Re: Disallow setting client_min_messages > ERROR?

On 2018-11-06 11:37:40 -0500, Tom Lane wrote:
> Andres Freund <andres(at)anarazel(dot)de> writes:
> > On 2018-11-06 11:19:40 -0500, Tom Lane wrote:
> >> Hence, I propose that we should disallow setting client_min_messages
> >> any higher than ERROR, and that this probably even amounts to a
> >> back-patchable bug fix.
> >>
> >> Thoughts?
>
> > Seems reasonable. I do think it's probably sensible to backpatch,
> > although I wonder if we shouldn't clamp the value to ERROR at log
> > emission error time, rather than via guc.c, so we don't prevent old code
> > / postgresql.conf that set client_min_messages to > ERROR.
>
> Hm, do you really think there is any?

I'm not sure. But it sounds like it'd possibly slow adoption of the
minor releases if we said "hey, make sure that you nowhere set
client_min_messages > ERROR", even if it's not particularly meaningful
thing to do, as it'd still imply a fair bit of work for bigger
applications with not great standards.

> And if there is, wouldn't we be breaking it anyway thanks to the
> behavioral change?

Yea, possibly. I'd assume that it'd mostly have been set out of a
mistake, and never really noticed, because it's hard to notice the
consequences when things are ok.

Greetings,

Andres Freund