This is one of those cases where examples of natural keys failing are so ubiquitous that they are almost redundant. For the group who have forged a career with

This is one of those cases where examples of natural keys failing are so ubiquitous that they are almost redundant. For the group who have forged a career with natural keys, and never regretted it, more power to you. Great. However to the rest of us, myself included, where ill-considered natural keys have caused endless opinions and suffering, my commiserations. If I could send back one piece of advice to junior-me it would be to avoid natural primary keys. (Ideally with the corollary to avoid sequences, but that's another thread for another day.)