Our business is on the way of migrating the databases. Before migrating the databases, we need to evaluate whether we need to apply CPU or PSU patches after migration.
If we are positive on applying CPU patches, then we will migrate the oracle_homes as well, as we have been applying CPU patches after every release.
In case if we are positive upon PSU patches, then we will be migrating only the databases.
So with this scenario, we need to evaluate whether we need CPU or PSU. I did a basic analysis and found that PSU contains the CPU plus non-security updates. Therefore applying PSU is beneficial. Also we cannot mixmatch the patches i.e. if we are applying CPU, then we have to apply only CPU patches and if we are applying PSU then we have to apply only PSU patches. However we still need to know further details which could be captured from the answers to below questions.
1. What are the risks and impacts of applying the patches.
2. When Oracle releases both CPU and PSU, on what basis can we evaluate whether we need CPU/PSU when we are applying for the 1st time.
3. If, after a period of time after applying patches, if we encounter any bugs and Oracle recommeds to apply a bug fix, what will be the implication that will be encountered if we have to apply on top of CPU or PSU patches.
4. Will any situation arise where we need to apply a CPU patch, when we already have been applying PSU patch. If so do we have to rollback all the PSU patches or only the
5. Do we need to install new oracle_home each time we are applying PSU patch
6. Are there any ways we can reduce downtime. Are these hot patches. We have reduced our downtime while applying CPU patches by applying through OEM. How do we knoe whether they are hot or cold patches
These are some of the questions. Maybe later on i may get more questions. But I would like to get a clear idea.
Note: I had to write this elaborately, so that I can make myself clear on the scenario and also to avoid redundancy while posting messages.