useful database upgrade notes

I was searching for useful upgrade notes and i found the following so i decided to share it:


Minimizing Downtime During Production Upgrade [ID 478308.1]
Master Note For Oracle Database Upgrades and Migrations [ID 1152016.1]
Different Upgrade Methods For Upgrading Your Database [ID 419550.1]
Migration of Oracle Database Instances Across OS Platforms[ID 733205.1]
Oracle® Database Upgrade Guide:
10g Release 2 (10.2)
http://docs.oracle.com/cd/B19306_01/server.102/b14238/upgrade.htm#i1011372