Horton

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

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: "Andrey M. Borodin" <x4mmm@yandex-team.ru>
Cc: Hannu Krosing <hannuk@google.com>, Peter Eisentraut <peter@eisentraut.org>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2024-07-03T08:03:16Z
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 →

  1. Force LC_NUMERIC to C while running TAP tests.

  2. Minor tweaks for pg_test_timing.

  3. Change pg_test_timing to measure in nanoseconds not microseconds.

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

Keep in mind also that instr_time.h does not pretend to provide
real time --- the clock origin is arbitrary.  But these results
do give me additional confidence that gettimeofday() should be
good to the microsecond on any remotely-modern platform.

			regards, tom lane