ksuid VS nanoid

OP here - we avoid sequences in all but one part of our application due to a dependency. We use [KSUIDs][1] and UUID v4 in various places. This one "gotcha" applies to any sequence, so it's worth calling out as general advice when running a migration like this.

[1]: https://segment.com/blog/a-brief-history-of-the-uuid/

UUID v4 isn't large enough to prevent collisions, that is why segment.io created https://github.com/segmentio/ksuid which is 160bit vs the 128bit of a UUIDv4.

Assuming you don't need to use UUIDv7 (or any UUID's) then https://github.com/segmentio/ksuid provides a much bigger keyspace. You could just append a string prefix if you wanted to namespace, but the chance of collisions of a KSUID is many times smaller than a UUID of any version.

KSUID's are have temporal-lexicographical order plus 128 bits of entropy, which is more than UUIDv4.

https://github.com/segmentio/ksuid

That's why you use ksuid (https://segment.com/blog/a-brief-history-of-the-uuid/) or, if you're willing to go with a draft spec you could go with the new UUID formats https://www.ietf.org/archive/id/draft-ietf-uuidrev-rfc4122bi...

Interesting in more history of UUIDs? Twilio Segment's blog has an amazing history lesson about how they came to be.

I use the ksuid from segment. https://github.com/segmentio/ksuid

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.