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Questions tagged [rdf4j]

Eclipse RDF4J is a Java framework for working with RDF, SPARQL, and OWL. It offers a set of libraries and APIs for parsing, writing, scalable storage and reasoning, as well as a Workbench and Server application for deployment of RDF databases. This tag should be used for all questions regarding use of the RDF4J libraries and tools.

Eclipse RDF4J is a Java framework for parsing, writing, storing, querying and reasoning with RDF, SPARQL, and OWL. It offers a set of libraries and APIs for parsing, writing, scalable storage and reasoning, as well as a Workbench and Server application for deployment of RDF databases.

Eclipse RDF4J is the successor of the OpenRDF Sesame project.

For more information see the RDF4J community website.

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Removing triples from RDF4j Native Store seems quite slow

I've got an RDF4j disk based Native Store with roughly 9M of triples. I'm trying to improve the performance of deleting of about 4K triples which now takes ~20 seconds. I've tried: 1 Repository rep = new SailRepository(new NativeStore(new…
Alex Boyarintsev
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How to execute a SPIN rule using RDF4J API on Ontotext GraphDB

I am using RDF4J to create a repository on Ontotext GraphDB, import an RDF/XML to it and execute a SPIN rule. We can create and configure the repository as shown here…
Zorz Bronze
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How get UpdateExpr when i execute insert query RDF4J

problem with insert query, can't pars simple statements Example: query: PREFIX dc: INSERT DATA { dc:title "A new book"; dc:creator "A.N.Other"…
Gevorg Arutiunian
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Cannot import RDF url content into GraphDB

I have on a Web server an URL which serializes a RDF triplestore with Python module rdflib. I want to import this content into GraphDB. The rdflib.serialize output format is "xml". The MIME type of the HTTP header is "xml/rdf" but the result is the…
remi.chateauneu
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RDF4J: Parse query result from endpoint and store it as ntriples file (malformed query)

in this endpoint there is an option to get the result of a query in N-triples format. I want to do the same with the rdf4j library when connecting to the endpoint and save the result in an ntriples format file. So far, I've used a graphQuery…
Manos Ntoulias
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Unable to execute SPARQL Select Query using GraphDB REST interface

I have a graphDB instance running on a VPS and i want to get the list of Organisations with hasUnit relation. The following query executes fine on the SPARQL execution page: PREFIX org: SELECT (?s AS ?Organization)…
coderdecoder
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Spatial SPARQL Queries in RDF4J with Lucene support

I am testing RDF4J on spatial queries. I have deployed the RDF4J Server and Workbench apps on Appache Tomcat 9.0.12. My current dataset has 853 LineStrings and 88 Polygons represented asWKT fields. But the performance of query varied from type of…
AMIR RAZA
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Querying FactForge Sparql Endpoint with RDF4J returning error

I'm trying to query Factforge Sparql endpoint with RDF4J but I receive an error. I use RDF4J V: 2.3.2 with Maven. I set my proxy settings on Java with: System.setProperty("https.proxyHost", PROXY_HOST); System.setProperty("https.proxyPort",…
Batuhan Tüter
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RDF4J and GEOSparql spatial functions not working (or not implemented)

I'm using RDF4J as I got caught by the advertised implementation of GEOSPARQL (which I didn't find in other RDF frameworks). I followed basic guides and tutorial, but unfortunately I haven't been able to perform basically any of the advertised…
McKracken
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SPARQL: Insert query results as RDF LIST

I want to get from graph A results bound to a specific variable lets say ?s. Next I want to insert those results as an RDF list in graph B. This is my SPARQL Update: prefix foo: insert { graph { ?var…
whitefang1993
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Create a repository on a remote server with RDF4J

I've been trying to create a new repository on a remote GraphDB server using RDF4J, but I'm having problems. This runs, but is seemingly not correct HTTPRepositoryConfig implConfig = new HTTPRepositoryConfig(address); RepositoryConfig repoConfig =…
Seymoure Frye
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RDF4j and GraphDB repository connection

I've a problem with rdf4j: i want to delete from my GraphDB repository "Feed" all the triples with feed:hashCode as predicate. The first query verifies if there is a triple with the url parameter as subject, feed:hashCode as predicate, and hash…
Valentina
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Why is adding an RDF dump (InputStream) to a RDF4J repository so slow (in Java)?

I am loading an RDF rump from the web as an InputStream, which contains between 120 and 1500 triples. On average, clearing the context takes about half a second, while adding the triples takes around 74 seconds for the 120 triples. The physical file…
matentzn
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How do I enter a query with a PREFIX in RDF4J Console?

sparql> PREFIX ab: Executing update... Update executed in 160 ms sparql> SELECT ?craigEmail WHERE { ?person ab:firstName "Craig" } Malformed query:…
Deana H.
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Why does SPARQL LIMIT on Inner Query seem to limit the outer query under RDF4J?

I'm using RDF4J version 2.2.2 workbench and server under Windows 10. I need to use an inner query to limit results. My particular application is in accumulating an event concept from a series of correlated reports. Each report has a time stamp as…
Greg Cox
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