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Thread: Is UUID in java absolutely unique?

  1. #1
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    Default Is UUID in java absolutely unique?

    Hello, everyone.

    I've got a need to generate a distributed unique id for every object that'll be transmitted in my distributed system. Can UUID be used under this circumstance?

  2. #2
    Member mjr's Avatar
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    Default Re: Is UUID in java absolutely unique?

    This should answer your question about UUID in your title.

    Universally unique identifier - Wikipedia, the free encyclopedia

    There are 340,282,366,920,938,463,463,374,607,431,768,211,45 6 possible UUIDs (16 to the 32nd power), or about 3 10^38. Or 340 undecillion.

    So the odds of you getting a duplicate copy, as you can see, are very infinitesimal.

    Another way of looking at it is this way:

    If you want to assign UUIDs to your objects, let's say you have seven billion objects. You would be able to assign over 48,611,766,702,991,100,000,000,000,000 UUIDs (That's 48 octillion) to each object. If my math is right.
    Last edited by mjr; June 29th, 2012 at 06:26 AM.

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