Business View Rules
Do not remove columns from existing business views. Changing business views that applications use can cause unpredictable results when running the application. Hide columns at the application design level using either Form Design Aid or Report Design. Performance is not gained by deleting a few columns from a business view.
An upgrade preserves these changes:
New custom business views.
New columns or joins to the existing business views.
An upgrade replaces columns removed from business views.