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ULID: Universally Unique Lexicographically Sortable Identifier

61 points by der_gopher

by rdtsc

1 subcomments

> It is worth noting that the newest proposed standard for unique identifiers, UUID v7, aims to address the sortability and database performance issues of older UUID versions by adopting a similar time-ordered structure to ULID.
Yeah, I would go with UUID v7 at this point given that it's part of the UUID RFC https://datatracker.ietf.org/doc/html/rfc9562#name-uuid-vers...

by sedatk

6 subcomments

Whenever ULID comes up, I need to remind that it has a sequential ID generation mode in its spec which is prone to conflicts on multi-threads, processes or hosts which kills the purpose of a "universal" identifier. If you need a sequential ID, just use an integer, preferably one that's autoincremented by the database.
It's best to stick to UUIDv7 because of such quirks of ULID.

by nighthawk454

3 subcomments

by wafflestomp

0 subcomment

BTW, this doesn’t work well in S3 due to the timestamp being to the left of the randomness.

by elias1233

1 subcomments

I have always been a bit hesitant to use UUIDs with timestamps as it can be a security issue if the IDs are public. For example getting the age of a user account just from the id. I will say, however, that I have not heard of any major incidents stemming from this.

by swyx

0 subcomment

i keep a list of UUID info: https://github.com/swyxio/brain/blob/master/R%20-%20Dev%20No...
for those also learning

by sblom

1 subcomments

I love the aesthetics. The cryptographic strength tradeoffs (against UUIDv7) seem rough for a lot of applications, though.

0 subcomment

by catlover76

0 subcomment

by pklausler

0 subcomment

Universally distinct would seem more correct than unique, at least mathematically speaking, unless there's only ever going to be just one of them.

by N_Lens

0 subcomment

Interesting article noting how ULIDs solve database index fragmentation caused when using UUIDv4. However, for extremely high-volume writes, ULIDs create "hot spots" at the current timestamp index location, potentially causing contention. The article notes that UUID v7 (newly standardized) adopts the same time-ordered approach, validating ULID's design.