Randomizing Strings In A Microservices World

[Tim Daneliuk]

On 12/10/19 12:37 PM, Chris Angelico wrote:
> On Wed, Dec 11, 2019 at 5:01 AM Tim Daneliuk <info at 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
> 


Close enough for my purposes.  Thanks.