MIME-Version: 1.0
References: 
 <CALdSSPi3Gh08NtcCn44uVeUAYGOT74sU6uei_06qUTa5rMK43g@mail.gmail.com>
 <CAExHW5s-StFwDpZBeiikvdnrBBr0s+2jJTZRv3Hh914T4C6Euw@mail.gmail.com>
 <CA+QeY+AmRSSJU8GKJ1uNVe2ps8GTONXpioYR7gEz91_prKR6sw@mail.gmail.com>
 <aKQac2ZrY4UWBORR@paquier.xyz>
 <CA+QeY+AwWV=g8z1eDE7OGHxKBer18gVER7nD+SnfhqLmiL7NOA@mail.gmail.com>
 <a5f1b794396a79d69ec70f5eaa7bdaf3@oss.nttdata.com>
 <d8a16af85820dddd9495442cc23111d0@oss.nttdata.com>
 <CAExHW5sUU1+Vq9oG6x=u85W7Obr-dPfAc7rQtaN-LJw5uufuMA@mail.gmail.com>
 <CA+QeY+DLsjj4RxY-Z2wRC-sYCeFxuPSd8zSkt4Nvs==YV6GP6w@mail.gmail.com>
 <CAExHW5tDxjXKcP0XuUZXb_UbpAs_oQ29HyOtvL0xf7dCkk5ypw@mail.gmail.com>
 <CA+QeY+A2B7mjWc8kkieNS_nxNyTeZpTzi4Ue+vtHzkmfFxO-8Q@mail.gmail.com>
 <CAExHW5sFtNduYEnyGhQOb=xiLrbkvwE0merhpZA5pNqcNzBbmw@mail.gmail.com>
 <CA+QeY+C38cgqesZi1Tt92=D6rw_RzCV5yKhoDe5eFLtQ9RQB_Q@mail.gmail.com>
 <29f9e7abc90c3a4fe4a44026141c0d6c@oss.nttdata.com>
 <CABPTF7WfTDdhZbHBgoqo=uGP_DZO-xO1bX5BfkwjgHK9jU+tOA@mail.gmail.com>
 <95850ce1-2d5e-4271-92ea-c2a02e36b303@vondra.me>
 <CA+QeY+Aja_=j1EuY87L06KaPO4EJqqkS4B+Vg9AsWnGM1d_VRA@mail.gmail.com>
 <CAExHW5vDJ526OXv+Hk-=TxPoiL7RR+k+xSF2tyNqtaJHC5aoDQ@mail.gmail.com>
 <CA+QeY+CF2q2M51k5t4rZZ2SNeEq8ORf3Dr8T1+jm72VsHRJfjw@mail.gmail.com>
In-Reply-To: 
 <CA+QeY+CF2q2M51k5t4rZZ2SNeEq8ORf3Dr8T1+jm72VsHRJfjw@mail.gmail.com>
From: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Date: Mon, 8 Dec 2025 10:10:16 +0530
Message-ID: 
 <CAExHW5shToKbeiw1eRGeiSyVeCYZUJyw2KUtBKYFn0J3dCGzbA@mail.gmail.com>
Subject: Re: [Proposal] Expose internal MultiXact member count function for
 efficient monitoring
To: Naga Appani <nagnrik@gmail.com>
Cc: Tomas Vondra <tomas@vondra.me>, Xuneng Zhou <xunengzhou@gmail.com>,
	torikoshia <torikoshia@oss.nttdata.com>,
 Michael Paquier <michael@paquier.xyz>,
	Kirill Reshke <reshkekirill@gmail.com>, pgsql-hackers@postgresql.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Archived-At: 
 <https://www.postgresql.org/message-id/CAExHW5shToKbeiw1eRGeiSyVeCYZUJyw2KUtBKYFn0J3dCGzbA%40mail.gmail.com>
Precedence: bulk

On Sat, Dec 6, 2025 at 11:23=E2=80=AFPM Naga Appani <nagnrik@gmail.com> wro=
te:
>
> Hi Ashutosh,
>
> Thanks for the review!
>
> I agree - comparing the exposed members_size against the documented
> thresholds is sufficient for monitoring purposes.
>
> This aligns with the approach taken in v11: exposing the current usage in
> a way consistent with other PostgreSQL counters (e.g., XIDs, OIDs), witho=
ut
> introducing user-visible remaining-capacity calculations whose behavior i=
s
> inconsistent and difficult to interpret externally. In the same spirit, I
> removed oldest_offset: as we discussed, it is internal and does not
> provide an actionable signal to users.
>
> If this addresses the concerns raised so far, I would appreciate
> consideration in moving v11 forward for commit.

The patch at [1] changes the function used to fetch mxid related
information. With that we will get rid of awkwardness around
non-availability of the statistics. It's better to wait for those
changes to get committed before moving this forward.

--=20
Best Wishes,
Ashutosh Bapat