When you create a new database, it is important to configure the database so you can recover your data in the event of a system failure. Use this page to specify a fast recovery area and to enable archiving.
The Fast Recovery Area can be used to recover data that would otherwise be lost during a system failure; this location is also used by Enterprise Manager if you have enabled local management and daily backups on the Management Options page shown previously in the Database Configuration Assistant.
The fast recovery area is an Oracle-managed directory, file system, or Automatic Storage Management disk group that provides a centralized disk location for backup and recovery files. Oracle creates archived logs in the fast recovery area. Enterprise Manager can store its backups in the fast recovery area, and uses it when restoring files during media recovery. Oracle recovery components interact with the fast recovery area ensuring that the database is completely recoverable using files in fast recovery area. All files necessary to recover the database following a media failure are part of fast recovery area.
Use the Fast Recovery Area field to specify the location and size of your fast recovery area. You can use variables to identify some standard locations, such as the Oracle home. To review or add additional variables, click File Location Variables at the bottom of the Recovery Configuration page.
The fast recovery area serves as a type of disk cache for tape backups, shortening recovery times, and allowing automated disk backup management. When you specify a fast recovery area, you must set the size of the recovery area in the Fast Recovery Area Size field.
When you enable archiving, the database archives its redo logs. Archived redo logs can be used to recover a database, update a standby database, or to gain information about the history of a database using the LogMiner utility.
Enabling archiving is the same as turning on Archive Log Mode in the Oracle
Enterprise Manager, or
running the database in ARCHIVELOG mode. This means a group of redo log files cannot be reused by the log writer (LGWR) process until the group is archived. If the database is running in NOARCHIVELOG mode, then when a group becomes inactive after the LGWR process switches to a new group, the inactive group is available for immediate reuse by the LGWR process. You must enable
archiving to make the database recoverable from disk failure.
The NOARCHIVELOG mode protects a database from instance failure but not from media failure. Only the most recent changes made to the database, which are stored in the online redo log groups, are available for instance recovery. To restore a database operating in NOARCHIVELOG mode, you can use only entire database backups taken while the database is closed. Therefore, if you decide to operate a database in NOARCHIVELOG mode, back up the entire database at regular, frequent intervals.
The archiving of redo log files has these advantages:
A database backup, together with online and archived redo log files, guarantees that you can recover all committed transactions in the event of an operating system or disk failure.
You can recover the database using a backup that was taken while the database was open and being used, as long as you have a copy of the archived log files that were written while the database was being backed up.
You can perform online tablespace backups, and use these backups to restore a tablespace following media failure.
You can keep a standby database current with its original database by continuously applying the original archived redo logs to the standby database.
Before you can archive redo logs, you must determine the destination to which you will archive. Oracle recommends that the archive log be stored in a fast recovery area because it can simplify backup and recovery operations for your database.
Important: Ensure that you have allocated sufficient disk space for the archived logs. In case of insufficient disk space during archiving, the database can hang.
You can use the default archive log mode settings. Click Edit Archive Mode Parameters to provide specific archive parameters for your database.
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