W3C home > Mailing lists > Public > public-rdf-wg@w3.org > April 2012

Re: the term "named graphs"

From: Andy Seaborne <andy.seaborne@epimorphics.com>
Date: Fri, 27 Apr 2012 19:27:18 +0100
Message-ID: <4F9AE506.6010302@epimorphics.com>
To: public-rdf-wg@w3.org


On 27/04/12 19:01, Sandro Hawke wrote:
> On Fri, 2012-04-27 at 10:45 -0700, Jeremy Carroll wrote:
>> On 4/27/2012 1:44 AM, Antoine Zimmermann wrote:
>>> Remember that "named graph" is normative as it's part of a normative
>>> section of the SPARQL recommendation.
>>
>> I just looked this up, and the definition seems to be in section 8
>> http://www.w3.org/TR/2008/REC-rdf-sparql-query-20080115/#rdfDataset
>> "An RDF Dataset comprises one graph, the default graph, which does not
>> have a name, and zero or more named graphs, where each named graph is
>> identified by an IRI."
>>
>> This wording seems to me to suggest that G is a named graph if and only
>> if there is a pair
>>
>> (u, G)
>>
>> in the dataset.
>
> Thanks for looking that up.  I'm fine with that meaning for the term.
>
> Being pedantic, and using my terms from 6.3, the named graph is the RDF
> Graph comprising the RDF Triples known to be contained by the graph
> resource which has the given name.   But I don't think boiling that down
> to "named graph" is too misleading.
>
>       -- Sandro
>

Strictly, the definition is:

http://www.w3.org/TR/2008/REC-rdf-sparql-query-20080115/#sparqlDataset

and definition is a named graph is the pair.

A red thing has an attribute that it is read.
A named thing has an attribute that it is named.

So it could be a set of { name , triples} , of { name , set of triples } 
or with named attribute (name=u, graph=G) but we happen to write the 
name aspect and graph value aspect as a pair (u,G)

G can have a life of it's own - and a different name elsewhere.

(u1, G) and (u2, G) are different named graphs.

	Andy
Received on Friday, 27 April 2012 18:27:48 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 22:02:04 UTC