How Does PUM Distinguish Usage Monitor Data From Different Target Environments?

It seems that when you populate Usage Monitor Repository in PUM, it doesn’t distinguish which environment the data  comes from:  PS_PTIAUMPMTAGR.DBNAME is always set to ‘DBNAME’ (unless there is a different table that I don't know about). Should DBNAME be different so that the change package created for a specific environment shows usage data for that environment instead of all environments uploaded to the Usage Monitor Repository, or is the design meant to imply that there should only be one source of data for Usage Monitor? Thanks in advance!