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sparqlsemantic-weblinked-data

Is there a central SPARQL endpoint for the semantic web

We are going to have the semantic web. Now we have LOD cloud.

Every data set has its own SPARQL endpoint.

I can query the dataset triples.

How can I query the whole semantic web or LOD?

Solution

  • No, there is no such single SPARQL endpoint, because the Semantic Web is decentralized by design. However, SPARQL 1.1 supports federated queries over different SPARQL endpoints using the SERVICE keyword. See https://www.w3.org/TR/sparql11-federated-query/ for reference. More specifically, there is a mention in the literature about how to determine which data sources might be relevant for query answering at Internet scale:

    Hartig O., Bizer C., Freytag J.C. (2009) Executing SPARQL queries over the Web of Linked Data. In: Bernstein A. et al. (eds.) The Semantic Web – ISWC 2009. ISWC 2009. Lecture Notes in Computer Science, vol. 5823, pp. 293–309. Heidelberg: Springer. doi: 10.1007/978-3-642-04930-9_19