It’s true, if the only goal of a UUID was minimizing collisions with a given number of bits, storing the timestamp would be a waste of entropy (assuming that ge

It’s true, if the only goal of a UUID was minimizing collisions with a given number of bits, storing the timestamp would be a waste of entropy (assuming that generation rate is non-uniform over time.) The reason they encode a timestamp (which I learned from the link upthread) is interesting, though. They knew that people use UUIDs as keys in data structures like BTrees, and using a timestamp improves memory/disk locality. > Non-time-ordered UUID versions such as UUIDv4 have poor database index locality. Meaning new values created in succession are not close to each other in the index and thus require inserts to be performed at random locations. The negative performance effects of which on common structures used for this (B-tree and its variants) can be dramatic.