Set as a whole or not at all, mirroring the table's CHECK: an active key is null, a superseded one names its replacement and the date it should stop being used. There is no third state and no half-set pair.
null
Set as a whole or not at all, mirroring the table's CHECK: an active key is
null, a superseded one names its replacement and the date it should stop being used. There is no third state and no half-set pair.