Oracle Database Discussions

We are in the process of upgrading our DB's from 10.2.0.2.0/11.1.0.7.0 to 11.2.0.3.0.

Currently, we have a mix of Oracle 10.2 Clients and 11.1.0.6.0 and 11.1.0.7.0 on Windows XP/7, Server 2003/2008 Terminal Servers.

DB's are on AIX exclusively.

The question, is age old.

Which client is better a Custom client via response file vs. Instant Client.

With the knowledge that some clients still need to access the 10.2 (Production ERP system), but looking ahead for patches, upgrades, etc.

We know that some require (because of our applications) ODBC connections - ie ODBC Driver.

So Custom - and what's the bare minimum for terminals vs. instant client?

How are you, other deploying? We do not have imaging? or App Deployment, or VDI (yes, I know, why not), but moving on.

Powershell?

Batches/Scripts?

App Deployment? - Symantec, BigFix, ZENworks, MS SCCM/MOM, etc.

Manual?

Combination?

How are you addressing the second, third, etc. ORACLE_HOME?

Second drive - So some are currently installed on C:\, some D:\, etc. based on available disk space (yes, adds to the challenge).

Steps, I'm thinking here are.

1.) Create folder say C:\ORACLE_BKUP
2.) Copy *.ora (TNSNAMES.ORA, LISTENER.ORA -if running a local XE copy, and SQLNET.ORA) from ORACLE_HOME\network\admin\*.ora to C:\ORACLE_BKUP
3.) Have a remove 10g silent/resp
4.) Have a remove 11gR1 (11.1.0.6.0 and 11.0.7.0) silent/resp
5.) Backup to C:\ORACLE_BKUP via TAR/ZIP C:\ORACLE, C:\Program Files\Oracle, and HKLM\Software\ORACLE via regsvr32 export.
6.) Rename C:\Oracle\10g...11g\bin to c:\oracle\10g...11g\bin_old (needed for next step).
7.) Delete c:\Oracle, c:\Program Files\Oracle, HKLM\Software\Oracle and remove c:\Oracle\10g...11g\bin from PATH
8.) Install 11.2.0.3.0 (client custom or instant client) via silent/response file
9.) Copy the *.ora files from c:\ORACLE_BACKUP back to c:\ORACLE\11GR2\network\admin
10.) Have to possibly manuallly or via regsvr32 import re-create ODBC connections (w/o screwing up existng connections to SQL, etc.)
11.) Test TNSPING/SQLPLUS to make sure can connect.
12.) Then test applications.

Sound logical?

The question is which client?
If Custom, minimum install - ODBC Driver, but anything else?

Thanks in advance for you comments!