Re: pgsql: Track block level checksum failures in pg_stat_database

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.

            regards, tom lane