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 1-1 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