- What is the recovery window in RMAN? Could you explain with a simple example?
- We are currently using hot, cold and imp and exp backups, but management has decided to switch from traditional backups to RMAN backups in Oracle 9i. Are there any special steps to take into consideration when switching from traditional backups to RMAN in Oracle 9i. We have 4 terabytes of data.
The recovery window in RMAN dictates which files to be backed up based on how many days of recovery would be needed to restore the database to the current point in time. For instance, if you have defined a recovery window of seven days, and you backed up half your database 10 days ago and the other half three days ago, then half the database is outside that recovery window and would need to be backed up.
Your RMAN backup and recovery techniques are slightly different in RMAN than with the traditional hot and cold methods. You will use different scripts, and you may want to implement a Recovery Catalog as well. RMAN also has many features not available with your traditional backups, especially with very large databases. For instance, RMAN can skip all tablespaces that are marked as READ ONLY (assuming you have previously backed them up). Why back up READ ONLY tablespaces again when their contents have not changed? I recommend looking at RMAN's features to see which one can be used to your advantage now that you are making the switch. I also highly recommend that you test, not only your backups with RMAN, but also a variety of recovery scenarios with RMAN.
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