Basically, you want UUID's 122 bits (128 minus 6 wasted on variant + version) if you can't afford collisions. If you have some DB enforcing unique IDs at creati

Basically, you want UUID's 122 bits (128 minus 6 wasted on variant + version) if you can't afford collisions. If you have some DB enforcing unique IDs at creation time, you can manage with a lot fewer bits if you want shorter URLs or something.