Upgradation – Patch set apply Upgradation will change the database minor release from one version to another. Ex: major.minor.build.revision.release 10.2.0.1.0 — 10.2.0.5.0 11.2.0.1.0 — 10.2.0.4.0 Go to oracle website — Choose type as patchset — Search and download. Ex: p120205_linux_x86.zip ~1000 MB Why do we need to do an upgrade? When there is a product bug, we need to do an upgrade, since there is no proper solution, there may be a workaround. Ex: ORA-006000 – internal error ORA – 7445 Pre-upgrade checks and tasks Stop listener Down the database $ echo $ORACLE_HOME – Note down it Shared_pool, Large_pool & jave_pool – should be > 128 MB System, sysAux, Undo,…