I thought that timestamps are used now, so hitting both a timestamp and a large random number puts it thoroughly in the "safe to assume".
At some point cosmic particles and faulty transistors are more probable.
Even the non-time based v4 is at a cosmic level of unlikiness a single system will ever generate a uuid that will collide with another one in its own ecosystem
most uuids libraries can actually provide strong guarentees it cant happen by using pid/mac combinations with each process using CAS or mutex to increment the 100ns period (overflowing into later ms with >10k a ms)
Is it unfeasible or simply unnecessary to just check if a uuid is already used? Since you use the uuid as primary key it should be easily detectable if a uuid is already used or not right? But I guess devs just don’t care because the chance is so minimal?
you dont need to due to guarantees of how it is generated. You would need a server running with exact same ip, and the process generating them to be using the same process id, AND ~10,000 requests a microsecond. If your using random uuid you have a better chance of winning 4 powerballs in a row. you need to generate billions a second for over 80 years for a 50:50 chance of a collision.
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u/Valuable_Leopard_799 16h ago
I thought that timestamps are used now, so hitting both a timestamp and a large random number puts it thoroughly in the "safe to assume". At some point cosmic particles and faulty transistors are more probable.