Upgrading the Oracle DB engine - Amazon Relational Database Service

Upgrading the Oracle DB engine

When Amazon RDS supports a new version of Oracle, you can upgrade your DB instances to the new version. For information about which Oracle versions are available on Amazon RDS, see Amazon RDS for Oracle Release Notes.

Important

RDS for Oracle Database 11g is deprecated. If you maintain Oracle Database 11g snapshots, you can upgrade them to a later release. For more information, see Upgrading an Oracle DB snapshot.

Oracle major version upgrades

To perform a major version upgrade, modify the DB instance manually. Major version upgrades don't occur automatically.

Supported versions for major upgrades

Amazon RDS supports the following major version upgrades.

Current version Upgrade supported

19.0.0.0 using the CDB architecture

21.0.0.0

12.2.0.1

19.0.0.0 using the non-CDB architecture

12.1.0.2

19.0.0.0 using the non-CDB architecture

12.2.0.1

A major version upgrade of Oracle Database must upgrade to a Release Update (RU) that was released in the same month or later. Major version downgrades aren't supported for any Oracle Database versions.

Supported instance classes for major upgrades

Your current Oracle DB instance might run on a DB instance class that isn't supported for the version to which you are upgrading. In this case, before you upgrade, migrate the DB instance to a supported DB instance class. For more information about the supported DB instance classes for each version and edition of Amazon RDS for Oracle, see DB instance classes.

Gathering statistics before major upgrades

Before you perform a major version upgrade, Oracle recommends that you gather optimizer statistics on the DB instance that you are upgrading. This action can reduce DB instance downtime during the upgrade.

To gather optimizer statistics, connect to the DB instance as the master user, and run the DBMS_STATS.GATHER_DICTIONARY_STATS procedure, as in the following example.

EXEC DBMS_STATS.GATHER_DICTIONARY_STATS;

For more information, see Gathering optimizer statistics to decrease Oracle database downtime in the Oracle documentation.

Allowing major upgrades

A major engine version upgrade might be incompatible with your application. The upgrade is irreversible. If you specify a major version for the EngineVersion parameter that is different from the current major version, you must allow major version upgrades.

If you upgrade a major version using the CLI command modify-db-instance, specify --allow-major-version-upgrade. This setting isn't persistent, so you must specify --allow-major-version-upgrade whenever you perform a major upgrade. This parameter has no impact on upgrades of minor engine versions. For more information, see Upgrading a DB instance engine version.

If you upgrade a major version using the console, you don't need to choose an option to allow the upgrade. Instead, the console displays a warning that major upgrades are irreversible.

Oracle minor version upgrades

A minor version upgrade applies an Oracle Database Patch Set Update (PSU) or Release Update (RU) in a major version.

An Amazon RDS for Oracle DB instance is scheduled to be upgraded automatically during its next maintenance window when it meets the following conditions:

  • The DB instance has the Auto minor version upgrade option enabled.

  • The DB instance is not running the latest minor DB engine version.

The DB instance is upgraded to the latest quarterly PSU or RU four to six weeks after it is made available by Amazon RDS for Oracle. For more information about PSUs and RUs, see Amazon RDS for Oracle Release Notes.

The following minor version upgrades aren't supported.

Current version Upgrade not supported

12.1.0.2.v6

12.1.0.2.v7

12.1.0.2.v5

12.1.0.2.v7

12.1.0.2.v5

12.1.0.2.v6

Note

Minor version downgrades aren't supported.

Oracle SE2 upgrade paths

The following table shows supported upgrade paths to Standard Edition Two (SE2). For more information about the License Included and Bring Your Own License (BYOL) models, see Oracle licensing options.

Your existing configuration Supported SE2 configuration

12.2.0.1 SE2, BYOL

12.2.0.1 SE2, BYOL or License Included

12.1.0.2 SE2, BYOL

12.2.0.1 SE2, BYOL or License Included

12.1.0.2 SE2, BYOL or License Included

To upgrade from your existing configuration to a supported SE2 configuration, use a supported upgrade path. For more information, see Oracle major version upgrades.

Preparing for the automatic upgrade of Oracle Database 12c

Oracle Database 12c is on a deprecation path. As explained in Oracle Database 12c with Amazon RDS, Amazon RDS plans to begin automatically upgrading Oracle Database 12c DB instances to Oracle Database 19c. The automatic upgrades are scheduled to begin on the following dates:

  • April 1, 2022 for Oracle Database 12c Release 2 (12.2.0.1)

  • August 1, 2022 for Oracle Database 12c Release 1 (12.1.0.2)

The automatic upgrades are not guaranteed to occur in your maintenance window. All Oracle Database 12c DB instances, including reserved instances, will move to the latest available Release Update (RU).

Before the automatic upgrades begin, we highly recommend that you upgrade your existing Oracle Database 12c DB instances to Oracle Database 19c manually. In this way, you can validate that your applications work correctly. To avoid the automatic upgrade, use one of the following strategies before the beginning of the automatic upgrades.

Upgrade your Oracle Database 12c Release 2 (12.2) DB instance

Before you upgrade your Oracle Database 12c DB instance to Oracle Database 19c, consider the following:

  • Your SQL statements might perform differently after the upgrade. If so, you can use the OPTIMIZER_FEATURES_ENABLE parameter to retain the behavior of the Oracle Database 12c optimizer. For more information, see Influencing the Optimizer in the Oracle Database documentation.

  • If you have Extended Support for Oracle Database 12c on the BYOL model, consider the implications. In this case, you must have Extended Support agreements from Oracle Support for Oracle Database 19c. For details on licensing and support requirements for BYOL, see Amazon RDS for Oracle FAQs.

Upgrade your Oracle Database 12c DB snapshots

You can upgrade your existing snapshots to Oracle Database 19c, and then restore them. For more information, see Upgrading an Oracle DB snapshot.

If you plan to upgrade Oracle Database 12c using snapshots, the planned deadlines to avoid the automatic upgrade are listed in Oracle Database 12c with Amazon RDS.

Downgrade your Oracle Database 12c Release 2 (12.2) DB instance

You might decide not to upgrade your Oracle Database 12c Release 2 (12.2) DB instances to Oracle Database 19c. In this case, you can downgrade your instance to Oracle Database Release 1 (12.1.0.2). Use any of the following techniques:

  • Oracle Data Pump

  • AWS Database Migration Service (DMS)

  • Any supported logical replication tool

For more information about import options, see Importing data into Oracle on Amazon RDS.