The file that stores the changes made to a disk in undoable or nonpersistent mode. You can permanently apply the changes saved in the redo log to a disk in undoable mode so they become part of the main disk files. For a disk in nonpersistent mode, however, the redo-log file is deleted when you power off or reset the virtual machine without writing any changes to the disk.

a set of operating system files, external to the database files, that records all changes made to the database, regardless of whether those changes are committed or rolled back

A redo log can be either an online redo log or an archived redo log. The online redo log is a set of two or more redo log groups that records all changes made to Oracle datafiles and control files. An archived redo log is a copy of an online redo log that has been written to an offline destination. See Also: archived redo log, online redo log

A set of files that protect altered database data in memory that has not been written to the datafiles.

A sequential log of all changes made to the data. The redo log is written and used in the event of a failure that prevents changes from being written to disk. The redo log consists of two or more redo log files.

A file containing redo records. There are three types of redo logs: online redo logs, standby redo logs, and archived redo logs. The online redo log is a set of two or more files that records all changes made to datafiles and control files. The LGWR process records the redo records in the log. The current online redo log is the one to which LGWR is currently writing. The standby redo log is an optional location where the standby database can store the redo data received from the primary database. This redo data can be stored on the standby location using either standby redo logs or archived redo logs. The archived redo log, also known as the offline redo log, is a copy of the online redo log that has been copied to an offline destination. If the database is in ARCHIVELOG mode, the ARC process or processes copy each online redo log to one or more archive log destinations after it is filled. See also archived redo log, ARCHIVELOG mode, current online redo log, log switch, online redo log, and standby redo log