If the database is not up to date, the log files are replayed from the point that the checkpoint file indicates. Jet logging and recovery can still recover a database without a checkpoint, but the checkpoint allows faster recovery by directing recovery to begin closer to logged operations that must be redone.
This article is 6 years old. Egypt's most famous pharaoh, King Tutankhamun, was a frail boy who suffered from a cleft palate and club foot, according to a study published today that shows he died of complications from a broken leg exacerbated by malaria and his parents were most likely brother and sister.
So maybe it wasn't the king's madness that caused his most famous symptom. It could have simply been his medicine. I interviewed the researchers at St George's for a new documentary series, Fit To Rule: How Royal Illness Changed History.