Patching Oracle with Patch Set best practices
Patch Set is an Oracle major patch bundle that provides bug fixes only. It is a mechanism for delivering fully tested and integrated product fixes that do not include new functionality. All of the fixes in the Patch Set have been tested and are certified to work with each other.
Oracle Patch Set can be applied on the base release version or on any of the earlier Patch Sets of the same base release. You can apply it not only to Oracle database but to the following list of Oracle installations:
- Oracle Database
- Oracle Real Application Clusters
- Oracle Database Client
- Oracle Database Companion CD
- Oracle Clusterware
- Oracle Database Vault
Based on Oracle, a Patch Set does not require you to certify applications or tools against the server because it includes only low impact patches. Nevertheless, based on my experience most of application vendors do certify Oracle Patch Sets. Besides in my long Oracle experience after the patching I faced sometimes different application issues like performance degradation, new errors, changed result sets, even SQL hangs. Therefore, I recommend to test applications thoroughly with the latest patch applied to avoid all those nasty things. Additionally, I always collect application and database performance baseline statistics before the patching to compare it with the figures after it.
I strongly recommend creating a backup of the Oracle Inventory, Oracle home binaries and your database before you install the Patch Set.
I count about 4 hours for Patchset installation. That does not include the database backup though. Below are major steps:
– Check database backup and perform clean shutdown of a DB instance
– Backup binaries
– Upgrade binaries
– Do postinstallation tasks (run catupgrade, compile invalid object etc)
– Restart database and conduct basic system test
Below are the latest Patch sets for major Oracle releases available at the moment
184.108.40.206.0 - Patchset #1 (for Oracle 11g Base Release 220.127.116.11.0) 10.2.0.5.0 - Patchset #4 (for Oracle 10gR2 Base Release 10.2.0.1.0) 10.1.0.5.0 - Patchset #3 (for Oracle 10g Base Release 10.1.0.2.0) 18.104.22.168 - Patchset #7 (for Oracle 9iR2 Base Release 22.214.171.124) 126.96.36.199 - Patchset #4 (for Oracle 9i Base Release 188.8.131.52)
Note: Do not mix up Patch Set and Patch Set Update (PSU). PSU is a minor bug fix bundle that is applied on top of the Patch Set. Therefore, my general recommendation is applying the latest Patchset and then the latest PSU. Read my article about PSU patching: PSU simplify Oracle patching.