Main problem is that many of this actions require db downtime. Here is small trick to achive that in best possible way.
The solution
Example: If you want to install PSU4 and PSU9 on Oracle 10.2.0.4 version follow these steps- Shutdown database (backup!?).
- Apply PSU4 (Base PSU)
- Apply PSU9
- Startup the database
- Run
catbundle.sql psu apply --- (for PSU4)
- Run
catbundle.sql opsu apply --- (for PSU9)
The End
More can be read on Oracle Support argumentation:- 605795.1 - Introduction To Oracle Database catbundle.sql
- 834644.1 - catbundle.sql - FAQ
Cheers!