[Tostino]

Not OP, but UUID v7 is what you want for most database workloads (other than something like Spanner)

[tossandthrow]

I use the null uuid as primary key - never had any DB scaling issues.

[petalmind]

Yeah, no NULL is ever equal to any other NULL, so they are basically unique.

[Groxx]

You are also guaranteed to be able to retrieve your data, just query for '... is null'. No complicated logic needed!

[RedShift1]

Me still using bigints... Which haven't given me any problems. Wouldn't use it for client generated IDs but that is not what most applications require anyway.