RMAN recover : Incremental backup GAP

Suppose that we use the following standard backup strategy :

  • Incremental Lvl 0  every  Sunday
  • Differential incremental Lv1 : all the other days

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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 :

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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 :

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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 :

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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 :

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Let’s check the checkpoint SCN of the missing incremental backup and then recover the database until this scn and see what happen :

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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 😀

 

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