Upgrade from Oracle Database 10.2.0.4 to 11.2.0.1

Just upgraded one of our databases from 10.2.0.4 to 11.2.0.1. The following outlines the major steps:

1. Install Oracle 11.2.0.1 software. Choose 'install database software only' option. Specify a location for Oracle Base that is required for Oracle 11g diagnostic framework        


2. Perform complete pre-upgrade checklist according to metalink note 870814.1, including:
1) Identify invalid objects and recompile them.  2) Resolve TIMESTAMP WITH TIMEZONE Datatype. Metalink note 815679.1 provides excellent explanation and solution on this. In my case I don't need to perform any action. 3) Update optimizer statistics, including dictonary and SYS schema 4) Run utlu112i.sql to identify issues and correct them, including free space in the tablespaces, size of some of the pools
3. !!Backup the database!!
 
4. Perform the upgrade with dbua
On the first try, I had issue and the upgrade aborted with ORA-0431 error and had to restore the database from the backup. The database uses AMM. However after increasing the sga_target from 700M to 1G, I was able to upgrade to the database successfully on the second try. 


5. Perform post-upgrade, including
1) Update some of the init.ora parameters, such as compatible, using memory_target, etc. 2) Update all the scripts, such as backup, start/stop scripts to reflect the new Oracle home