- From: Andy Seaborne <andy.seaborne@talis.com>
- Date: Mon, 17 May 2010 23:05:28 +0100
- To: Lee Feigenbaum <lee@thefigtrees.net>
- CC: Olivier Corby <Olivier.Corby@sophia.inria.fr>, SPARQL Working Group <public-rdf-dawg@w3.org>
On 17/05/2010 7:14 PM, Lee Feigenbaum wrote: > On 5/17/2010 8:03 AM, Olivier Corby wrote: >> > PROPOSED: Close ISSUE-8 with the consensus that subqueries share the >> same RDF >> > dataset as their parent query, and that FROM and FROM NAMED clauses >> are not >> > permitted in subqueries. >> >> As I said in a previous post, I think there is an interaction between >> graph and subquery patterns. Does the graph pattern apply to subquery: >> >> >> graph ?g { >> {select * where { ... }} >> } >> >> >> I think this is not obvious because we can consider that the subquery >> creates a fresh new evaluation environment without graph ?g as current >> graph. >> >> This interpretation is based on this case: >> >> graph ?g1 { >> graph ?g2 { } >> } >> >> In this example, graph ?g2 creates a new evaluation environment in which >> graph ?g2 overloads/hides graph ?g1. We could have the same behavior >> with subquery. >> >> I think that the recommendation should explicit the behavior of graph >> pattern vs subquery. > > I agree. Do you have a preference for the behavior of this construct? I suggest that the active graph is carried into a subquery. This makes: WHERE { { something } { SELECT * { ... } } } ==> WHERE { GRAPH <g> { { something } { SELECT * { ... } } } } retarget the whole of the pattern to match against <g> { SELECT * { ... } } is then a no-op (adds no project or other solution modifier) in terms of algebra. Andy > > Lee > >> > > > Please consider the environment before printing this email. > > Find out more about Talis at http://www.talis.com/ > shared innovation™ > > Any views or personal opinions expressed within this email may not be > those of Talis Information Ltd or its employees. The content of this > email message and any files that may be attached are confidential, and > for the usage of the intended recipient only. If you are not the > intended recipient, then please return this message to the sender and > delete it. Any use of this e-mail by an unauthorised recipient is > prohibited. > > Talis Information Ltd is a member of the Talis Group of companies and is > registered in England No 3638278 with its registered office at Knights > Court, Solihull Parkway, Birmingham Business Park, B37 7YB.
Received on Monday, 17 May 2010 22:11:08 UTC