Re: [HACKERS] log_destination=file - Mailing list pgsql-hackers

From Dmitry Dolgov
Subject Re: [HACKERS] log_destination=file
Date
Msg-id CA+q6zcWrX7Yo6FsdGHv6FR0EYjK8_vx=EQKUGJ8_DfjynmHRDg@mail.gmail.com
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In response to Re: [HACKERS] log_destination=file  (Dmitry Dolgov <9erthalion6@gmail.com>)
Responses Re: [HACKERS] log_destination=file
List pgsql-hackers
> On 7 September 2017 at 15:46, Dmitry Dolgov <9erthalion6@gmail.com> wrote:
>
> It seems that for this particular workload it was about 20-25% slower.​

Hmm...looks like I provided misleading data, sorry. The numbers from previous
email are correct and I'm able to reproduce them, but surprisingly for me only
for one particular situation when `log_statement=all; log_destination=stderr`
and stderr is sent to a console with a tmux session running in it (and apparently
it has some impact on the performance, but I'm not sure how exactly). In all
other cases (when stderr is sent to a plain console, /dev/null, or we send logs
to a file) numbers are different, and the difference between patch and master
is quite less significant.

average latency:

clients     patch       master

10          0.321       0.286

20          0.669       0.602

30          1.016       0.942

40          1.358       1.280

50          1.727       1.637

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