Re: Is there a way (except from server logs) to know the kind of on-going/last checkpoint?

On Wed, Dec 8, 2021 at 4:07 AM Justin Pryzby <pryzby@telsasoft.com> wrote:
> > I'd bet squashing all of this into a single string (not really a flag)
> > will just mean people will have to parse it, etc. Keeping individual
> > boolean flags (or even separate string fields) would be better, I guess.
>
> Since the size of controldata is a concern, I suggest to add an int16 to
> populate with flags, which pg_controldata can parse for display.

+1. I will come up with a patch soon.

> Note that this other patch intends to add the timestamp and LSN of most recent
> recovery to controldata.
> https://commitfest.postgresql.org/36/3183/

Thanks. I will go through it separately.

> > We already have some checkpoint info in pg_stat_bgwriter, but that's
> > just aggregated data, not very convenient for info about the current
> > checkpoint. So maybe we should add pg_stat_progress_checkpoint, showing
> > various info about the current checkpoint?
>
> It could go into the pg_stat_checkpointer view, which would be the culmination
> of another patch (cc Melanie).
> https://commitfest.postgresql.org/36/3272/

+1 to have pg_stat_progress_checkpoint view. We have
CheckpointStatsData already. What we need is to make this structure
shared and add a little more info to represent the progress, so that
the other backends can access it. I think we can discuss this in a
separate thread to give it a fresh try rather than proposing this as a
part of another thread. I will spend some time on
pg_stat_progress_checkpoint proposal and try to come up with a
separate thread to discuss.

Regards,
Bharath Rupireddy.