Patching

On bog standard iron, this was a fairly simple procedure. Download the patch, stop the databases and listeners and opatch the ORACLE_HOME.
a word about the different patching terminology;overlay, merge, bundle etc..

What patches are installed?

From command line

$ORACLE_HOME/OPatch/opatch lspatches

Version 11

select action, namespace, version, id, comments from dba_registry_history;

Version 12

select extract(sys.dbms_qpatch.get_opatch_list,'//patchDescription|//appliedDate|//patchID') from dual;

Now things are getting more interesting...

• Patching Oracle Database Appliance (ODA)
• Patching Exadata