Oracle updating

In all other cases, you must modify the DB instance manually to perform a minor version upgrade. The time for the outage varies based on your engine version and the size of your DB instance.For information about what Oracle versions are available on Amazon RDS, see Oracle Database Engine Release Notes.Note Amazon RDS only takes DB snapshots if you have set the backup retention period for your DB instance to a number greater than 0.To change your backup retention period, see Modifying a DB Instance Running the Oracle Database Engine.If your DB instance is in a Multi-AZ deployment, both the primary and standby replicas are upgraded.If no operating system updates are required, the primary and standby DB instances are upgraded at the same time, and you experience an outage until the upgrade is complete.

Before you perform a major version upgrade, Oracle recommends that you gather optimizer statistics on the DB instance that you are upgrading.Amazon RDS takes two DB snapshots during the upgrade process.The first DB snapshot is of the DB instance before any upgrade changes have been made.If your DB instance is in a Multi-AZ deployment, and operating system updates are required, the operating system updates are applied when you request the database upgrade.In this case, the operating system is updated on the standby DB instance, and the standby DB instance is upgraded.