Enterprise environments frequently require this specific patch level for several reasons:
You cannot install 10.2.0.5 directly. You must first install the base 10g Release 2 software (10.2.0.1 or 10.2.0.4 depending on OS) and then apply the 10.2.0.5 patch set to that existing Oracle Home. Support Status Database 10gR2 10.2.0.5 Certified with E-Business Suite oracle database 10g release 2 10205 download new exclusive
It represents the pinnacle of 10g stability, offering the fewest memory leaks and optimal query optimizer performance for that generation. oracle database 10g release 2 10205 download new exclusive
Before downloading and installing Oracle Database 10g Release 2 (10.2.0.5), ensure that your system meets the following requirements: oracle database 10g release 2 10205 download new exclusive
After your "new exclusive" download, immediately apply:
Complete Guide to Downloading Oracle Database 10g Release 2 (10.2.0.5)