Patching OEM Grid Control Release 2

I have recently had the pleasure of patching two separate OEM Grid Control Release 2 installations and wanted to pass on what I found. It was not at all obvious how to apply the current Critical Patch Updates since Grid Control is a hodgepodge of different versions in different ORACLE_HOMEs. The following will detail what I believe are the proper patches and the order to apply them in.

The base release of Grid Control Release 2 is 10.2.0.1.0 and the installation creates three separate ORACLE_HOMEs. One for the database repository (db10g), one for the management server (oms10g) and one for the agent (agent10g).

The Oracle products include version 10.1.0.2.0 for the database and version 10.1.2.0.2 for the 10g Application Server. The following will list the steps and patches needed to bring Grid Control Release 2 up to the October 2006 CPU level:

1) Grid Control Release 2 is version 10.2.0.1.0, this is installed first. This will create three ORACLE_HOMEs. The default is to name the database repository db10g, the management server oms10g and the agent agent10g.

2) The next step is to patch all three ORACLE_HOMEs to Grid Control Release 10.2.0.2.0. This is done with patch 3731593.

3) Step 3 is to apply the 10.1.0.5.0 database patch set to the db10g and oms10g ORACLE_HOMEs.

4) Now the Critical Patch Update for database version 10.1.0.5.0 can be applied to the db10g ORACLE_HOME. This is patch 5490845.

5) Next the Critical Patch Update for Oracle Application Server 10.1.2.0.2 should be applied to the oms10g ORACLE_HOME. The patch number is 5483346.

6) No Critical Patch Updates need to be applied to the agent10g ORACLE_HOME. When the Grid Control patch was run it updated the OEM agent to 10.2.0.2.0
and there are no CPU patches for this version yet.