Recovering a Database in NOARCHIVELOG Mode

If a media failure damages data files in a NOARCHIVELOG database, then the only option for recovery is usually to restore a consistent whole database backup.

To restore and recover the most recent whole database backup:

1. If the database is open, then shut down the database. For example, enter:

SHUTDOWN IMMEDIATE

1. If possible, correct the media problem so that the backup database files can be restored to their original locations.
2. Restore the most recent whole database backup with operating system commands. Restore all of the data files and control files of the whole database backup, not just the damaged files. If the hardware problem has not been corrected and some or all of the database files must be restored to alternative locations, then restore the whole database backup to a new location. The following example restores a whole database backup to its default location:

% cp /backup/*.dbf $ORACLE_HOME/oradata/trgt/

1. If necessary, edit the restored initialization parameter file to indicate the new location of the control files. For example:

CONTROL_FILES = "/new_disk/oradata/trgt/control01.dbf"

1. Start an instance using the restored and edited parameter file and mount, but do not open, the database. For example:

STARTUP MOUNT

1. If the restored data file names are different (such as when you restore to a different file system or directory, on the same node or a different node), then update the control file to reflect the new data file locations. For example, to rename data file 1 you might enter:

ALTER DATABASE RENAME FILE '?/oradata/trgt/system01.dbf' TO

                           '/new_disk/oradata/system01.dbf';

1. If the online redo logs were located on a damaged disk, and the hardware problem is not corrected, then specify a new location for each affected online log. For example, enter:

ALTER DATABASE RENAME FILE '?/oradata/trgt/redo01.log' TO

                           '/new_disk/oradata/redo_01.log';

ALTER DATABASE RENAME FILE '?/oradata/trgt/redo02.log' TO

                           '/new_disk/oradata/redo_02.log';

1. Because online redo logs are never backed up, you cannot restore them with the data files and control files. To enable the database to reset the online redo logs, you must first mimic incomplete recovery:

RECOVER DATABASE UNTIL CANCEL

CANCEL

1. Open the database in RESETLOGS mode:

ALTER DATABASE OPEN RESETLOGS;