The ARCHIVELOG mode
Databases can be run in one of two modes — the ARCHIVELOG
mode or the NOARCHIVELOG
mode. In NOARCHVIELOG
mode, the redo log files are reused by the Oracle database engine without being copied to an offline location. In ARCHIVELOG
mode, Oracle copies the filled online redo log files to one or more offline locations before they are reused. These redo log files, which are saved offline, are called archived redo log files. The ARCH process is responsible for archiving when automatic archiving is enabled. You use the archived redo log files to recover a database and update a standby database.
The ARCHIVELOG
mode is very important for mission-critical production databases. Databases can be backed up in the open
mode when running in the ARCHIVELOG
mode. Also, the ARCHIVELOG
mode provides point-in-time recovery. It is generally not necessary for test and development databases.
Placing a database in the ARCHIVELOG mode
To place a database in the ARCHIVELOG
mode, perform the following...