Redo Area 

The redo area is a storage area reserved for log entries in the data devspace.

When log entries are being imported, they are copied to the redo area of the data devspace. Firstly, this allows the log entries to be read in advance to establish whether or not it is worth recovering transactions because they have a rollback instruction at the end. Secondly, it allows log entries which do have to be imported to be dealt with simultaneously.

The redo area is used for restarting the database instance. While the database is running it is not available for permanent data objects.