RDF support is a core feature of Fedora 4, used as the primary data format for the REST API. A triplestore is not bundled into the repository itself. Instead, Fedora 4 sends events when the repository is updated, and the Indexer copies RDF from the repository to an external triplestore to keep it in sync with the repository. This pattern, which is also used for search functionalty for the same reasons, allows maximum flexibility about what triplestore to use, and removes the overhead of keeping the triplestore in sync from the core repository functionality.
Indexer Configuration
Creating, modifying or deleting resources in the repository generates JMS events. The indexer listens to those events, and retrieves the RDF from the repository. The indexer can be configured to process the event in various ways, such as copying the resource RDF to a triplestore or indexing in Solr.
