Check COMPATIBLE Parameter when Downgrading Oracle Database
If COMPATIBLE
has been changed after the upgrade, then it is
no longer possible to downgrade an Oracle Database.
If you have updated the COMPATIBLE
parameter to set the
compatibility level of your Oracle Database release to the current release, then you are
not able to downgrade to an earlier release. This issue occurs because new releases have
changes to the Data Dictionary, and can have other feature changes that prevent
downgrades.
To check the COMPATIBLE
parameter setting for your database
before you downgrade, enter the following command:
SQL> SELECT name, value, description FROM v$parameter WHERE name =
‘compatible’;
Note:
New installations of Oracle Database 23ai Release Update 23.6 automatically update
the COMPATIBLE
parameter setting to 23.6.
For Oracle ASM disk groups, if you changed the compatible.asm
parameter after the upgrade to the upgraded release value, then when you downgrade
to the earlier release, you cannot mount your Oracle ASM disk groups. The value for
compatible.asm
sets the minimum Oracle ASM release that can
mount a disk group.
As part of your downgrade, you must create a new disk group to your downgraded release level, and restore data to that downgraded compatibility ASM disk group.
Parent topic: Downgrading Oracle Database to an Earlier Release