Suppose that we use the following standard backup strategy :
- Incremental Lvl 0 every Sunday
- Differential incremental Lv1 : all the other days
Backupset : ( 3:Sun/5:Mon/7:Tue /9:Wed/etc)
Suppose now that we hit a media failure at the end of the week (Saturday night for example) and when trying to recover the database we receive the following error :
The database (11.2.0.3.9) was successfully restored ,we applied the incremental backup of Monday but the Tuesday backup appear to be missing/Corrupted.A quick crosscheck confirm that :
The incremental backup was marked as EXPIRED. Let’s do a recover preview to check what will happen if we continue with the recover this way :
None of the remaining incremental backup will be applied, rman will need to apply all the generated archive log until the end of the weeks.This can be a huge amount of logs and can take a significant amount of time in a real case.But wait there is another way :
Let’s check the checkpoint SCN of the missing incremental backup and then recover the database until this scn and see what happen :
Et voila ! with this little trick we are now able to use the remaining incremental backup and speed significantly the recover process.
That’s it 😀
Hatem Mahmoud's blog 