Version needed to apply patch
It seems that in order to use the latest version of opatch, OUI needs to be at version 10.1.0.2. Our databases are version 18.104.22.168 and OUI is 2.2. We're currently preparing to apply CPU (Oct2006). CPU notes state that the opatch utility must be at least version 22.214.171.124.55. We're currently using 126.96.36.199.52.
I always recommend downloading the latest version of opatch prior to applying any patches. As far as I know, opatch does not use the OUI, although it does read and update the global inventory. Opatch is a Perl-based utility that is used to apply CPUs and one-off patches. The OUI is used for installing Oracle software and performing upgrades or migrations.
Oracle's Metalink Web site contains a good document about opatch worth reviewing (Doc ID #224346.1 "Where can I find the latest version of opatch?"). Download the latest release of opatch and follow the readme file for information on how to install and run opatch.
This was first published in January 2007