Re: fix stats_fetch_consistency value in postgresql.conf.sample

On Mon, Sep 26, 2022 at 05:29:58PM +0900, Kyotaro Horiguchi wrote:
> At Sat, 17 Sep 2022 23:53:07 -0500, Justin Pryzby <pryzby(at)telsasoft(dot)com> wrote in
> > This is an alternative implementation, which still relies on adding the
> > GUC_DYNAMIC, flag but doesn't require adding a new, sql-accessible
> > function to convert the GUC to a pretty/human display value.
>
> Thanks!
>
> I'm not sure shared_buffer is GUC_DYNAMIC_DEFAULT, and we need to read

It's set during initdb.

> postgresql.conf.sample using SQL, but +1 for the direction.
>
> + AND NOT (sc.sample_value ~ '^0' AND current_setting(name) ~ '^0') -- zeros may be written differently
> + AND NOT (sc.sample_value='60s' AND current_setting(name) = '1min') -- two ways to write 1min
>
> Mmm. Couldn't we get away from that explicit exceptions?

Suggestions are welcomed.

Rebased the patch.

I also split the flag into DEFAULTS_COMPILE and DEFAULTS_INITDB, since
that makes it easier to understand what the flags mean and the intent of
the patch. And maybe allows fewer exclusions in patches like Peter's,
which I think would only want to exclude compile-time defaults.

--
Justin