This is a rough rendering of a page from the old Prevayler wiki. Please see the new wiki for current documentation.

Prevayler provides you with a way of finally being able to write a true object server with real, native Java objects.

Most questions people ask us are object questions or Java questions. They are perfectly valid questions but have nothing to do with Prevayler:

HowDoIQueryMyObjects? is an example. See the PrevalenceSkepticalFAQ for more.

See: AdvancedIssues.
What happens when I need to modify my objects? I mean, my application is perfectly running, but suddenly I need to add new functionality. So I modify my source code (i add/remove attributes from my objects) and I create a new version. This new version must use the same data than the old one.

How do I map the new version with the snapshot (and log files) of the version that was running before?

See SchemaEvolution.

I've written a tool to migrate data from an rdbms into prevayler, unfortunately the commandlog files invariably eat up my available inodes (many 1000's of files). I thought takeSnapshot() might clean up "old" command log, but it doesn't. Am i right in thinking that i can safely delete log files from times prior to a snapshot?

Yes. Is your name already among the PrevaylerPioneers? --KlausWuestefeld

I'm thinking of modifying the snapshot prevayler to nuke redundant logs after a snapshot. that should solve my problem.

Cool. If you make that an option through a system property, we can add that to Prevayler. --KlausWuestefeld