On Wed, Dec 11, 2019 at 5:01 AM Tim Daneliuk <i...@tundraware.com> wrote: > > On 12/10/19 10:36 AM, Peter Pearson wrote: > > Just to be sure: you *are* aware that the "Birthday Paradox" says > > that if you pick your 10-digit strings truly randomly, you'll probably > > get a collision by the time of your 10**5th string . . . right? > > I did not consider this, but the point is taken. > > Could you kindly point me to a source for calculating this given > n-digit numeric-only strings? >
The exact formula is pretty gnarly, but you can get remarkably close by assuming that you're likely to get a collision at the square root - which is half the exponent (so a 16-bit checksum will collide after about 2**8 examples, and a 128-bit UUID4 will collide after about 2**64 UUIDs are generated). https://en.wikipedia.org/wiki/Birthday_problem ChrisA -- https://mail.python.org/mailman/listinfo/python-list
