Re: pgsql: Track block level checksum failures in pg_stat_database

On Tue, Apr 30, 2019 at 11:56 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> Julien Rouhaud <rjuju123@gmail.com> writes:
> > On Tue, Apr 30, 2019 at 6:33 PM Tomas Vondra
> > <tomas.vondra@2ndquadrant.com> wrote:
> >> It seems this commit forgot to add PgStat_MsgChecksumFailure to the
> >> PgStat_Msg union.
>
> > Oops, indeed.  That's embarrassing.  Trivial fix attached if that helps.
>
> Seems like this exposes a generic weakness in the way pgstat.c is coded.
> I'm inclined to adjust the switch logic in PgstatCollectorMain along
> the lines of
>
> -                    pgstat_recv_inquiry((PgStat_MsgInquiry *) &msg, len);
> +                    pgstat_recv_inquiry(&msg.msg_inquiry, len);
>
> so that you *couldn't* forget to extend the union, as long as you
> followed the existing code's style.

Right, I was also wondering why there wasn't compile error in such
case.  I'll send an updated patch tomorrow, as I usually regret any
code I write after midnight.