On 24/08/12 11:25, Andy Seaborne wrote:
On 23/08/12 22:51, Simon Helsen wrote:
Currently, TDB/ARQ does not do this, but only picks matches
from graphUri1. Given that unionDefaultGraph=true should merge all named
graphs into the default graph, this is surprising. To elaborate a bit, we
found that the following query
SELECT ?o
FROM NAMED <graphUri2>
WHERE { ?s <somePredicate> ?o }
Bug.
Or maybe not. The code specifically tests for the case of
unionDefaultGraph and not specificed graphs on the dynamic datasets
description.
The code is in:
com.hp.hpl.jena.sparql.coreDynamicDatasets
It moved from TDB only a few days ago but no functionality changed.
It is still the case that if you did specific the default graph at all,
then that applies, regardless of union-setting.
And of course the real (storage) default graph and the union graph both
have URI names.
Andy
If you specify the dataset description, you are giving a complete
description. There is an empty default graph in that description.
does pick results from graphUri2 (when run with unionDefaultGraph==true).
Also, when we execute the following query:
SELECT ?o
FROM <graphUri1>
FROM NAMED <graphUri2>
WHERE { graph ?g { ?s <somePredicate> ?o } }
then tdb seems to pick results from graphUri2 which is as expected.
We were thinking that explicit FROM/FROM NAMED clauses simply ignores the
unionDefaultGraph=true switch which could then explain the behavior of
the
first query above, but it doesn't explain the one of the second query.
Feedback on this is welcome.
thanks,
Simon
