Re: A few new options for CHECKPOINT

Greetings,

* Alvaro Herrera (alvherre@alvh.no-ip.org) wrote:
> On 2020-Dec-05, Stephen Frost wrote:
> > So- just to be clear, CHECKPOINTs are more-or-less always happening in
> > PG, and running this command might do something or might end up doing
> > nothing depending on if a checkpoint is already in progress and this
> > request just gets consolidated into an existing one, and it won't
> > actually reduce the amount of WAL replay except in the case where
> > checkpoint completion target is set to make a checkpoint happen in less
> > time than checkpoint timeout, which ultimately isn't a great way to run
> > the system anyway.
>
> You keep making this statement, and I don't necessarily disagree, but if
> that is the case, please explain why don't we have
> checkpoint_completion_target set to 0.9 by default?  Should we change
> that?

Yes, I do think we should change that..  In fact, I'd argue that we can
probably get rid of checkpoint_completion_target entirely as an option.
The main argument against that is that it could be annoying for people
upgrading, but changing the default to 0.9 would definitely be an
improvement.

Thanks,

Stephen