How does VoltDB differ from a Key-Value Store (such as Cassandra)?
Key-Value stores are a mechanism for storing arbitrary data (i.e. values) based on individual keys. Distributing Key-Value stores is simple, since there is only one key. However, there is no structure within the data store and no transactional reliability provided by the system. VoltDB provides the ability to store either structured or unstructured data, while at the same time providing full transactional consistency, reliability, and standard data access syntax through ANSI SQL. VoltDB can even define a transaction that includes reads and writes across multiple keys. Finally, VoltDB provides comparable or better performance in terms of throughput.
