All major mainstream databases are update in-place and have a notion of NOW rather than a progression of time. They are supposed to be a reflection of real life, but are they really? When you save a Customer and their address changes, does that mean they never used to live at the old place? What if your DB started behaving like a git repo instead and recorded each change as a series of changes or facts? What if you could time travel in the DB and look back at any point of time? And do it with the similar performance as any of the usual DBs? What if CRUD isn't the right way of thinking of DBs? Let's discuss about DBs which make this possible and not only radically change your thought process about data and facts but also simplify everything around the DB: the app, the infra and the monitoring tooling! Let's be functional at the disk too and not just the app.