integration of lodstats and personalization features based on it
by Sven R. Kunze

Extracting semantic data of CKAN – ckanext-semantic

A extension for CKAN


  • enhanced search (search after vocabularies, classes, properties, geographical and temporal coverage)
  • new search type: SPARQL
  • new subscription type: SPARQL subscriptions
  • enriched dataset page (used vocabularies, geographical and temporal coverage)
  • similar datasets
  • personalized recommendations

Installation instructions

  • install Virtuoso v6
  • install FedX v2 (in case of more than 1 endpoint)
  • apply db.sql file to add necessary tables
  • install LODStats and Redland rdflib:

    pip install -e git+
    pip install -e git+
  • add to your CKAN configuration file:

    # add this to your plugins
    ckan.plugins = semantic
    # constants for dataset statistics update
    ckan.semantic.waiting_time = 1
    ckan.semantic.ratio_old_new = 0.4
    # credentials for sparql clients (for delete and insert)
    # pattern: SPARQL_{attribute}_{role}; attribute in [username, password, hostname]; role in [root]
    ckan.semantic.SPARQL_username_root = dba
    ckan.semantic.SPARQL_password_root = dba
    ckan.semantic.SPARQL_hostname_root = localhost
    # federation tool fedX required
    ckan.semantic.FedX = {path to your FedX}/lib/*
    # endpoints
    # pattern: SPARQL_endpoint# from 0 to 20
    ckan.semantic.SPARQL_endpoint1 = http://localhost:8890/sparql
    ckan.semantic.SPARQL_endpoint1_name = CKAN Store
    ckan.semantic.SPARQL_endpoint2 =
    ckan.semantic.SPARQL_endpoint2_name = DBPedia Store
  • create CRON jobs to run these commands on a periodical basis:

    paster semantic update_dataset_due_statistics --config=../ckan/development.ini
    paster semantic update_dataset_statistics {dataset_name} --config=../ckan/development.ini
    paster semantic update_vocabulary_statistics --config=../ckan/development.ini
  • you may need a key for cloudmade; add it here:


Copyright and License

© 2013 Sven R. Kunze

Licensed under the GNU Affero General Public License (AGPL) v3.0

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