| From: | Andrey Borodin <x4mmm(at)yandex-team(dot)ru> |
|---|---|
| To: | Jelte Fennema-Nio <postgres(at)jeltef(dot)nl> |
| Cc: | Przemysław Sztoch <przemyslaw(at)sztoch(dot)pl>, Sergey Prokhorenko <sergeyprokhorenko(at)yahoo(dot)com(dot)au>, Aleksander Alekseev <aleksander(at)timescale(dot)com>, pgsql-hackers mailing list <pgsql-hackers(at)postgresql(dot)org>, Nick Babadzhanian <pgnickb(at)gmail(dot)com>, Mat Arye <mat(at)timescaledb(dot)com>, Peter Eisentraut <peter(dot)eisentraut(at)enterprisedb(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Daniel Gustafsson <daniel(at)yesql(dot)se>, Matthias van de Meent <boekewurm+postgres(at)gmail(dot)com>, Nikolay Samokhvalov <samokhvalov(at)gmail(dot)com>, "Kyzer Davis (kydavis)" <kydavis(at)cisco(dot)com>, Andres Freund <andres(at)anarazel(dot)de>, "brad(at)peabody(dot)io" <brad(at)peabody(dot)io>, Kirk Wolak <wolakk(at)gmail(dot)com> |
| Subject: | Re: UUID v7 |
| Date: | 2024-01-18 13:17:54 |
| Message-ID: | 1ED19D0E-BDA6-4B1B-9722-2322B69CE151@yandex-team.ru |
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| Lists: | pgsql-hackers |
> On 17 Jan 2024, at 02:19, Jelte Fennema-Nio <postgres(at)jeltef(dot)nl> wrote:
I want to ask Kyzer or Brad, I hope they will see this message. I'm working on the patch for time extraction for v1, v6 and v7.
Do I understand correctly, that UUIDs contain local time, not UTC time? For examples in [0] I see that "A.6. Example of a UUIDv7 Value" I see that February 22, 2022 2:22:22.00 PM GMT-05:00 results in unix_ts_ms = 0x017F22E279B0, which is not UTC, but local time.
Is it intentional? Section "5.1. UUID Version 1" states otherwise.
If so, I should swap signatures of functions from TimestampTz to Timestamp.
I'm hard-coding examples from this standard to tests, so I want to be precise...
If I follow the standard I see this in tests:
+-- extract UUID v1, v6 and v7 timestamp
+SELECT uuid_extract_time('C232AB00-9414-11EC-B3C8-9F6BDECED846') at time zone 'GMT-05';
+ timezone
+--------------------------
+ Wed Feb 23 00:22:22 2022
+(1 row)
Current patch version attached. I've addressed all other requests: function renames, aliases, multiple functions instead of optional params, cleaner catalog definitions, not throwing error when [var,ver,time] value is unknown.
What is left: deal with timezones, improve documentation.
Best regards, Andrey Borodin.
[0] https://datatracker.ietf.org/doc/html/draft-ietf-uuidrev-rfc4122bis#name-example-of-a-uuidv1-value
| Attachment | Content-Type | Size |
|---|---|---|
| v10-0001-Implement-UUID-v7-as-per-IETF-draft.patch | application/octet-stream | 15.1 KB |
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