- From: Steve Harris <S.W.Harris@ecs.soton.ac.uk>
- Date: Thu, 2 Jun 2005 09:44:39 +0100
- To: RDF Data Access Working Group <public-rdf-dawg@w3.org>
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
Received on Thursday, 2 June 2005 08:44:43 UTC