I am new to patching of oracle database, i need to patch up my base version of oracle database 10.2.0.1 to 10.2.0.4.
Kinldy provide me a good doc or link for the same.
If you are going to patch at all, patch to the latest version 10.2.0.5
Pl see this MOS Doc
10.2.0.5 Patch Set - Availability and Known Issues [ID 1087991.1]
Directions for applying the 10.2.0.5 patch are included in the README of the patch.
On top of 10.2.0.5, it is advisable to apply the latest PSU (10.2.0.5.9) - pl see this MOS Doc
Quick Reference to RDBMS Database Patchset Patch Numbers [ID 753736.1]
This will need to be applied after 10.2.0.5 - again, the instructions are in the README.
Pl also be aware that 10gR2 is de-supported - you should be upgrading to 11gR2