DBA_REGISTRY_HISTORY

DBA_REGISTRY_HISTORY provides information about upgrades, downgrades, and critical patch updates that have been performed on the database.

Column	Datatype	Description
`ACTION_TIME`	`TIMESTAMP(6)`	The time the upgrade, downgrade, or patch action was completed
`ACTION`	`VARCHAR2(30)`	The specific action (for example, UPGRADE or DOWNGRADE)
`NAMESPACE`	`VARCHAR2(30)`	The namespace of the components affected (for example, SERVER)
`VERSION`	`VARCHAR2(30)`	The version number of the server (for example, 10.2.0.1.0)
`ID`	`NUMBER`	The identification number of the Critical Patch Update
`COMMENTS`	`VARCHAR2(255)`	Additional comments about the action taken