- From: Steve Harris <S.W.Harris@ecs.soton.ac.uk>
- Date: Wed, 22 Dec 2004 11:10:04 +0000
- To: RDF Data Access Working Group <public-rdf-dawg@w3.org>
On Wed, Dec 22, 2004 at 10:32:11 +0000, Andy Seaborne wrote:
> >>FROM could make sense - the server offers a numer of graphs and the
> >>URI in teh FROM must choose one of them. If it names some graph the
> >>server is not publishing, then the query generates an error. FROM
> >>isn't a requirements to load any graph (I worry about the security
> >>issues of that). A server may require that there is only one URI in
> >>the FROM clause - i.e. no arbitrary RDF merge of graphs. It is just a
> >>request for something that the server does not offer.
> >
> >
> >Agreed. I think we should allow a server to refuse to answer a query if
> >it names FROM a graph that the server cannot (prefers not to) access,
> >and we should allow the query to provide a variable in the FROM position
> >which gets bound to the name of the source as part of the answer, so
> >that a query can say, in effect: answer this from any source you choose,
> >but tell me what the source was.
>
> Woudl using "SOURCE ?src { ... query pattern ... }" achived this effect if
> the query is over the collection of named graphs?
I would hope so, named grpahs or not.
> >Query-answering servers should be
> >required to provide a binding to any such variable, even if it is a
> >'trivial' one which simply identifies the server itself (which means,
> >roughly: I am the source, and that's all you are going to get out of me
> >on that topic.)
>
> Interesting - this is saying the default graph has a URI.
>
> I wonder how that interacts with the protocol.
I interpreted that part of the protocol as refering to the KB level, ie.
the level at which triples dont interact. Though I contradicted that in a
previous mail. Must learn to stop sending mail pre-coffee.
- Steve
Received on Wednesday, 22 December 2004 11:10:08 UTC