December 2002
Intermediate to advanced
928 pages
85h 29m
English
Once Oracle fills one redo log file, it automatically begins to use the next log file. Once the server cycles through all the available redo log files, it returns to the first one and reuses it. Oracle keeps track of the different redo logs by using a sequence number. As the server fills each redo log file and moves on to the next one, it increments an internal counter called the redo log sequence number. This sequence number is recorded inside the redo log files as they are used. Oracle uses this internal number to properly sequence the logs, even though a reused log file may have the name initially created for an earlier redo log.