Overview of RDS for Oracle engine upgrades - Amazon Relational Database Service
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Overview of RDS for Oracle engine upgrades

Before upgrading your RDS for Oracle DB instance, familiarize yourself with the following concepts.

Major and minor version upgrades

Major versions are major releases of Oracle Database that occur every 1-2 years. Examples of major releases are Oracle Database 19c and Oracle Database 21c.

Minor versions, which are also called Release Updates (RUs), are typically released by Oracle every quarter. Minor versions contain small feature enhancements and bug fixes. Examples of minor versions are and For more information, see Release notes for Amazon Relational Database Service (Amazon RDS) for Oracle.

RDS for Oracle supports the following upgrades to a DB instance.

Upgrade type Application compatibility Upgrade methods Sample upgrade path
Major version A major version upgrade can introduce changes that aren't compatible with existing applications. Manual only From Oracle Database 19c to Oracle Database 21c
Minor version A minor version upgrade includes only changes that are backward-compatible with existing applications. Automatic or manual From to

When you upgrade your DB engine, an outage occurs. The duration of the outage depends on your engine version and DB instance size.

Make sure that you thoroughly test any upgrade to verify that your applications work correctly before applying the upgrade to your production databases. For more information, see Testing an Oracle DB upgrade.

Expected support dates for RDS for Oracle major releases

RDS for Oracle major versions remain available at least until the end of support date for the corresponding Oracle Database release version. You can use the following dates to plan your testing and upgrade cycles. These dates represent the earliest date that an upgrade to a newer version might be required. If Amazon extends support for an RDS for Oracle version for longer than originally stated, we plan to update this table to reflect the later date.

Oracle Database major release version Expected date for upgrading to a newer version

Oracle Database 19c

April 30, 2026 with BYOL Premier Support (fees waived for Extended Support)

April 30, 2027 with BYOL Extended Support (extra cost) or an Unlimited License Agreement

April 30, 2027 with License Included (LI)

Oracle Database 21c

April 30, 2025 (not available for Extended Support)

Before we ask you to upgrade to a newer major version, we remind you at least 12 months in advance. We detail the upgrade process, including the timing of important milestones, the impact on your DB instances, and recommended actions. You should thoroughly test your applications with new RDS for Oracle versions before you upgrade to a major version.

After this advance notification period, an automatic upgrade to the subsequent major version might be applied to any RDS for Oracle DB instance still running the older version. If so, the upgrade is started during scheduled maintenance windows.

For more information, see Release Schedule of Current Database Releases in My Oracle Support.

Oracle engine version management

With DB engine version management, you control when and how the database engine is patched and upgraded. You get the flexibility to maintain compatibility with database engine patch versions. You can also test new patch versions of RDS for Oracle to ensure they work with your application before deploying them in production. In addition, you upgrade the versions on your own terms and timelines.


Amazon RDS periodically aggregates official Oracle database patches using an Amazon RDS-specific DB engine version. To see a list of which Oracle patches are contained in an Amazon RDS Oracle-specific engine version, go to Amazon RDS for Oracle Release Notes.

Automatic snapshots during engine upgrades

During upgrades of an Oracle DB instance, snapshots offer protection against upgrade issues. If the backup retention period for your DB instance is greater than 0, Amazon RDS takes the following DB snapshots during the upgrade:

  1. A snapshot of the DB instance before any upgrade changes have been made. If the upgrade fails, you can restore this snapshot to create a DB instance running the old version.

  2. A snapshot of the DB instance after the upgrade completes.


To change your backup retention period, see Modifying an Amazon RDS DB instance.

After an upgrade, you can't revert to the previous engine version. However, you can create a new Oracle DB instance by restoring the pre-upgrade snapshot.

Oracle upgrades in a Multi-AZ deployment

If your DB instance is in a Multi-AZ deployment, Amazon RDS upgrades both the primary and standby replicas. If no operating system updates are required, the primary and standby upgrades occur simultaneously. The instances are not available until the upgrade completes.

If operating system updates are required in a Multi-AZ deployment, Amazon RDS applies the updates when you request the database upgrade. Amazon RDS performs the following steps:

  1. Updates the operating system on the current standby DB instance.

  2. Fails over the primary DB instance to the standby DB instance.

  3. Upgrades the database version on the new primary DB instance, which was formerly the standby instance. The primary database is unavailable during the upgrade.

  4. Updates the operating system on the new standby DB instance, which was formerly the primary DB instance.

  5. Upgrades the database version on the new standby DB instance.

  6. Fails over the new primary DB instance back to the original primary DB instance, and the new standby DB instance back to the original standby DB instance. Thus, Amazon RDS returns the replication configuration to its original state.

Oracle upgrades of read replicas

The Oracle DB engine version of the source DB instance and all of its read replicas must be the same. Amazon RDS performs the upgrade in the following stages:

  1. Upgrades the source DB instance. The read replicas are available during this stage.

  2. Upgrades the read replicas in parallel, regardless of the replica maintenance windows. The source DB is available during this stage.

For major version upgrades of cross-Region read replicas, Amazon RDS performs additional actions:

  • Generates an option group for the target version automatically

  • Copies all options and option settings from the original option group to the new option group

  • Associates the upgraded cross-Region read replica with the new option group