The UUID time-swapping trick seems like a bad idea outside of special cases. Overloading the UUID in this way makes you dependent on generating UUIDs correctly

The UUID time-swapping trick seems like a bad idea outside of special cases. Overloading the UUID in this way makes you dependent on generating UUIDs correctly so that the ordering works. You can get insertion ordering by using an auto-increment integer primary key which also results in a relatively short key for secondary indexes. This is much easier to understand and cannot be messed up by application errors.