@What version of PPM are you on?
14.4.0.234
@Can you also give more details about what you mean by it has been 'deleted', was this undertaken by the Object - Views, or the Object - Attributes, the first you can certainly remove it from the edit and list views. The second Object - Attributes you should not be able to.
I'm talking about the Object - Attributes, the "Overall Status" just vanished from there.
@Have you modified the calculation from the Object - Attributes area?
Nope, didn't touch the attribute, it just vanished by itself.
@Finally, the Status Report Listing Query is driven from a database view odf_cop_prj_statusrpt_v2. This view gets recreated every time the Status Report object is modified - yes it does include cop_overall_status, but it is a calculated value, not an actual database field. However, if you did manage to delete the attribute from Object - Attributes, then this view should have been re-created, minus cop_overall_status.
But how can I re-create it with the cop_overall_status, or just re-add it? The attribute itself still exists, because the system tells me the attribute name still exists in the database.