RU/RUR Update/Revision
From release 12.2.0.1, “Release Update” ( RU) and ” Release Update Revision” ( RUR) are released, which replace the legacy PSUs and Proactive Bundle ( PB ) Patches.
From release 18 onwards, the terms ‘Update‘ and ‘Revision‘ are used instead of “Release Update” ( RU ) and ” Release Update Revision”( RUR ) in 12.2.0.1.
Oracle release pattern of Updates and Releases

Updates and Revisions Patching Path

The patching path is either :
- Vertically upward
- Progressive diagonal
- Progressive straight.
From an Update, the patching direction should be to either its 2 Revisions, released in consecutive quarters, OR the next quarter’s Update. There is no moving backward or vertical down.
If database is at Update 18.3.0 at the moment, the possible patching path could be :
Update 18.3.0 -> Revisions 18.3.1 , 18.3.2, 18.4.1 and so on or Update 18.3.0 -> Updates 18.4.0 , 18.5.0 and so on
Below patching path is NOT supported, because backward patching is non-cumulative. There is no moving back to earlier Release’s Updates and Revisions.
Update 18.3.0 -> Revisions 18.2.1 or 18.2.2 OR to Update 18.2.0
If database is at Revision 18.2.2 at the moment, the possible patching path could be :
Revision 18.2.2 -> Revisions 18.3.1 , 18.3.2, 18.4.1 and so on or Revision 18.2.2 -> Updates 18.4.0 , 18.5.0 and so on.
Below patching path is NOT supported, Because Update 18.3.0 is non-cumulative to 18.2.2.
Revision 18.2.2 -> Revision 18.2.1 or to Update 18.3.0