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Re: Comment re SPARQL 1.1 Service Description

From: Leigh Dodds <leigh.dodds@talis.com>
Date: Mon, 7 Jun 2010 11:30:37 +0100
Message-ID: <AANLkTimLousAXdbXiMC4cNOGGyGR-W5MvqXEaPblrwPC@mail.gmail.com>
To: Michael Hausenblas <michael.hausenblas@deri.org>
Cc: public-rdf-dawg-comments@w3.org, Daniel Schwabe <dschwabe@inf.puc-rio.br>
Hi,

What would be available from /.well-known/sparql?

RFC 5785 says the URI should return metadata. This isn't completely
incompatible with also deploying the SPARQL endpoint to that location,
but doesn't seem quite right to me.

For example a domain may have several SPARQL endpoints, e.g. for
several datasets or with different policies, capabilities or access
control settings, so assuming a single Service Description seems
brittle.

Perhaps the response should be a document that links to available
SPARQL endpoints, from which the Service Descriptions can be
retrieved. This can just reuse the terms from the SD vocabulary:

E.g.:

<rdf:RDF
   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
   xmlns:sd="http://www.w3.org/ns/sparql-service-description#">
  <sd:Service>
    <sd:url rdf:resource="http://www.example/sparql/"/>
    ....
  </sd:Service>
</rdf:RDF>

The response from the well-known URI boot-straps us into a hypermedia
format in which we can follow links.

This could be specified as a separate small spec, not requiring any
specific changes to the SD document.

Cheers,

L.

On 3 June 2010 10:53, Michael Hausenblas <michael.hausenblas@deri.org> wrote:
>
> Dear SPARQL WG,
>
> I reviewed the SPARQL 1.1 Service Description W3C Working Draft 1 June 2010
> [1] - great job so far.
>
> Not sure if this is already on your radar, but in order to ensure a wide
> uptake concerning end-point discovery, I propose to register a well-known
> URI as per RFC5785 [2], i.e. to add the following to the SPARQL 1.1 Service
> Description document:
>
> ===
> 5. Well-Known URI Registration
>
> URI suffix:  sparql
>
> Change controller:  W3C.
>
> Specification document(s):  This document.
> ===
>
> This registry is quite new (as well as the RFC defining it) and I so far
> failed to figure what suffixes have been registered already. Nevertheless, I
> think it would tremendously help and hope that this is the right place to do
> it. If not, please let me know and I'll explore alternatives.
>
> Cheers,
>      Michael
>
> [1] http://www.w3.org/TR/2010/WD-sparql11-service-description-20100601/
> [2] http://tools.ietf.org/html/rfc5785#section-5.1
>
> --
> Dr. Michael Hausenblas
> LiDRC - Linked Data Research Centre
> DERI - Digital Enterprise Research Institute
> NUIG - National University of Ireland, Galway
> Ireland, Europe
> Tel. +353 91 495730
> http://linkeddata.deri.ie/
> http://sw-app.org/about.html
>
>
>
>
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-- 
Leigh Dodds
Programme Manager, Talis Platform
Talis
leigh.dodds@talis.com
http://www.talis.com
Received on Monday, 7 June 2010 10:39:20 GMT

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