When working with shared Oracle Homes you environment will look like this:
- One ORACLE_HOME in which installed the most recent release of Oracle DB, for instance 188.8.131.52
- Several Database Instances running on the Oracle Software installed
If we want to apply a Patch to an environment like this we need to follow a scenario like this:
- Download the Patch manually from MOS
- Study the documentation
- Check if the proper version of OPatch is available and upgrade if necessary
- Clone the current ORACLE_HOME (you might be using a Golden Image in the EM Software Library for this)
- Install the Patch on the cloned ORACLE_HOME
- Stop database per database and copy necessary files (<oracle_home>/dbs/…)
- Modify /etc/oratab to modify the path to the cloned ORACLE_HOME
- Startup the database in the clone ORACLE_HOME
- Execute necessary sql scripts
10. Check and document
Indeed an intensive and error prone scenario.
EM 10.2.0.5 and 11.1 provided us with a Patching procedure that was unable to cover this scenario.
EM 12c however now provide us with a procedure that takes care of this “Out-of-place” Patching procedure.
Starting with the support of Single Instances and RAC on Exadata, the support for RAC on clustered Servers is soon to follow (obviously as this is a more or less same procedure as the support for Exadata).
By this IT departments are able to perform a robust, complete patching procedure in which databases will be patched one by one with a minimum of down time.