Message-ID: <8039d3e65e099b6046a48209fd1c194b1493fd8d.camel@cybertec.at>
Subject: Re: Fillfactor effectiveness on existing table
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Durgamahesh Manne <maheshpostgres9@gmail.com>, pgsql-general
	 <pgsql-general@lists.postgresql.org>
Date: Tue, 10 Feb 2026 19:31:08 +0100
In-Reply-To: <CAJCZko+BFu4c4moqA5kMoJx3776xdYfEsxJQVNu_YYgrBmsCyQ@mail.gmail.com>
References: 
	<CAJCZko+BFu4c4moqA5kMoJx3776xdYfEsxJQVNu_YYgrBmsCyQ@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
User-Agent: Evolution 3.58.2 (3.58.2-1.fc43) 
MIME-Version: 1.0
Archived-At: <https://www.postgresql.org/message-id/8039d3e65e099b6046a48209fd1c194b1493fd8d.camel%40cybertec.at>
Precedence: bulk

On Tue, 2026-02-10 at 21:25 +0530, Durgamahesh Manne wrote:
> I added fillfactor with less than 100 to existing table then ran vacuum f=
ull to take effect=C2=A0
>=20
> How to ensure the applied fillfactor is working successfully=C2=A0
>=20
> A ratio of hot updates in catalog table should higher than value of n_dea=
d_tup or n_tup_upd? Or what ?

Run

  SELECT n_tup_upd, n_tup_hot_upd
  FROM pg_stat_all_tables
  WHERE relname =3D 'your table';

Then wait for an hour and run the query again.

See how much "n_tup_upd" and "n_tup_hot_upd" increased in that hour.
If the increase is about the same for both, almost all of your UPDATEs
are HOT.

Yours,
Laurenz Albe