Re: Inconsistency in reporting checkpointer stats

On Fri, Dec 16, 2022 at 2:14 PM Kyotaro Horiguchi
<horikyota(dot)ntt(at)gmail(dot)com> wrote:
>
> In the first place I don't like that we count the same things twice.
> Couldn't we count the number only by any one of them?
>
> If we remove CheckPointerStats.ckpt_bufs_written, CreateCheckPoint can
> get the final number as the difference between the start-end values of
> *the shared stats*. As long as a checkpoint runs on a single process,
> trace info in BufferSync will work fine. Assuming single process
> checkpointing there must be no problem to do that. (Anyway the current
> shared stats update for checkpointer is assuming single-process).

What if someone resets checkpointer shared stats with
pg_stat_reset_shared()? In such a case, the checkpoint complete
message will not have the stats, no?

--
Bharath Rupireddy
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com