Look at Prevayler and HAppS, two systems that don't use a database at all. In-memory persistence with write-ahead logging, and they handle give-or-take 1000 hits/s on a stock Xeon server.
Terracotta may be a good solution for Java.
Look at Prevayler and HAppS, two systems that don't use a database at all. In-memory persistence with write-ahead logging, and they handle give-or-take 1000 hits/s on a stock Xeon server.