Prevayler

Prevayler is a free , mainly in Java -written persistence -layer for Plain Old Java Objects (POJOs). Prevayler is known to be very fast, fault-tolerant and offers load balancing.

Prevayler differs from other persistence layers such as TopLink or Hibernate in that the objects are not stored in a relational database , but are kept in the main memory. There is only a dump to a non-volatile medium such as a hard drive at certain intervals.

However, it is problematic to keep all objects permanently in memory. For some applications this is a knockout criterion, as the amount of data can quickly become larger than the main memory can handle. Prevayler does not support the explicit resetting of the saved data.

See also

• Using Prevayler as an embedded file system

Web links

• http://sourceforge.net/projects/prevayler
• http://www.prevayler.org/
• Results of speed test
• http://bbooprevalence.sourceforge.net/ (Prevayler implementation in C #)
• http://xprevail.sourceforge.net/ (Prevayler implementation in Delphi)