There may be several circumstances that cause OPatch to fail in the patch apply task. The DBA must always read the instructions and make sure they are fully understood and the prerequisites are fully met. This reduces the number of possible failures during the patch apply process.

Let's assume a scenario; the DBA tries to apply a patch but it is only partially applied, OPatch works in an idempotent way, that is, the steps required by OPatch to apply a patch are executed only once. It doesn't matter how many times the user manually restarts the patch apply task. So if the user wants to rollback a partially applied patch the only way to start the rollback procedure is by first finishing the started patch apply task.