Re: add checkpoint stats of snapshot and mapping files of pg_logical dir

On Mon, Mar 14, 2022 at 10:54:56AM +0530, Bharath Rupireddy wrote:
> Yes, this is a concern. Also, when there were no logical replication
> slots on a plain server or the server removed or cleaned up all the
> snapshot/mappings files, why would anyone want to have these messages
> with all 0s in the server log?

The default settings don't enable that, so making things conditional
roughly as you are suggesting with two different LOG messages sounds
rather fine.

> Here's what I'm thinking:
>
> Leave the existing "checkpoint/restartpoint complete" messages intact,
> add the following in LogCheckpointEnd:

FWIW, I also think that it would be good to check if there are cases
where this information is significant enough that its inclusion makes
sense. In the top message of the thread, the logs you showed refer to
operations that represent 1/2ms worth of checkpoint. So, if in most
cases this is going to be very quick, adding it to the logs won't
matter because that's not a performance bottleneck. Perhaps that's
something the patch that works on progress reporting for checkpoint
is able to track?
--
Michael