Look Ma' No Database (with Prevayler)

Learn about Java Prevalence; an alternative to traditional relational databases.

Come and learn about a revolutionary and controversial way to persists data in your Java applications. Prevayler is closer to an object database than it is to a relational database. It works on the premise that you can and should keep all of data in memory if you have enough RAM. To provide persistence for you data you start your work based on a snapshot of your data, as you data is manipulated the deltas are stored to disk individually at predefined interval. Optionally, you can take a complete snapshot of the data that will encompass all of the changes. When your application starts back up the latest snapshot is loaded and all of the existing deltas are applied, bringing the system to the last state of the last run. The rational behind this is that RAM is cheaper than hard drive space and it’s ideally suited for fast access. Prevayler is not for everyone but for the cases where it makes sense to use it can deliver lighting fast applications.