Out-of-place upgrade

Hello Hemss,

I am trying to do an in-place-upgrade (replacing the old Oracle software completely because our test servers have only very little space). When you want to perform an out-of-place upgrade, things are more simple, but you need the disk space for a new Oracle home (about 6 GB on Linux-x64 in my case). Essentially, the steps are:

1. You can keep the production database online during the next steps
2. Install the new 11.2.0.2.0 into a new Oracle Home (an Oracle software directory which does not exist yet). Only install the software. 
3. Apply any post-11.2.0.2.0 patches if available and needed
4. Schedule a maintenance window with your users
5. Put the original database(s) in MOUNT mode (SHUTDOWN IMMEDIATE followed by STARTUP MOUNT)
6. Perform a FULL backup of both database and old Oracle home, just to be on the safe side.
7. Set your enviromnent: ORACLE_HOME and ORACLE_BASE should point to your NEW installation, ORACLE_SID to your production database.
8. Start netca to create a new LISTENER for your new software installation (you might want to use a different port than your previous installation in case you need to run both at the same time)
9. Start dbua from the new Oracle Home and follow the on-screen instructions. You can either create an updated copy of the database (needs more disk space but you can easily switch back to your orginal DB), or you change the database to fit your new Oracle version (needs less space, but you need to run the scripts to downgrade to the old release if you need to go back)

So, as long as you have plenty of disk space, things are not that difficult at all. Of course, you should always read the release notes and the full installation guides for the new version because there might be new features or behaviours that affect your database. It is also highly advisable to test this on a completely different machine first.

You can find the complete upgrade guide here: http://download.oracle.com/docs/cd/E11882_01/server.112/e17222/toc.htm