Remix.run Logo
▲ skrebbel 5 hours ago

I feel like this article way downplays the entire point of UUIDv7s, which is that it lets you sort (and store!) your data kinda sorta by creation time, no overlap ever. That's great for cursors, for streaming data, for twitter clones, for chat messages, for player moves, and so on and so forth. Nearly everything that's vaguely realtimey that you might like to both persist and broadcast live to other clients, and displayed in a stable & reasonable order, benefits from a property like this.

In fairness, he does mention this, but squeezes it into a single sentence near the end. But eg the fact that you can't reliably extract the precise timestamp from the UUIDv7 is a feature, not a bug. It's either that or collisions and you don't want the collisions.

▲vbezhenar 22 minutes ago | parent | next [-]

You probably can't use that for streaming. Moment of UUID generation and moment of transaction commit are different, so it's very possible that even if your code generates UUIDs strictly sequentially; the observable sequence from the database will not be always sequential. I've been bitten by this once when I've used serial IDs and I don't think that UUIDv7 is any different in that regard.

▲roughly 5 hours ago | parent | prev [-]

Yeah, I think the key here is that you have to know what the limitations are. UUIDv7 does _not_ provide you with sorted and ordered IDs by creation time, it provides you with _kinda sorta_ sorted and ordered IDs by creation time. That's probably fine for a lot of use cases, but if it's not OK for yours (forensic accounting, risk mitigation for banks, whatever), you can't use it for that. You're right it's not a technical problem necessarily, but when the marketing material describes something without an asterisk, people who are unaware that what's being described is impossible at the limits can make bad system design decisions based on that promise.