Oracle Database Discussions

I am coming up with a list of scenarios to test our backups. Here are the scenarios that I can come up with. Can you guys think of more?

1. Whole database restore to current
2. whole database restore to point in time
3. missing datafile
4. missing control file
5. restore dropped table to current
6. restore dropped table to point in time


Also, I plan to test back ups as often as I can but of course this will depend on the workload one has, but how often do you guys think recovery tests should happen? monthly? quarterly?

Thanks!