How does VoltDB differ from MySQL used with memcached?
Memcached is a distributed in-memory cache. It provides none of the reliability or consistency of an ACID-compliant SQL database. Memcached is often used as a cache in front of MySQL to improve performance of frequent transactions. But this requires the client application to manage the hash algorithms for both memcached and MySQL, as well as all of the transactional consistency and reliability between the two systems and across the cluster. VoltDB automates all of these functions with none of the penalties, while providing similar or better performance. In addition, caching can help improve read performance for products such as MySQL, but does not help scale write performance. VoltDB scales linearly for both read and write performance.