Everyone that I’ve worked with knows that I don’t like patching (and sometimes I try to imagine who does), but they are necessary to corrects bugs and improve the Oracle software stability.
When you have a single node server with one database, the patch planing is no brainer but when you have a RAC with multiple nodes, different Oracle homes and so on, the planning and preparations start to get more complex and it is easy to miss or overlook a step in the planning which can lead to issues during your patching.
So to help me with all that I use oplan. Oplan is a tool which comes with along OPatch and you can get its latest version in patch 6880880
More informations on oplan can be found here: Oracle Software Patching with OPLAN (Doc ID 1306814.1)
OK, so what do I used it most for?
Generating the apply patching steps, which are very in handy:
$ORACLE_HOME/OPatch/oplan/oplan generateApplySteps <bundle patch location>
And my favorite, rollback steps, which I have done more times that I would like to admit:
$ORACLE_HOME/OPatch/oplan/oplan generateRollbackSteps <bundle patch location>
Also as rollback, I do tar of the oracle binaries being patched prior as there times even the rollback did not work :-/
Both files will be created under the directory below and you will see an html and text files.
This process is to help you organise your steps, read it through prior executing to make sure it makes sense in your environment
Oplan has its limitations, from the Oracle note which I mentioned above:
Data Guard configurations are not supported. OPlan can be used to create patch plans for Oracle home's running Oracle Data Guard configurations, but OPlan does not consider such an environment usable as 'Data Guard Standby-First Patch Apply' alternative. See the following for additional information on 'Data Guard Standby-First Patch Apply' <Document 1265700.1> Oracle Patch Assurance - Data Guard Standby-First Patch Apply Shared Oracle Home Configurations are not supported. Single Instance Databases running in the same configuration are not supported
Even so I would still use it as it generates a plan based on your target environment adding more information that you would need to do manually if you were only to read the README files from the patching
Hope it helps.
Thanks and until next time