- From: Steve Harris <steve.harris@garlik.com>
- Date: Wed, 4 Apr 2012 11:18:22 +0100
- To: Andy Seaborne <andy.seaborne@epimorphics.com>
- Cc: public-rdf-wg@w3.org
On 2012-04-04, at 08:25, Andy Seaborne wrote:
>
> On 03/04/12 01:27, Sandro Hawke wrote:
>>>> There's some misunderstanding here, yes. Maybe you can talk through
>>>> > > some particular thing you imagine doing, involving merging and TriG, and
>>>> > > I'll be able to pick it up. From what you've written, I'm confused.
>>>> > >
>>>> > > Maybe I can clarifying by translating this TriG document:
>>>> > >
>>>> > > <u1> {<a> <b> <c> }
>>>> > >
>>>> > > into this English declaration:
>>>> > >
>>>> > > The URI 'u1' denotes something, and that thing has exactly one
>>>> > > associated RDF Graph. That associated RDF graph consists of
>>>> > > one RDF triple, which we can write in turtle as "<a> <b> <c>".
>>> >
>>> >
>>> > Clearer, but not what I would have expected.
>>> >
>>> > Why "exactly one associated RDF Graph"?
>> My intuition is that there are important thing you can't do if you allow
>> more than one graph to be associated with the named object, but I
>> haven't really explored that because SPARQL datasets clearly allow only
>> one GRAPH for a given name, so I figured we'd stick with that. That's
>> why I said hasGraph was a functional property.
>
> A query executes at some (idealized) point in time, and a query closes the world to execute (or they'd never complete!). An RDF Dataset is the local concept for the data being queried - there's no statement about anything outside the local context made, or needed for SPARQL.
+1
This is an important distinction.
- Steve
--
Steve Harris, CTO
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Received on Wednesday, 4 April 2012 10:19:05 UTC