Re: LOD Links and datasets

On 8/13/20 6:03 AM, Jean-Claude Moissinac wrote:
> Someone suggested to me the use of void:sparqlEndpoint
> I think that it is a part of the answer
> with void:sparqlEndpoint <https://www.w3.org/TR/void/#sparql>, we says
> that triples of a dataset are available in a specified sparql endpoint
> Then, we need to say that some links in our dataset are 'member' of
> that other dataset
> I am investigating further if VOID enables that
>
> void:Linkset seems to be part of the answer
> with linkset, I can say that my dataset is linked by a given property
> to another dataset
> but I have no way to say that some objects are in a dataset and some
> others objects are in another dataset
> a good example is owl:sameAs; how can I say that if the object follows
> the template http://dbpedia.org/..., it must be searched in
> http://dbpedia.org/sparql when if it follows the template
> http://fr.dbpedia.org/... it  must be searched in
> http://fr.dbpedia.org/sparql
>
> It seems to me that it is very important for the LOD that when we
> access a dataset, we must be able to find a dataset access point for
> the externally linked entities; it is necessary to enable powerful
> federated queries.
> --
> Jean-Claude Moissinac


Hi Jean-Claude,

In regards to Linked Data, there are two routes to federation:

[1] Implicit -- this manifests when the dataset is published using
Linked Data principles and SPARQL query solution production pipeline
incorporate URI-variable and URI-constant derefrence

[2] Explicit -- what you are referring to with SPARQL-FED in mind.

Naturally, you can also mix these approaches.

#1 isn't very common as very few DBMS engines and stores implements this
powerful aspect of Linked Data exploitation. Thus far, I am only aware
of our Virtuoso DBMS handling option 1, all other implementations have
occurred within frameworks and browser tools.

Links:

[1] http://wifo5-03.informatik.uni-mannheim.de/bizer/ng4j/semwebclient/
-- Semantic Web Client Library

[2] https://github.com/timbl/tabulator -- TimBL's Tabulator

[3]
https://medium.com/virtuoso-blog/what-is-a-virtuoso-sparql-endpoint-and-why-is-it-important-5244df738a3e
-- Virtuoso SPARQL Query Services

[4] https://twitter.com/kidehen/status/1038927045626159104 -- Virtuoso
example


>
>
>
> Le mer. 12 août 2020 à 08:43, Jean-Claude Moissinac
> <jean-claude.moissinac@telecom-paristech.fr
> <mailto:jean-claude.moissinac@telecom-paristech.fr>> a écrit :
>
>     Hello
>
>     Is there a recommended method to say in a rdf graph something like
>     'all links in that graph (or dataset) on the model
>     http://mydomain.dom/.../* are described in the sparql access point
>     http://anotherdomain.dom/.../sparql'?
>     --
>     Jean-Claude Moissinac
>

-- 
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