Are there some Linked data websites use distributed sparql Endpoints and provide cross-domain data search services?

Build a Solid App Linked Data
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Is there a website x:

  • Searching rdf resources from distributed sparql Endpoints.
  • Rdf resources come from multiple subject areas and are related .
  • Provide some semantic services such as QA, route search …

I found that:

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The Linked Data Fragments website provides a demo how some parts of your question can be solved. With Comunica you can do federated SPARQL queries from your browser using a variety of endpoints.

See : try the DBpedia,Harvard,VIAF example that was created do demonstrate how , for instance, libraries can use federated queries to match book authors against VIAF (a database of author names) and DBPedia (to provide more information authors).

We used this technique at Ghent University Library to enrich our catalog with global unique identifiers for book authors.

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Hi, @hochstenbach .

Comunica is great.

It’s more like a tool, supporting command line, JavaScript, Docker, etc., and also supports SPARQL search across multiple endpoints.

But it’s probably not what I’m looking for, it doesn’t seem to dig deeper into the semantics,

such as using the relationship between data across endpoints to query, revealing hidden relationships between endpoints, etc.

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such as using the relationship between data across endpoints to query, revealing hidden relationships between endpoints, etc.

Comunica does have support for link traversal and there are some open challenges in SolidLab which look into being able to to use other endpoints (such as SPARQL endpoints and LDF) in the traversal process. These challenges are likely to be implemented as additional components for Comunica.

But it’s probably not what I’m looking for, it doesn’t seem to dig deeper into the semantics,

I’m not quite sure what you specifically mean by this; but if you are after a RDF reasoner then there are also Comunica components for that. We are hoping to improve the capabilities of that reasoner in the future using eye-js which has support for N3 Rules, RDF Surfaces and all of the other wonderful things that eye supports.

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Thanks, @jeswr an apology for replying so late.

Comunica is a great SPARQL federated query engine.

But what I’m looking for is application websites that are based on these federated query engines, so are these federated query engines being used well?

Websites like http://linkedlifedata.com/ that I have read so far do not actually use SPARQL federated query technology,
but localize the data and use a uniform IRI prefix to store different datasets as a named graph.

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A few examples off the top of my head:

You’d also be able to find more by looking at the dependency graphs of federated query engines like comunica (Network Dependents · comunica/comunica · GitHub).

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Thanks, This information is very useful, I will study it.