Re: pg_stat_wal: tracking the compression effect

At Fri, 26 Aug 2022 11:55:27 +0900 (JST), Kyotaro Horiguchi <horikyota(dot)ntt(at)gmail(dot)com> wrote in
> At Thu, 25 Aug 2022 16:04:50 +0900, Ken Kato <katouknl(at)oss(dot)nttdata(dot)com> wrote in
> > Accumulating the values, which indicates how much space is saved by
> > each compression (size before compression - size after compression),
> > and keep track of how many times compression has happened. So that one
> > can know how much space is saved on average.
>
> Honestly, I don't think its useful much.
> How about adding them to pg_waldump and pg_walinspect instead?
>
> # It further widens the output of pg_waldump, though..

Sorry, that was apparently too short.

I know you already see that in per-record output of pg_waldump, but
maybe we need the summary of saved bytes in "pg_waldump -b -z" output
and the corresponding output of pg_walinspect.

regards.

--
Kyotaro Horiguchi
NTT Open Source Software Center