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
