2

In the GraphDB documentation, I see that "the dataset’s default graph contains the merge of the database’s default graph AND all the database named graphs." This means that "if a statement ex:x ex:y ex:z exists in the database in the graph ex:g" then a query such as SELECT * { ?s ?p ?o } will return the triple ex:x ex:y ex:z

I am wondering if there is a setting which can be triggered either via the web interface or via the RDF4J/OpenRDF API which will disable this behavior in a specified GraphDB repository. That is, for the purposes of my project I would prefer to have triples which are stored in named graphs to only appear in results which specifically query that named graph.

I have not seen anything like this searching through the documentation or on the settings available on the web interface, but maybe somebody here knows something I don't.

EDIT: I am not looking for a SPARQL solution to this problem. I know that I can query just the default graph using SPARQL, but I want to be able to use the query SELECT * { ?s ?p ?o } and only see results which are in the default graph by default.

Stanislav Kralin
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hayfreed
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1 Answers1

4

GraphDB/RDF4J have a different interpretation than Jena how to query the default graph. The only easy way to query only explicit statements in the default graph is to use the special graph sesame:nil. The SPARQL-based solution is to write:

PREFIX sesame: <http://www.openrdf.org/schema/sesame#>
SELECT ?s ?p ?o
FROM sesame:nil
WHERE {
   ?s ?p ?o .
} LIMIT 100

I don't think there is any easy non-SPARQL based solution like changing a configuration option or even use this special graph over the SPARQL Graph Store protocol.

vassil_momtchev
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