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  • VOS.VirtBulkRDFLoaderExampleDbpedia(Last) -- Owiki? , 2018-04-13 12:05:45 Edit owiki 2018-04-13 07:05:45

    Virtuoso Bulk Load Example: DBpedia data sets

    The following example demonstrates how to upload the DBpedia data sets into Virtuoso using the Bulk Loading Sequence.

    1. Assuming there is a folder named "tmp" in your filesystem, and it is within a directory specified in the DirsAllowed param defined in your virtuoso.ini file.
    2. Load the required DBpedia data sets into the "tmp" folder
      • The latest data sets can be downloaded from the DBpedia Download page. Note the compressed bzip'ed ".bz2" data set files need to be uncompressed first as the bulk loader scripts only supports the auto extraction of gzip'ed ".gz" files.
    3. If it hasn't already been, execute the Bulk Loading script.
    4. Register the graph IRI under which the triples are to be loaded, e.g., "http://dbpedia.org":

      SQL> ld_dir ('tmp', '*.*', 'http://dbpedia.org'); Done. -- 90 msec.

      • Note that while this procedure will also work with gzip'ed files, it is important to keep the pattern: <name>.<ext>.gz, e.g., 'ontology.owl.gz' or ontology.nt.gz
      • Note that if there are other data files in your folder (tmp), then their content will also be loaded into the specified graph.

    5. Create a file named global.graph in the "tmp" folder, with its entire content being the URI of the desired target graph, e.g.,


    6. Finally, execute the rdf_loader_run procedure. This may take some time, depending on the size of the data sets.

      SQL> rdf_loader_run (); Done. -- 100 msec.

    7. As a result, the Virtuoso log should contain notification that the loading has completed:

      10:21:50 PL LOG: Loader started 10:21:50 PL LOG: No more files to load. Loader has finished

    8. Run a checkpoint to commit all transactions to the database.

      SQL> checkpoint; Done. -- 53 msec.

    9. To check the inserted triples for the given graph, execute a query similar to --

      SQL> SPARQL SELECT COUNT(*) FROM <http://dbpedia.org> WHERE { ?s ?p ?o } ;

    10. Install the DBpedia and RDF Mappers VAD packages, using either the Virtuoso Conductor or the following manual commands:

      SQL> vad_install ('dbpedia_dav.vad', 0); SQL> vad_install ('rdf_mappers_dav.vad', 0);

    11. The Virtuoso-hosted data set can now be explored using a HTML browser, or queried from the SPARQL or Faceted Browser web service endpoints. For example, with the DBpedia 3.5.1 data sets, a description of the resource Bob Marley can be viewed as: http://<your-cname>:<your-port>/resource/Bob_Marley