dbawiki

For versions below 12.2.0.1

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

how to apply patch in oracle

What patches are installed?

Display the Patch inventory

$ORACLE_HOME/OPatch/opatch lsinventory

Display just the patches

$ORACLE_HOME/OPatch/opatch lspatches

From SQL*Plus in version 11

dba_registry_history is a view on registry$history

col action_time for a21
col action      for a15
col namespace   for a15
col version     for a15
col comments    for a80 wrap
select action_time, action, namespace, version, id, comments from dba_registry_history order by 1;

From 12.1.0.1 onwards

Reference: Datapatch User Guide (Doc ID 2680521.1)

Patching is now no longer performed inline. It is always done in a new ORACLE_HOME. So the databases do not need to be stopped until each one is moved to the new home.
When the database is restarted in the new home, $ORACLE_HOME/OPatch/datapatch must be run to apply the SQL fixes.

From SQL*Plus in version 12

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

Now things are getting more interesting…