Prepare a Backup Strategy Before Upgrading Oracle Database

You must design and carry out an appropriate backup strategy to ensure a successful upgrade.

For Oracle Database Enterprise Edition, the primary fallback mechanism is Flashback Database. However, Flashback Database can't be used to revert an unplug-plug upgrade or PDB conversion. For unplug-plug upgrades, rely on other fallback strategies, such as an RMAN backup.

If you use AutoUpgrade, then Oracle recommends that you specify target_pdb_copy_option=file_name_convert, in the AutoUpgrade configuration file, where file_name_convert is a convert pattern prefixed to the data files. When you do that, AutoUpgrade directs the database to create copies of the data files before plugging in the database. Choosing to use this method enables you to use the original database as a fallback. However, be aware that when you create data file copies, the upgrade requires additional disk space and extra time.

To develop a backup strategy, consider the following questions:

• How long can the production database remain inoperable before business consequences become intolerable?
• What backup strategy is necessary to meet your availability requirements?
• Are backups archived in a safe, offsite location?
• Are backups tested to ensure that they are done properly?
• How quickly can backups be restored (including backups in offsite storage)?
• Have disaster recovery procedures been tested successfully?

Your backup strategy should answer all of these questions, and include procedures for successfully backing up and recovering your database. For information about implementing backup strategies using RMAN, review Oracle Database Backup and Recovery User’s Guide.

In addition, to ensure that you are prepared for a downgrade, review the downgrade chapter and complete any preparation steps you may need to prepare for your release.