Re: log_autovacuum_min_duration doesn't log VACUUMs

On Sun, Feb 12, 2017 at 9:20 PM, Jim Nasby <Jim(dot)Nasby(at)bluetreble(dot)com> wrote:
> On 2/10/17 2:33 PM, Robert Haas wrote:
>> That having been said, I think it could certainly be useful to have
>> more control over what DDL gets logged in foreground processes.
>
> FWIW, this is a significant problem outside of DDL. Once you're past 1-2
> levels of nesting SET client_min_messages = DEBUG becomes completely
> useless.
>
> I think the ability to filter logging based on context would be very
> valuable. AFAIK you could actually do that for manual logging with existing
> plpgsql support, but obviously that won't help for anything else.

Well, that's moving the goalposts a lot further and in an unrelated
direction. I don't think that it's a good idea to change the
semantics of log_autovacuum_min_duration in the way Simon is proposing
for the reasons I noted, but I think that an acceptable patch could be
100 lines of pretty straightforward code and documentation, like a new
GUC that controls this output for the vac-non-autovac case.
Fine-grained control over which commands get logged in general is
harder, but it's still only a moderately complex patch (I think).
Filtering based on the context in which the logging is happening
sounds extremely complicated; I'm not sure what sort of design for
that would even be reasonable and it seems like there might be
innumerable requests for additional frammishes culminating in some
sort of mini-language and getting committed right around the time
Zefram Cochrane makes his inaugural flight.

--
Robert Haas
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