Re: Repeating autovacuum

On Fri, Apr 7, 2017 at 7:33 PM, Ertan Küçükoğlu <ertan(dot)kucukoglu(at)1nar(dot)com(dot)tr
> wrote:

>
>
> On 8 Apr 2017, at 01:53, David G. Johnston <david(dot)g(dot)johnston(at)gmail(dot)com>
> wrote:
>
> On Fri, Apr 7, 2017 at 3:35 PM, Ertan Küçükoğlu <
> ertan(dot)kucukoglu(at)1nar(dot)com(dot)tr> wrote:
>
>> No autovacuum parameters are changed or used. They are all remarked as in
>> default config file.
>>
>> I wonder if that is a normal behavior as system is idle.
>>
>
> ​See "autovacuum_naptime (integer)"
>
> https://www.postgresql.org/docs/current/static/runtime-
> config-autovacuum.html
>
> Its "auto" vacuum which means it runs (nearly) continuously looking for
> things to do.
>
> I suppose that in theory it could operate in a kind of "wait/notify" mode
> where every DDL against the database wakes the daemon otherwise it stays
> asleep. I recall some work being done a number of years back on making the
> system more energy efficient during no-activity periods - but there are
> trade-offs to consider here for which I am not up-to-speed on the specifics.
>
> It would be interesting to see the timestamps on those log entries...
>
> David J.
>
> I don't see any timestamp in the log. I myself wanted that, too. Do I need
> to turn some switch on?
>
> Ertan Küçükoğlu
>

Look at log_line_prefix for postgresql.conf. There's a whole set of macros
you can use to add logging information, including timestamps.

https://www.postgresql.org/docs/9.6/static/runtime-config-logging.html#GUC-LOG-LINE-PREFIX

Keith