Re: UUID v7

x4mmm@yandex-team.ru

From: "Andrey M. Borodin" <x4mmm@yandex-team.ru>

To: Peter Eisentraut <peter.eisentraut@enterprisedb.com>

Cc: Tom Lane <tgl@sss.pgh.pa.us>, Daniel Gustafsson <daniel@yesql.se>, Matthias van de Meent <boekewurm+postgres@gmail.com>, Nikolay Samokhvalov <samokhvalov@gmail.com>, "Kyzer Davis (kydavis)" <kydavis@cisco.com>, Andres Freund <andres@anarazel.de>, Andrey Borodin <amborodin86@gmail.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, "brad@peabody.io" <brad@peabody.io>, "wolakk@gmail.com" <wolakk@gmail.com>, sergeyprokhorenko@yahoo.com.au

Date: 2023-08-21T08:42:20Z

Lists: pgsql-hackers

Attachments

v5-0001-Implement-UUID-v7-as-per-IETF-draft.patch (application/octet-stream) patch v5-0001
v5-0002-Buffer-random-numbers.patch (application/octet-stream) patch v5-0002
v5-0003-Use-cached-random-numbers-in-gen_random_uuid-too.patch (application/octet-stream) patch v5-0003

> On 20 Aug 2023, at 23:56, Andrey M. Borodin <x4mmm@yandex-team.ru> wrote:
> 
> <v4-0001-Implement-UUID-v7-as-per-IETF-draft.patch>

I've observed, that pre-generating and buffering random numbers makes UUID generation 10 times faster.

Without buffering
postgres=# with x as (select gen_uuid_v7() from generate_series(1,1e6)) select count(*) from x;
Time: 5286.572 ms (00:05.287)

With buffering
postgres=# with x as (select gen_uuid_v7() from generate_series(1,1e6)) select count(*) from x;
Time: 390.091 ms

This can speed up gen_random_uuid() on the same scale too. PFA implementation of this technique.

Best regards, Andrey Borodin.

Commits

Fix timestamp overflow in UUIDv7 implementation.
- a5419bc72e22 18.0 landed
Add UUID version 7 generation function.
- 78c5e141e9c1 18.0 landed
Add some UUID support functions
- 794f10f6b920 17.0 landed