Re: What is a typical precision of gettimeofday()?

Aleksander Alekseev <aleksander@timescale.com>

From: Aleksander Alekseev <aleksander@timescale.com>

To: pgsql-hackers <pgsql-hackers@postgresql.org>

Cc: "Andrey M. Borodin" <x4mmm@yandex-team.ru>, Tom Lane <tgl@sss.pgh.pa.us>, Hannu Krosing <hannuk@google.com>, Peter Eisentraut <peter@eisentraut.org>

Date: 2024-07-03T08:48:44Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Force LC_NUMERIC to C while running TAP tests.
- f25792c541e5 19 (unreleased) landed
Minor tweaks for pg_test_timing.
- 9dcc7641444f 19 (unreleased) landed
Change pg_test_timing to measure in nanoseconds not microseconds.
- 0b096e379e6f 19 (unreleased) landed

Hi,

> That’s a very interesting result, from the UUID POV!
> If time is almost always advancing, using time readings instead of a counter is very reasonable: we have interprocess monotonicity almost for free.
> Though time is advancing in a very small steps… RFC assumes that we use microseconds, I’m not sure it’s ok to use 10 more bits for nanoseconds…

A counter is mandatory since someone can for instance change the
system's time while the process is generating UUIDs. You can't
generally assume that local time of the system is monotonic.

-- 
Best regards,
Aleksander Alekseev