Journals and journal receivers

Each database includes recovery journals and journal receivers, which are used to recover from application or system errors. In combination with database backups, journals are used to recover the consistency of the database up to a point in time when an error occurred.

All instances have journals associated with them. These journals keep records of database changes. Journals prevent a failure (system power, application error) from leaving a database in an inconsistent state. They restore the state of a database to the point before the change. Journals can also enable forward recovery to any point in time before the failure.

In planning for disaster recovery, be sure to remember that journals must be stored off site, or at least safely away from the disaster, in order to recover your database beyond the point of the last full, off line backup.