Tuning Log Switches

Another good Redo Log article:
Tuning Log Switches

Oracle's Redo Log

An interesting article regarding Redo Logs:

Oracle's Redo Log

The redo log makes it possible to replay SQL statements. Before Oracle changes data in a datafile it writes these changes to the redo log. If something happens to one of the datafiles, a backed up datafile can be restored and the redo, that was written since, replied, which brings the datafile to the state it had before it became unavailable. The same technique is also used in a data guard environment (standby databases): One database (the primary database) records all changes and sends them to the standby databases. These standby databases in turn apply (reply) the arrived redo which keeps the synchronized with the primary database.