I agree with Saurabh -- that's a question we can at best only provide personal preferences on. RA creates and uses its own schema in Oracle DB, hence any method for backing up Oracle DB schemas in general should be valid. Because that database is not one of our products, this would be a question better suited for Oracle directly. They also have their own customer forums where you could have such a discussion. That said, I would be interested to see what other customers' opinions are here in the Communities on this topic.
For backup concerns directly related to Release Automation, the following KB details what all needs to be backed up to prepare for any disaster recovery scenario in RA: TEC1942295.