Also makes UNIQUE indices much harder to use. You can't just delete and later re-insert the same data, you need to "undelete" it instead, but that can actually

Also makes UNIQUE indices much harder to use. You can't just delete and later re-insert the same data, you need to "undelete" it instead, but that can actually mess up the chronology of the data, so then you need a separate table to track dates... and things just get over-engineered quickly...