在 10 亿次迭代中获得相同 GUID 的机会有多大？
我正在开展一个项目，需要生成大约 10 亿个 GUID。
我知道 GUID 不能保证是唯一的，但几乎始终是唯一的。
如果我生成了十亿个 GUID，那么匹配的概率是多少？
I am working on a project where I need to generate approximately 1 billion GUIDs.
I know GUIDs are not guaranteed to be unique but are unique almost all of the time.
If I generated a billion GUIDs, what is the probability that there will be a match?
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博文：GUID 是全局唯一的，但 GUID 的子字符串不是
.NET GUID 由
，所以 Oscar 引用的 UUID 概率在这里不起作用。但是，如果您从一台计算机创建所有 10 亿个 GUID，则没有机会获得重复项（除非您正在玩时钟；-）
Blogpost: GUIDs are globally unique, but substrings of GUIDs aren’t
The .NET GUID consists of
So the UUID probability quoted by Oscar does not work here. But if you create all your 1 billion GUIDs from one computer, there is no chance to get a duplicate (except you are playing with the clock ;-)
如果您从同一台机器创建 GUId 并使用相同的算法，那么您将不会发生冲突。
If you are creating the GUIds from the same machine and using the same algorithm then you will not get a collision.
http://en.wikipedia.org/wiki/Uuid#Random_UUID_probability_of_duplicates
概率
68,719,476,736 = 2^36 = 0.0000000000000004 = 4 × 10^−16)
2,199,023,255,552 = 2^41 = 0.0000000000004 = (4 × 10^−13)
70,368,744,177,664 = 2^46 = 0.000 0000004 = (4 × 10^−10)
http://en.wikipedia.org/wiki/Uuid#Random_UUID_probability_of_duplicates
n probability
68,719,476,736 = 2^36 = 0.0000000000000004 = 4 × 10^−16)
2,199,023,255,552 = 2^41 = 0.0000000000004 = (4 × 10^−13)
70,368,744,177,664 = 2^46 = 0.0000000004 = (4 × 10^−10)