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💤🌵🤖@cactus2/12/2023, 9:25 PM

iliana @iliana

💤🌵🤖@cactus2/12/2023, 6:41 AM

UUID versions through the ages

UUIDs are neat. y'know, cfbff0d1-9375-5685-968c-48ce8b15ae17 type of shit. if you're like me until a few days ago, all you know about the types of UUID is that v4 is the good one. but why are there other ones? is there a secret better one? why are the dashes asymmetrical? let's take a (roughly paraphrased from wikipedia and probably not quite accurate) look.

#effortposting #UUIDs

iliana @iliana2/12/2023, 8:10 PM

some notes on further research i did that's relevant to me and maybe you, the reader of this share?

the Internet-Draft linked above has now been moved into the IETF "UUIDREV Working Group", if you want to read the latest draft and have opinions: https://datatracker.ietf.org/doc/draft-ietf-uuidrev-rfc4122bis/ https://github.com/ietf-wg-uuidrev/rfc4122bis — looks like it is still actively being worked on which is great.
UUIDv7 looks a lot like ULID! but also the ULID spec looks like it has languished a bit, despite a number of requests for clarification etc.
the uuid Rust crate starting in 1.2.0 has support for generating UUIDv7. yay! i'm going to go use that now. [edit: ugh they're being responsible and making you pass RUSTFLAGS="--cfg uuid_unstable" until the spec passes i guess. ugh]

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in reply to @cactus's post:

Kara @kaara2/12/2023, 6:56 AM

Wikipedia link is broken :(

Thanks for the write up !

💤🌵🤖@cactus2/12/2023, 7:04 AM

wikipedia link is debroken, idk how that happened

Calyo Delphi @dragon-architect2/12/2023, 2:00 PM

YOU WROTE THIS ENTIRE POST JUST SO YOU COULD MAKE THAT JOKE AT THE END 🤣

But also, this is extremely informative! I was considering using UUID to uniquely identify all database content in a CMS engine I'm writing from (almost) scratch for my own website, and this gives me a lot more information, concisely summarized, to digest about them! Thank you!

Maynard @Quelklef2/12/2023, 6:36 PM

this was a fun read!

you know, ive always rolled my own identifier format (mostly for shits and giggles), and usually when i do so i get a little voice in my head worried that rolling our own is Bad because UUID is The Standard and probably Knows Better. but now i see that the UUID folk are also just having shits and giggles and all of their formats are fucked up too 😌

walking mirage @atomicthumbs2/12/2023, 7:37 PM

i love an extensive deep dive and horrible pun thank you

Debabrata Bhattacharya @D-Bhatta2/12/2023, 7:37 PM

Nice post. Gonna read it slowly this week. Bookmarked.

John Colagioia @jcolag2/12/2023, 8:42 PM

I had to dig through a lot of that information for a previous job (a predecessor decided that he could design a better scheme, and somehow, nobody kicked him in the shins to stop him, and I needed to kinda-sorta undo that history and replace his "Peculiar-IDs"), so I can confidently say that this is extremely well done.

cthuflu @cthuflu2/12/2023, 8:51 PM

This post made me realize I screwed up a migration from numerical to UUID format by generating purely based on numerical ID with the rest as 0s.

Well, that's in production forever.

💤🌵🤖@cactus2/12/2023, 9:18 PM

well, if the variant field winds up as 0, none of the rest of the spec applies, so you're probably fine

Kauko @kauko2/12/2023, 9:28 PM

I knew v4 was what you use to not let the MAC address be involved anymore but gdang there's a lot going on in uuid-land!

Chubby cuddlebot Lemma!@LemmaEOF2/12/2023, 11:19 PM

man UUIDs are a bit of a mess huh, I guess there's not really any other way a standard could turn out though

@darryl @darryl2/13/2023, 1:00 AM

I’m still reading but

this is some 5 Minute Crafts tier lifehackery. please refrain.

was gold and I’m following you now.

@darryl @darryl2/13/2023, 1:10 AM

Ok yeah the whole thing was really great, A++, would read again

Bryan H.@MegaMasterX2/13/2023, 1:01 AM

I was going to comment on how fantastically written this is until I landed at the very end and it hit me like someone kicking the back of my knee

Fluffies🐾 & ☉∇ ΘΔ Ⓥ @Fluffies2/13/2023, 2:10 PM

Mmmm. So if you want to do UUIDs with different hash functions, then teeeechnically you can throw that into v8 and still be in spec!

💤🌵🤖@cactus2/13/2023, 4:08 PM

and that might actually be the canonical solution

in reply to @iliana's post:

purely dysfunctional catgirl @leftpaddotpy2/13/2023, 6:07 AM

another fun fact: uuid_generate_v1mc in postgres will generate a uuid v1 with a random mac address (minus one bit), so it is not just a timestamp and predictable shit

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