MusicBrainz-R2RML

R2RML mappings for the MusicBrainz schema on an entity-by-entity basis.

These can be run on the MusicBrainz server using ultrawrap, for which a script is provided (dump.sh). You must set an environment variable ULTRAWRAP_HOME.

Running musicbrainz-r2rml/dump.sh entity (where entity is artist, track, etc.) runs the appropriate set of mappings (e.g. mappings/artist.ttl) to produce output in the form of NTriples (e.g. output/artist.nt).

A virtual machine is available (for use with VirtualBox, VMware, etc.) with a replicated MusicBrainz database.

Note that the file musicbrainz_compile_config.properties must reflect your DB name:

• musicbrainz_db is the default for a snapshot
• musicbrainz_db_slave is the default for a replicated database

Please report any issues on our Jira tracker, under the LINKB project.

SPARQL endpoint

Uses MusicBrainz as a Virtual Knowledge Graph, where SPARQL queries are translated into SQL queries, which are then executed over the PostgreSQL database. In this setting, no materialization is needed.

Is based on Ontop and runs a Docker container.

Merging the mapping files

cd MusicBrainz-R2RML
docker build -t jena -f jena-Dockerfile .
docker run --rm jena riot --formatted=TURTLE  ./mappings/*.ttl > ./merged-mapping.ttl

Download the JDBC driver

Download the PostgreSQL JDBC driver and copy it into the jdbc folder.

Start the SPARQL endpoint

docker run --rm \
           -v $PWD:/opt/ontop/input \
           -v $PWD/jdbc:/opt/ontop/jdbc \
           -e ONTOP_MAPPING_FILE=/opt/ontop/input/merged-mapping.ttl \
           -e ONTOP_PROPERTIES_FILE=/opt/ontop/input/ontop.docker.properties \
           -p 8083:8080 \
           ontop/ontop-endpoint:4.1-snapshot

Visit http://localhost:8083/ .