The Apache Cassandra database is the right choice when you need scalability and high availability without compromising performance. Linear scalability and proven fault-tolerance on commodity hardware or cloud infrastructure make it the perfect platform for mission-critical data. Cassandra's support for replicating across multiple datacenters is best-in-class, providing lower latency for your users and the peace of mind of knowing that you can survive regional outages.
TDB is a component of Jena for RDF storage and query. It support the full range of Jena APIs. TDB can be used as a high performance RDF store on a single machine. This documentation describes the latest version, unless otherwise noted.