Re: Report checkpoint progress with pg_stat_progress_checkpoint (was: Report checkpoint progress in server logs)

> > Thank you for sharing the information. 'triggering backend PID' (int)
> > - can be stored without any problem.
>
> There can be multiple processes triggering a checkpoint, or at least wanting it
> to happen or happen faster.

Yes. There can be multiple processes but there will be one checkpoint
operation at a time. So the backend PID corresponds to the current
checkpoint operation. Let me know if I am missing something.

> > 'checkpoint or restartpoint?'
>
> Do you actually need to store that? Can't it be inferred from
> pg_is_in_recovery()?

AFAIK we cannot use pg_is_in_recovery() to predict whether it is a
checkpoint or restartpoint because if the system exits from recovery
mode during restartpoint then any query to pg_stat_progress_checkpoint
view will return it as a checkpoint which is ideally not correct. Please
correct me if I am wrong.

Thanks & Regards,
Nitin Jadhav

On Thu, Feb 17, 2022 at 4:35 PM Julien Rouhaud <rjuju123(at)gmail(dot)com> wrote:
>
> Hi,
>
> On Thu, Feb 17, 2022 at 12:26:07PM +0530, Nitin Jadhav wrote:
> >
> > Thank you for sharing the information. 'triggering backend PID' (int)
> > - can be stored without any problem.
>
> There can be multiple processes triggering a checkpoint, or at least wanting it
> to happen or happen faster.
>
> > 'checkpoint or restartpoint?'
>
> Do you actually need to store that? Can't it be inferred from
> pg_is_in_recovery()?