Horton

Re: UUID v7

x4mmm@yandex-team.ru

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From: "Andrey M. Borodin" <x4mmm@yandex-team.ru>
To: Michael Paquier <michael@paquier.xyz>
Cc: Sergey Prokhorenko <sergeyprokhorenko@yahoo.com.au>, Jelte Fennema-Nio <postgres@jeltef.nl>, Aleksander Alekseev <aleksander@timescale.com>, pgsql-hackers mailing list <pgsql-hackers@postgresql.org>, Peter Eisentraut <peter@eisentraut.org>, Przemysław Sztoch <przemyslaw@sztoch.pl>, "David G. Johnston" <david.g.johnston@gmail.com>, Mat Arye <mat@timescaledb.com>, Matthias van de Meent <boekewurm+postgres@gmail.com>, Nikolay Samokhvalov <samokhvalov@gmail.com>, Junwang Zhao <zhjwpku@gmail.com>
Date: 2024-10-18T05:35:16Z
Lists: pgsql-hackers 

> On 16 Oct 2024, at 11:05, Michael Paquier <michael@paquier.xyz> wrote:
> 
> This part of the patch looks structurally wrong to me because we've
> already spent some time refactoring the clock APIs into instr_time.h
> that deals about cross-platform requirements for monotonic times.
> Particularly, on MacOS, we have CLOCK_MONOTONIC_RAW, and your patch
> does not use it.  So you should avoid calling these routines, and
> build something using the interface unified across the board, like
> anywhere else.  And you know, duplication.

Thanks for looking!
Actually, CLOCK_MONOTONIC_RAW on MacOS was exactly a problem: this clocks have nothing to do with astronomic clock. And we must put real UTC time into UUID.
I’d be happy to reuse instr_time.h infrastructure, but it just does not fit for the purpose. It’s optimized to measure time spans.


Best regards, Andrey Borodin.

Commits

  1. Fix timestamp overflow in UUIDv7 implementation.

  2. Add UUID version 7 generation function.

  3. Add some UUID support functions