1. Using AutoUpgrade to Upgrade and Convert Non-CDBs to a PDB with the Same Operating System
  2. Checking Compatibility Before Upgrading Oracle Database

1 Checking Compatibility Before Upgrading Oracle Database

Check the Oracle Database server upgrade compatibility matrix before upgrading the Oracle Database.

Oracle Database Releases That Support Direct Upgrade

Review the supported options for direct upgrades to Oracle Database 21c.

You can perform a direct upgrade to the new release from the following releases:

  • 19c
  • 18c
  • 12c Release 2 (12.2)

The path that you must take to upgrade to the latest Oracle Database release depends on the release number of your current database.

If your current Oracle Database is a release earlier than release 12.2, then you cannot directly upgrade your Oracle Database to the latest release. In this case, you are required to upgrade to an intermediate release before upgrading to Oracle Database 21c.

If you cannot carry out a direct upgrade, then carry out an upgrade to the most recent release where direct upgrades are supported.

Note:

For any multi-step upgrade, if you must carry out two upgrades to upgrade to the current release, then you must run the preupgrade script twice: First, complete an upgrade to an intermediate upgrade release that is supported for direct upgrade to the target upgrade release. Second, complete the upgrade for the target upgrade release.

For example, if the database from which you are upgrading is running Oracle Database 11g Release 2 (11.2) then to upgrade to Oracle Database 21c, follow these steps:

  1. Upgrade Release 11.2 to release 12.2, using the instructions in Oracle Database Upgrade Guide 12c Release 2 (12.2), including running the preupgrade script for 12.2.

  2. Upgrade Oracle Database 12c Release 2 (12.2) directly to Oracle Database 21c. Use the instructions in this book, Oracle Database Upgrade Guide, including running the preupgrade script for Oracle Database 21c.

The following table shows the required upgrade path for each release of Oracle Database. Use the upgrade path and the specified documentation to perform an intermediate upgrade of your database before fully upgrading to Oracle Database 21c.

Table 1-1 Examples of Upgrade Paths for Oracle Database 21c

Current Release Upgrade Options

19 (all releases), 18 (all releases), 12.2.0.1

Direct upgrade is supported. Perform the upgrade using the current Oracle Database Upgrade Guide, which is this guide.

12.1.0.2.

12.1.0.1

11.2.0.1, 11.2.0.2, 11.2.0.3, 11.2.0.4

11.1.0.6, 11.1.0.7

10.2 or earlier releases

Direct upgrade to Oracle Database 21c is not supported.

Solution: Upgrade to an intermediate Oracle Database release that can be directly upgraded to the current release. Upgrade Oracle Database releases that are not supported for direct upgrade in this release to an intermediate Oracle Database release that is supported for direct upgrade.

When upgrading to an intermediate Oracle Database release, follow the instructions in the intermediate release documentation, including running the preupgrade scripts for that intermediate release. After you complete an upgrade to the intermediate release Oracle Database, you can upgrade the intermediate release database to the current Oracle Database release.

This restriction does not apply if you use Oracle Data Pump export/import to migrate data to the new release.

For example:

  • Releases 12.1.0.1, 12.1.0.2, 11.2.0.3, 11.2.0.4: Upgrade to Oracle Database 12c Release 2 (12.2), and then upgrade to Oracle Database 21c.

  • Releases 10.2.0.2, 10.2.0.3, 10.2.0.4, 10.2.0.5 or 10.1.0.5: Upgrade to release 11.2.0.3 or 12.1, and then to 12.2, and then to Oracle Database 21c.

Note: Always update to the most recent intermediate release to which you can upgrade directly. Your case can be different from that of the examples provided here.

Parent topic: Checking Compatibility Before Upgrading Oracle Database

Checking the Compatibility Level of Oracle Database

Use this SQL query to find the COMPATIBLE initialization parameter value set for your database. 

SQL> SELECT name, value FROM v$parameter
         WHERE name = 'compatible';

Values for the COMPATIBLE Initialization Parameter in Oracle Database

Review to find the default and minimum values for the COMPATIBLE initialization parameter for Oracle Database 21c.

Default and Minimum COMPATIBLE Parameter Values

The minimum supported release for direct upgrade to Oracle Database 21c is Oracle Database 12c Release 2 (12.2). The minimum COMPATIBLE parameter value for Oracle Database 21c is 12.2.0. The default value for the COMPATIBLE parameter is 21.0.0. Before you use a direct upgrade to Oracle Database 21c, you must set the COMPATIBLE parameter on your source Oracle Database release to at least 12.2.0.

The COMPATIBLE parameter should not be changed for a Release Update (RU) or a Release Update Revision (RUR), either for CDB or Non-CDB instances. The following table lists the default and minimum values for the COMPATIBLE parameter in Oracle Database 21c, compared to earlier releases supported for direct upgrade:

Caution:

After the COMPATIBLE parameter is increased, database downgrade is not possible.

When you plug in an earlier release PDB to a later release CDB where COMPATIBLE is set to a later release than the earlier release PDB, and you upgrade the PDB by using an unplug/plug/upgrade procedure, the COMPATIBILE setting of the upgraded PDB is automatically increased to the COMPATIBLE setting of the later release CDB.

Do not alter the COMPATIBLE parameter to a value other than a default release value. Use only one of the default values listed in the following table.

Table 1-2 The COMPATIBLE Initialization Parameter

Oracle Database Release Default Value Minimum Value
Oracle Database 21c

21.0.0

12.2.0

Oracle Database 19c

19.0.0

11.2.0

Oracle Database 18c

18.0.0

11.2.0

Oracle Database 12c Release 2 (12.2)

12.2.0

11.2.0