If after-imaging is enabled for a database, you can recover from a lost or corrupted database backup as long as you have archived the AI files every time you backed up the database.
To restore the database from archived AI files:
1. Archive the current AI file to ensure that a second copy is available in case the original extents are damaged (for example, if you inadvertently overwrite the current busy AI file when restoring archived AI files in Step 3). The AI files have the information you need to bring the database backup files up to date.
Be sure to archive the AI files on different media than the database files backup.
2. Restore the backup you made immediately before the lost backup. If you are using incremental backups, you must restore the most recent full backup and then apply all the incremental backups to the full backup.
3. Restore the AI files you archived at the same time you made the backup that was lost or corrupted.
4. Use the RFUTIL ROLL FORWARD utility to roll forward the AI files you restored in Step 3. SeeAfter-imaging for more information.
5. Use the RFUTIL ROLL FORWARD utility to roll forward the current AI files (that is, the AI files in use since the lost backup).
6. Back up the database following the standard backup procedure described in BackingUp a Database.
7. Enable after-imaging and two-phase commit if you are using them.
8. Restart the database.
9. Restart any applications and continue database processing.
