Properly handle multiple tiers backed by the same datasource when removing tiers
Properly handle multiple tiers backed by the same datasource when removing tiers

jeffhsu3/dalliance,jeffhsu3/dalliance,limeng12/dalliance,bartcharbon/dalliance,warelab/dalliance,dasmoth/dalliance,warelab/dalliance,limeng12/dalliance,Traksewt/dalliance,bartcharbon/dalliance,ENCODE-DCC/dalliance,ENCODE-DCC/dalliance,dasmoth/dalliance,Traksewt/dalliance