如果你所说的“有足够的时间”是指100年，你以每秒10亿的速度创造它们，那么是的，100年后你有50%的几率发生碰撞。

如果你所说的“有足够的时间”是指100年，你以每秒10亿的速度创造它们，那么是的，100年后你有50%的几率发生碰撞。

我同意其他的答案。uuid对于几乎所有的实际用途都是足够安全的，当然对你来说也是如此。

但假设(假设)它们不是。

是否有更好的系统或某种类型的模式来缓解这个问题?

这里有一些方法:

Use a bigger UUID. For instance, instead of a 128 random bits, use 256 or 512 or ... Each bit you add to a type-4 style UUID will reduce the probability of a collision by a half, assuming that you have a reliable source of entropy2. Build a centralized or distributed service that generates UUIDs and records each and every one it has ever issued. Each time it generates a new one, it checks that the UUID has never been issued before. Such a service would be technically straight-forward to implement (I think) if we assumed that the people running the service were absolutely trustworthy, incorruptible, etcetera. Unfortunately, they aren't ... especially when there is the possibility of governments' security organizations interfering. So, this approach is probably impractical, and may be3 impossible in the real world.

1 - If uniqueness of UUIDs determined whether nuclear missiles got launched at your country's capital city, a lot of your fellow citizens would not be convinced by "the probability is extremely low". Hence my "nearly all" qualification. 2 - And here's a philosophical question for you. Is anything ever truly random? How would we know if it wasn't? Is the universe as we know it a simulation? Is there a God who might conceivably "tweak" the laws of physics to alter an outcome? 3 - If anyone knows of any research papers on this problem, please comment.

摘自维基百科:

因此，任何人都可以创建UUID并使用 用它来表示某物 合理相信 标识符永远不会是 无意中被某人用于 其他东西

它还非常详细地解释了它的安全性。所以回答你的问题:是的，它足够安全。

UUID方案通常不仅使用伪随机元素，还使用当前系统时间和某种通常唯一的硬件ID(如果可用的话)，比如网络MAC地址。

使用UUID的关键在于，您相信它能够比您自己更好地提供唯一的ID。这与使用第三方加密库而不是自己开发加密库的原理相同。自己做可能更有趣，但这样做通常不那么负责任。

我已经做了很多年了。永远不要遇到问题。

我通常设置我的数据库有一个表，其中包含所有的键和修改的日期等。我从没遇到过钥匙重复的问题。

它的唯一缺点是，当您编写一些查询来快速查找一些信息时，您需要进行大量的复制和粘贴键。你不再有简单易记的id了。