From: | Hannu Krosing <hannuk(at)google(dot)com> |
---|---|
To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
Cc: | "Andrey M(dot) Borodin" <x4mmm(at)yandex-team(dot)ru>, Peter Eisentraut <peter(at)eisentraut(dot)org>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: What is a typical precision of gettimeofday()? |
Date: | 2025-07-07 23:39:59 |
Message-ID: | CAMT0RQT9tbJgQ8NKqNowBbd=RRcMjM50Q9wSb_eGiX6VibyG0w@mail.gmail.com |
Views: | Whole Thread | Raw Message | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
On Mon, Jul 7, 2025 at 11:38 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> > Also added a flag to select number of direct values to show
>
> Hmm ... I agree with having a way to control the length of that output,
> but I don't think that specifying a count is the most useful way to
> do it. Particularly with a default of only 10, it seems way too
> likely to cut off important information.
>
> What do you think of instead specifying the limit as the maximum
> running-percentage to print, with a default of say 99.99%? That
> gives me results like
I agree that percentage covered is a much better metric indeed.
And I am equally ok with a default of either 99.9% or 99.99%.
I briefly thought of it but decided a simple count is simpler to
explain, especially for some potential corner cases of % .
But as pg_test_timing is not part of the server we really do not need
to worry about rare edge cases.
> Observed timing durations up to 99.9900%:
> ns % of total running % count
> 15 4.5452 4.5452 8313178
> 16 58.3785 62.9237 106773354
> 17 33.6840 96.6078 61607584
> 18 3.1151 99.7229 5697480
> 19 0.2638 99.9867 482570
> 20 0.0093 99.9960 17054
>
> In the attached I also made it print the largest observed
> duration, which seems like it might be useful information.
Yes, a useful piece of information indeed.
> As previously threatened, I also added a test case to
> improve the code coverage.
Thanks!
From | Date | Subject | |
---|---|---|---|
Next Message | Michael Paquier | 2025-07-07 23:42:54 | Re: Can can I make an injection point wait occur no more than once? |
Previous Message | Michael Paquier | 2025-07-07 23:38:41 | Re: Support for 8-byte TOAST values (aka the TOAST infinite loop problem) |