- From: Seaborne, Andy <andy.seaborne@hp.com>
- Date: Thu, 2 Jun 2005 11:17:01 +0100
- To: "Steve Harris" <S.W.Harris@ecs.soton.ac.uk>, "RDF Data Access Working Group" <public-rdf-dawg@w3.org>
-------- Original Message --------
> From: Steve Harris <>
> Date: 2 June 2005 09:45
>
> On Thu, Jun 02, 2005 at 01:48:58AM -0400, Eric Prud'hommeaux wrote:
> > Recording Yoshio and my whiteboard discussion here:
> >
> > Given this data:
> > <c>:
> > <A> knows <B>
> >
> > <d>:
> > <B> mbox <mailto:b>
> >
> > It seems the following 4 expressions are all equivilent:
> >
> > (1) (Named Graphs (arbitrary pre-existing data)):
> > FROM <c> <d>
> > WHERE {
> > GRAPH ?g { ?who knows ?whom } .
> > GRAPH ?g { ?whom mbox ?mbox } .
> > FILTER ?g = <c> || ?g = <d>
> >
> > (2) (Source (arbitrary pre-existing data)):
> > FROM <c> <d>
> > WHERE {
> > SOURCE ?g { ?who knows ?whom } .
> > SOURCE ?g { ?whom mbox ?mbox } .
> > FILTER ?g = <c> || ?g = <d>
> >
> > (3) (No Default Graph):
> > FROM <c> <d>
> > WHERE {
> > ?who knows ?whom .
> > ?whom mbox ?mbox } }
> >
> > (?) (Source + CLEAR (arbitrary pre-existing data)): CLEAR
> > FROM <c> <d>
> > WHERE {
> > ?who knows ?whom .
> > ?whom mbox ?mbox } }
>
> I dont believe so, wouldn't
>
> FROM <c> <d>
> WHERE {
> ?who knows ?whom .
> ?whom mbox ?mbox }
>
> Be equivalent to
>
> FROM <c> <d>
> WHERE {
> SOURCE ?g1 { ?who knows ?whom } .
> SOURCE ?g2 { ?whom mbox ?mbox } .
> FILTER ?g1 = <c> || ?g1 = <d> &&
> ?g2 = <c> || ?g2 = <d> }
>
> - Steve
And, if I understand this correctly, a step further,
FROM NAMED <c>
FROM NAMED <d>
WHERE {
GRAPH ?g { ?who knows ?whom } .
GRAPH ?g { ?whom mbox ?mbox } .
FILTER ?g = <c> || ?g = <d>
}
??
Andy
Received on Thursday, 2 June 2005 10:17:10 UTC