Softhouse/indiskt — comment on commit 4babb0711d40a431c26f7549bcc0c0ad96ca992e
File: indiskt.sql line 34
By Tobbe:

But why? You already have (day, person) as a key. Why not use it as the primary key? Adding another column just adds to the complexity of the design. Always use the natural key (aka domain key) if there is one!