This is a rough rendering of a page from the old Prevayler wiki. Please see the new wiki for current documentation.
Keeping everything in RAM is unsafe.
It's unsafe, indeed, but not when you have all the changes to your application's business objects persisted, and have the possibility of taking a snapshot of your running system.
It's not possible or viable to make SchemaEvolution.
It may be hard, but it's not impossible or inviable, given the right strategies are used. See SchemaEvolution
for more discussion about it.
Prevayler is just another unfinished in-memory database.
Prevalence is a different concept. Prevayler
will not regress into a database nor merge with some existing database. See PrevaylerIsNotADatabase