Re: Agenda Topic / Issue: Clarify the meaning of "ignore" with respect to attributes that have no legal value

Mark Birbeck <mark.birbeck@webbackplane.com> wrote:
> The final piece of the jigsaw is to bring back in the earlier point,
> i.e., that the spec allows us to create a triple from 'foobar'
> provided that we don't put it into the default graph. In this case my
> parser might place the 'unknown' triple into a separate graph:
> 
>   Default graph:
>     _:a foaf:name "Mark" .
> 
>   Graph A:
>     <#shane> ex:blah _:a .
> 
> Now, as you can see, even though it's in a separate graph, I could
> still run a SPARQL query over *both* graphs to yield the following
> triples:
> 
>   <#shane> ex:blah _:a .
>   _:a foaf:name "Mark" .
> 
> And since the parsing algorithm caused us to generate a bnode despite
> not understanding 'ex:blah', then the triples in the two separate
> graphs are 'aligned'.

My understanding from reading "Named Graphs, Provenance and Trust" [1],
is that blank nodes can't be shared between graphs, making this type of
query impossible. Graph A has to be a superset of the default graph for
this to work.

[1] http://www2005.org/cdrom/docs/p613.pdf

Regards,

Tore Eriksson

_______________________________________________________________
<> dc:creator [
   foaf:name "Tore Eriksson",
             "トーレ　エリクソン"@jp;
   foaf:mbox_sha1sum "2bd9291b301f112775e118f96eb63314594b1a86";
   foaf:workplaceHomepage <http://www.taisho.co.jp/> ].

Received on Friday, 11 September 2009 07:38:02 UTC