Hello Alexandre,
> But I still don't understand the meaning of "the dataset includes an
> empty graph for the default graph".
>
> What does that mean for you ?
The default graph is always part of context of SPARQL processor. That is
union of all graphs specified in FROM, (or something
implementation-specific if no FROM clauses present in the query, say,
union of all available graphs). When default graph is empty then a
triple pattern outside any GRAPH {...} group patterns will produce no
bindings. The current bug is that the default graph is non-empty now so
a triple pattern can access everything. I'll fix this soon.
Best Regards,
Ivan Mikhailov
OpenLink Software
http://virtuoso.openlinksw.com
>
