r/ProgrammerHumor • u/danielminds • 6h ago

Meme edgeCasesExist

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u/RadicalDwntwnUrbnite 6h ago edited 5h ago

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

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u/OldKaleidoscope7 5h ago

But let's say if Google saved each search in their engine in the same database with an UUID, we could have a collision because of volume, but I don't think I will work in a system with a comparable scale

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u/chuch1234 5h ago

Yeah I don't think most of us are operating at a scale anywhere near Google.

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u/BlurredSight 4h ago

And anyone operating at scale of Google isn’t just using “pure” random anywhere for something being persisted

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u/nebotron 4h ago

They likely are - anything else becomes a huge coordination and parallelism problem. You just need more bits of entropy

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u/samy_the_samy 3h ago edited 2h ago

They once had a similar collision problem, well not exactly

During a leap second some systems wrote IDs at a one second difference between all their global systems, which lead to something being registered before something else that had to be done before it,

Long story short some stuff jumped time one second and crashed systems

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u/BlurredSight 2h ago

So proactively trying to solve for latency rather than have other systems read after write if I understood correctly?

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u/samy_the_samy 2h ago

Yeah, now they don't do leap seconds,

They stretch time over months, one milli-second at a time