Re: Discovering a query endpoint associated with a given Linked Data resource

As far as LDF endpoints are concerned, I suggest you use the API provided
at http://index.lodlaundromat.org. This index links resources (around 3.5
billion) to documents (657,880 and counting) they occur in. These documents
are hosted by the LOD Laundromat via Triple Fragments APIs.

For more information about LOD Laundromat, see http://lodlaundromat.org and
our recent ISWC and ESWC publications:
Beek, W. & Rietveld, L & Bazoobandi, H.R. & Wielemaker, J. & Schlobach, S.:
LOD Laundromat: A Uniform Way of Publishing Other People's Dirty Data.
Proceedings of the International Semantic Web Conference (2014).
Rietveld, L. & Verborgh, R. & Beek, W. & Vander Sande, M. & Schlobach, S.:
Linked Data-as-a-Service: The Semantic Web Redeployed. Proceedings of the
Extended Semantic Web Conference (2015).

Best, Laurens


On Wed, Aug 26, 2015 at 10:45 AM, Nandana Mihindukulasooriya <
nmihindu@fi.upm.es> wrote:

> Hi,
>
> Is there a standard or widely used way of discovering a query endpoint
> (SPARQL/LDF) associated with a given Linked Data resource?
>
> I know that a client can use the "follow your nose" and related link
> traversal approaches such as [1], but if I wonder if it is possible to have
> a hybrid approach in which the dereferenceable Linked Data resources that
> optionally advertise query endpoint(s) in a standard way so that the
> clients can perform queries on related data.
>
> To clarify the use case a bit, when a client dereferences a resource URI
> it gets a set of triples (an RDF graph) [2].  In some cases, it might be
> possible that the returned graph could be a subgraph of a named graph /
> default graph of an RDF dataset. The client wants to discover if a query
> endpoint that exposes the relevant dataset, if one is available.
>
> For example, something like the following using the "search" link relation
> [3].
>
> ------
> HEAD /resource/Sri_Lanka
> Host: http://dbpedia.org
> ------
> 200 OK
> Link: <http://dbpedia.org/sparql>; rel="search"; type="sparql", <
> http://fragments.dbpedia.org/2014/en#dataset>; rel="search"; type="ldf"
> ... other headers ...
> ------
>
> Best Regards,
> Nandana
>
> [1]
> http://swsa.semanticweb.org/sites/g/files/g524521/f/201507/DissertationOlafHartig_0.pdf
> [2]
> http://www.w3.org/TR/2014/REC-rdf11-concepts-20140225/#section-rdf-graph
> [3] http://www.iana.org/assignments/link-relations/link-relations.xhtml
>



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