Datasets are covered very nicely in the RDF core recommendations: https://www.w3.org/TR/rdf11-concepts/#section-dataset
--- A. Soroka The University of Virginia Library > On Apr 2, 2017, at 5:38 AM, Dave Reynolds <dave.e.reyno...@gmail.com> wrote: > > On 02/04/17 10:25, Laura Morales wrote: >>>> - no inference over the whole graph, only inference on a single graph >>> >>> No inference support over the whole *Dataset*. >> >> "whole graph" I mean 2 or more graphs loaded into the server, that together >> make a larger graph. Isn't this the same thing as "dataset"? Or am I missing >> something? >> > > A Dataset is a collection of graph comprising one default graph and zero or > more named graphs. > > The default graph in a dataset may be completely distinct from the named > graphs or may contain some precomputed combination of them or (e.g. with TDB > union default) you can arrange for the default graph to give the appearance > of being the union of all the triples in all the named graphs. These are all > choices, the notion of a dataset doesn't enforce any particular > implementation for the default graph > > My point is that Jena's rule-based inference engines don't know anything > about datasets, just about graphs. > > However, you can point an inference engine at any graph in TDB including the > union graph (either by using union default and pointing to the default graph > or by pointing to the pseudo named graph urn:x-arq:UnionGraph). Then you are > indeed performing inference over the union of the data it's just that the > inference engine doesn't know that or care. > > Dave >
