All patches that are installed with Oracle’s OPatch Utility (Oracle’s Interim Patch Installer) can be listed by invoking the opatch command with the lsinventory option. Here is an example:
$ cd $ORACLE_HOME/OPatch
$ opatch lsinventory
Invoking OPatch 10.2.0.1.0
Oracle interim Patch Installer version 10.2.0.1.0
Copyright (c) 2005, Oracle Corporation. All rights reserved..
…
Installed Top-level Products (1):
Oracle Database 10g 10.2.0.1.0
There are 1 products installed in this Oracle Home.
There are no Interim patches installed in this Oracle Home.
OPatch succeeded.
Another Method using SYS.REGISTRY$HISTORY Table
Since January 2006, contains 1 row for most recent CPU patch applied
Semi-reliable method for determining if CPU patch is applied
SELECT comments, action_time, id “PATCH_NUMBER”, version
FROM sys.registry$history
WHERE action = ‘CPU’;
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