Re: newbie question about sparql and 200

On Aug 14, 2008, at 9:24 AM, Dan Connolly wrote:

> On Thu, 2008-08-14 at 00:27 -0400, Alan Ruttenberg wrote:
>> On Aug 14, 2008, at 12:11 AM, Dan Connolly wrote:
>>
>>> On Wed, 2008-08-13 at 19:17 -0400, Alan Ruttenberg wrote:
>>>> Does this mean that the IRI following the GRAPH keyword also
>>>> denotes a
>>>> document? Or that the same iri can denotes both a graph and its
>>>> serialization?
>>>
>>> No. It just means what it says.
>>
>> If I understood what it says, I wouldn't have asked for
>> clarification. Care to be a little more educational? Does
>> "represents" mean awww:represents, the relation between what comes
>> back over the wire when you do an http GET on a URI and what the URI
>> denotes?
>
> Yes, I read it that way.

Then the note seems confusing. A graph is an information resource,  
plain and simple. Information resources, in WEBARCH sense,  unless  
they are fixedresources,  in the are available in a number of  
formats. When you make a HTTP request to get one, possibly with  
content negotiation.

Why is the note necessary? In fact it seems backwards:

>>>>> "The FROM NAMED syntax suggests that the IRI identifies the
>>>>> corresponding graph, but the relationship between an IRI and a  
>>>>> graph
>>>>> in an RDF dataset is indirect. The IRI identifies a resource,  
>>>>> and the
>>>>> resource is represented by a graph (or, more precisely: by a
>>>>> document that serializes a graph). For further details see  
>>>>> [WEBARCH]."


That is, the IRI identifies the graph, and the representation is a  
serialization of that graph. How is it different than asking for any  
document, and getting back either html, or rtf, or whatever?

-Alan


>
>
>> -Alan
>>
>>
>>>
>>>> -Alan
>>>>
>>>> On Aug 13, 2008, at 4:39 PM, Dan Connolly <connolly@w3.org> wrote:
>>>>
>>>>>
>>>>> On Wed, 2008-08-13 at 14:16 -0400, Jonathan Rees wrote:
>>>>>> If I say, in SPARQL:
>>>>>>
>>>>>> select * from <http://example.com/graph1> { ... }
>>>>>>
>>>>>> then by my reading of the SPARQL rec (http://www.w3.org/TR/rdf-
>>>>>> sparql-query/
>>>>>> ), http://example.com/graph1 is supposed to name a (named)
>>>>>> graph. But
>>>>>> some SPARQL servers take the URI in a FROM or GRAPH clause and
>>>>>> use it
>>>>>> with HTTP to fetch an RDF/XML or Turtle document, from which
>>>>>> triples
>>>>>> are obtained. By the httpRange-14 resolution, the 200 response
>>>>>> means
>>>>>> that the URI names an information resource.
>>>>>
>>>>> yes...
>>>>>
>>>>>> Therefore, at least some RDF graphs (or named graphs) are
>>>>>> information
>>>>>> resources, right?
>>>>>
>>>>> Strictly speaking, not quite; the SPARQL
>>>>> spec includes this clarification:
>>>>>
>>>>> "The FROM NAMED syntax suggests that the IRI identifies the
>>>>> corresponding graph, but the relationship between an IRI and a  
>>>>> graph
>>>>> in
>>>>> an RDF dataset is indirect. The IRI identifies a resource, and the
>>>>> resource is represented by a graph (or, more precisely: by a
>>>>> document
>>>>> that serializes a graph). For further details see [WEBARCH]."
>>>>>
>>>>>>
>>>>>> I'm sure this has been discussed before...
>>>>>>
>>>>>> Jonathan
>>>
>>> -- 
>>> Dan Connolly, W3C http://www.w3.org/People/Connolly/
>>> gpg D3C2 887B 0F92 6005 C541  0875 0F91 96DE 6E52 C29E
>>>
>>>
> -- 
> Dan Connolly, W3C http://www.w3.org/People/Connolly/
> gpg D3C2 887B 0F92 6005 C541  0875 0F91 96DE 6E52 C29E
>

Received on Thursday, 14 August 2008 17:10:41 UTC