W3C home > Mailing lists > Public > public-rdf-dawg@w3.org > October to December 2004

Re: tests and inference? (and UNSAID)

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>
Message-ID: <20041222111004.GB8105@login.ecs.soton.ac.uk>

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 GMT

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