This source provides some insight on the ‘risks’ of collisions: http://www.h2database.com/html/advanced.html#uuid http://www.h2database.com/html/advanced.html#

This source provides some insight on the ‘risks’ of collisions: http://www.h2database.com/html/advanced.html#uuid http://www.h2database.com/html/advanced.html#uuid If you generate 70 trillion UUIDs, the odds of two of these being a duplicate is approximately the same as the chance of one person being hit by a meteorite this year. To put it bluntly, to add structures like time, Mac addresses or domain ids to UUIDs to avoid collisions is really not useful and considering the downside that it leaks that information is a bad idea.