Comment 5 for bug 1569884

Based on Mike and Dans suggestion, here's the new patch,

http://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/collab/Callender/monograph_parts_new_constraints_index

I've tested it by repeatedly adding and deleting an identical monograph part in the biblio.monograph_part table and it will only allow one at a time per label, but there can be an unlimited amount of deleted ones using the same label.

Steve