, I don’t see any mention of doing this in the Triple Pattern Fragments spec. Would you consider adding this as a recommendation (“SHOULD”) to the spec, with a description of the problem it solves? thanks, .greg
Received on Wednesday, 29 October 2014 16:25:29 UTC