UUID VS nanoid

I'd recommend using either Ramsey/uuid or generating a random number using random_bytes(32) then compressing it. 32 bits of randomness should be sufficient for most programs.

Of course, theoretical math and applied math often work out differently. Here's a thread with a guy claiming his team's software is running into "Several hundred [UUID] collisions per day"

Or just use a library.

I'll leave this here https://github.com/ramsey/uuid/issues/80

Not really in the realm of “thousands” of runs, but UUID collisions are possible and have been observed multiple times after only 1 million generations due to unknown reasons.

There's also the risk of bad randomness sources and/or bugs.

One popular UUID library got a bug report stating: "We are generating about 1M UUID4 a day, and we are getting several hundred collisions a day". And so they were; turned out to be a bug/weird interaction between the OpenSSL library they were using for randomness and forking. (Details here, although it was all fixed years ago of course: https://github.com/ramsey/uuid/issues/80)

On paper, you should never, ever, ever see a collision when generating a mere million v4 UUIDs a day, much less hundreds of collisions. But that doesn't mean it can't happen!

This is also an interesting bit of analysis; comes from a company that processed a lot of UUIDs generated in browsers, checked, and discovered about 5 collisions per million UUIDs. Again, not what you'd naively expect! (Turned out to be mostly driven by misbehaving crawlers.) https://medium.com/teads-engineering/generating-uuids-at-sca...

just make sure you have everything configured correctly on your system if using UUIDs:

https://github.com/ramsey/uuid/issues/80

In the types of systems that need UUIDs there is probably no easy way to check for collisions. The prospect of mystery data corruption with no ability to trace it down frightens the hell out of me.

The only reason that issue was reported is because someone was actually doing the collision checking. That's not going to be the norm in UUID systems. Think about it.

In theory the risk of collision is so small it can be written off, but implementations can have bugs.

Last thing left is to use our new upload function in our server action. Since I like to upload images in single format and have some more control over them, I will additionally use sharp library. For file name, I'll generate some random string using nanoid:

Our API is in node. And God, how I suffered to import nanoid in an esmodule project. I had to vendor it, since using a previous version was not ideal. With bun, we can no longer worry about that. Just import what you need and done.

No thread about UUID is complete without a plug for NanoID! https://github.com/ai/nanoid/blob/main/README.md

Generate a unique file name using the nanoid library.

The syntax should read similar to SQL itself. We’re using a Python port of nanoid to generate our IDs. There’s only one thing missing… how do we actually create the table?

I usually go for Nano Id for new projects https://github.com/ai/nanoid

Nano ID

In another comment I mentioned I use nanoid in my projects now. It has a default space of 64^21 and has an a page where you can play with key lengths and alphabet sizes and see the probability of collisions :

https://zelark.github.io/nano-id-cc/

At the default 64 character alphabet with a 21 character key length it would take ~41 million years in order to have a 1% probability of at least one collision if you generated 1000 ids per second.

Using randomly generated IDs like Nano ID could be a good alternative, however, as a developer, we must understand what Nano ID really does in our application. Defining the number of characters in the generated IDs is also important, to help with that Nano ID has a Collision Calculator to give us how many years in order to have a 1% probability of collision.