Note_Tech

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DBA2 - Recoverability

Configure your database for maximum recoverability by:

To provide the best protection for your data, you must:

Schedule regular backups:
- Most media failures require that you restore the lost or damaged file from backup.
Multiplex control files:
- All control files associated with a database are identical.
- Recovering from the loss of a single control file is not difficult; recovering from the loss of all control files is much more challenging.
- Guard against losing all control files by having at least two copies.
Multiplex redo log groups:
- To recover from instance or media failure, redo log information is used to roll data files forward to the last committed transaction.
- If your redo log groups rely on a single redo log file, the loss of that file means that data is likely to be lost.
- Ensure that there are at least two copies of each redo log group; if possible, each copy should be under different disk controllers.
Retain archived copies of redo logs:
- If a file is lost and restored from backup, the instance must apply redo information to bring that file up to the latest SCN contained in the control file.
- With the default setting, the database can overwrite redo information after it has been written to the data files.
- Your database can be configured to retain redo information in archived copies of the redo logs. This is known as placing the database in ARCHIVELOG mode. You can perform configuration tasks in Enterprise Manager Cloud Control or by using the SQL command line.