Thanks for saying this. The birthday paradox calculation is far more relevant to determining collision risks. Rule of thumb: if you have N random IDs, then afte

Thanks for saying this. The birthday paradox calculation is far more relevant to determining collision risks. Rule of thumb: if you have N random IDs, then after sqrt(N) IDs are generated there's a 50% probability of a single collision. Fortunately the sqrt(2^122) is still 2^62, or a very large number of IDs. But 64 bit random IDs have a collision after only 2^32, or 4 billion, and that has happened in practice in several systems.