Log pages are the main memory units used in redo log management. Log pages are 8 KB in size.
A user task writes its redo log entries to the log pages of the log queue. Each log page is assigned a log queue sequence number that specifies the time the redo log entry was written to the log queue.
Later, the log writer writes the log pages to the log area. Log pages from the log queue that were not full when they were written on, remain in the log queue and continue to be written on until the next write operation, when they are written to the log area. The log writer is configured so that it always writes the same log page to the same physical place in the log area.
When the log writer writes a log page from the log queue to the log area, it assigns a log sequence number and a timestamp to it. The log sequence numbers can be used to determine the unique sequence of the log pages in the log area. The timestamp is used to recover the database with the same status that it had at a particular point in time.