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http-rdf-update and the default graph

From: Andy Seaborne <andy.seaborne@epimorphics.com>
Date: Wed, 29 Sep 2010 22:55:52 +0100
Message-ID: <4CA3B5E8.5090505@epimorphics.com>
To: SPARQL Working Group <public-rdf-dawg@w3.org>
In implementing http-rdf-update, I need to also address the default 
graph of a graph store, for POST and GET.

I have been using the absence of ?graph= to mean the default graph

http://host/dataset?graph=http://example/graph1
http://host/dataset

but this is wrong because to look at it another way, the URI before the 
query string is the name of the graph store, not the default graph.  GET 
http://host/dataset might usefully return N-Quads.

Is this the right way to view it or should I be using some thing like:

http://host/dataset?default

At one level, this is an extension to http-rdf-update because 
http-rdf-update does not cover addressing the default graph of a graph 
store, but at the same time, it would be good for implementations to do 
the same thing.

"Network-manipulable Graph Store" excludes the default graph but I don't 
see an rationale for this.  If it had been just a collection of graphs, 
not a graph store, then the absence of an un-named one is explicable, 
but the document directly discusses graph stores and whether a URI 
identifies the underlying network-manipulable Graph Store.

A simple additional naming form would expose the default graph.


Related to this:

Section 8:

[[
It is RECOMMENDED that the web address of SPARQL 1.1/Service 
Descriptions be specified.
]]

This confused me.  Earlier, the text used the URI as the graph store, 
not the service (description).  We seem to have update and/or query 
service at the same place as the graph store.  This would be OK, as 
services are split by HTTP query string, but not if the graph store is 
GETtable and there is a service description to return.

For http-rdf-update, I'd suggest it's the graph store (RDF dataset) that 
is on the web.  The service model is more appropriate for SPARQL Update 
language and query.


Minor editorial:

5.4 HTTP GET
mentions graph store without the network-manipulable qualification.

	Andy
Received on Wednesday, 29 September 2010 21:57:01 GMT

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