Redo Log Management 
During online logging, the redo log entries are written and managed.
· Active components: transactions in user tasks, log writer
· Storage units: log queue, log area
Prerequisites
Use
Redo log management plays a part in the following actions:
· During execution of a modifying transaction, the redo log entries are included in the log queue. The log writer writes the log pages from the log queue to the log area.
· During a log backup, information is obtained on whether entries from the log area are to be backed up, and if so, how many.
· For display on the monitor, information is obtained on waiting periods, and the type of access to the entries in the log queue.
· In the case of a restart or recovery, the required redo log entries are read from the log area.
· The database parameters and other internal information that controls logging are stored in the log area and updated at regular intervals.