The GraphDB Connectors enable the connection to an external component or service, providing full-text search and aggregation (Lucene, Solr, Elasticsearch), or querying a database using SPARQL and executing heterogeneous joins (MongoDB). They also offer the additional benefit of staying automatically up-to-date with the GraphDB repository data.

Full-text search and aggregation connectors

The Lucene, Solr, and Elasticsearch Connectors provide synchronization at entity level, where an entity is defined as having a unique identifier (URI) and a set of properties and property values. In RDF context, this corresponds to a set of triples that have the same subject. In addition to simple properties (defined by a single triple), the Connectors support property chains. A property chain is a sequence of triples where each triple’s object is the subject of the subsequent triple.

GraphDB SE comes with the following FTS connector implementations:

MongoDB integration

The MongoDB integration allows you to query MongoDB databases using SPARQL and to execute heterogeneous joins. A document-based database with the biggest developer/user community, MongoDB is part of the MEAN technology stack and guarantees scalability and performance well beyond the throughput supported in GraphDB. The integration between GraphDB and MongoDB is done by a plugin that sends a request to MongoDB and then transforms the result to RDF model.