Re: O(n) tasks cause lengthy startups and checkpoints

On Mon, Nov 28, 2022 at 1:31 PM Andres Freund <andres(at)anarazel(dot)de> wrote:
> On 2022-11-28 13:08:57 +0000, Simon Riggs wrote:
> > On Sun, 27 Nov 2022 at 23:34, Nathan Bossart <nathandbossart(at)gmail(dot)com> wrote:
> > > > Rather than explicitly use DEBUG1 everywhere I would have an
> > > > #define CUSTODIAN_LOG_LEVEL LOG
> > > > so we can run with it in LOG mode and then set it to DEBUG1 with a one
> > > > line change in a later phase of Beta
> > >
> > > I can create a separate patch for this, but I don't think I've ever seen
> > > this sort of thing before.
> >
> > Much of recovery is coded that way, for the same reason.
>
> I think that's not a good thing to copy without a lot more justification than
> "some old code also does it that way". It's sometimes justified, but also
> makes code harder to read (one doesn't know what it does without looking up
> the #define, line length).

Yeah. If people need some of the log messages at a higher level during
development, they can patch their own copies.

I think there might be some argument for having a facility that lets
you pick subsystems or even individual messages that you want to trace
and pump up the log level for just those call sites. But I don't know
exactly what that would look like, and I don't think inventing one-off
mechanisms for particular cases is a good idea.

--
Robert Haas
EDB: http://www.enterprisedb.com