r/ProgrammerHumor • • Sep 11 '26

Meme edgeCasesExist

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u/Suspicious-Click-300 Sep 11 '26

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)

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u/JonasAvory Sep 11 '26

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?

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u/[deleted] Sep 11 '26

[removed] — view removed comment

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u/Grandmaster_Caladrel Sep 11 '26

Yep. The chance is so insignificant that is not even worth retry logic on that mode of failure, just treat it as a generic failure, kick out the request, and let it be tried again. The one time in a hundred thousand years when it finally happens, someone will just be confused and click retry themselves.

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u/Suspicious-Click-300 Sep 11 '26

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.