Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1vJVgR-009IUl-0w for pgsql-admin@arkaria.postgresql.org; Thu, 13 Nov 2025 11:40:10 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.96) (envelope-from ) id 1vJVgO-000vjs-03 for pgsql-admin@arkaria.postgresql.org; Thu, 13 Nov 2025 11:40:08 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1vJVgN-000vgX-23 for pgsql-admin@lists.postgresql.org; Thu, 13 Nov 2025 11:40:07 +0000 Received: from relternet-02.developpement-durable.gouv.fr ([194.5.170.14]) by makus.postgresql.org with smtp (Exim 4.96) (envelope-from ) id 1vJSgn-006skD-0A for pgsql-admin@lists.postgresql.org; Thu, 13 Nov 2025 08:28:22 +0000 X-Virus-Scanned: Scan at equipement.gouv.fr DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=developpement-durable.gouv.fr; s=dkim; t=1763022498; bh=iLUMJbqaHx5fVQAefewGDPC4Rgge+o+3kdbQfQkAd0Q=; h=Subject:To:References:From:Date:In-Reply-To:From; b=lEUJsdND2af4mrlz4e/jeU8AncBQjY+dM/32fovpvIa9riO5MeT1z2kqgFKpiYIpS PnRdRFfgDrloimmSUGOTsM2851J1idXn5gBSDFMqzIT1YGD8KtnwJwizOmNKFv+Bzq c7U3HVM7pXmnie031K1MEqwAqs3trT/OVKrxM638= X-decod-Pamela: v1.1.2; le 13/11/2025 09:28:18; + mdf=0; rechld=1; entld=1; balm2=1; vider=0; Subject: Re: pg_dump -j To: pgsql-admin@lists.postgresql.org References: From: =?UTF-8?Q?CONVERS_Yann_=2D_DREAL_Auvergne=2DRh=C3=B4ne=2DAlpes=2FCIDDA?= =?UTF-8?Q?E=2FSIG?= Organization: =?UTF-8?Q?DREAL_Auvergne-Rh=c3=b4ne-Alpes/CIDDAE/SIG?= Date: Thu, 13 Nov 2025 09:28:15 +0100 Message-ID: <922b1f47-ca95-e565-e8a1-1859a472bfa0@developpement-durable.gouv.fr> MIME-Version: 1.0 In-Reply-To: Content-Type: text/html; charset=utf-8 Content-Language: fr Content-Transfer-Encoding: quoted-printable List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk

Hi,

Processeurs is on of the parameters . An other is the outpout:input capacity to write on disks.

I purpose to test your hardware performance with 12 jobs to begin and test less and high to learn which is better.

You can found it approximately with the rate of your speeding writing ratio on disk or outpout of LAN card factoring by job's number.

But testing IRL is more efficient.

We use 7 jobs for =C3=A0 16 nprocs on saving on a master save dedi= cate to with car LAN 1000GhZ for example.

We do it online but without clients traffic and without maintenance operation.

Tell us wich is your better choice!

Bye

Yann

Le 12/11/2025 =C3=A0 17:11, > ronljohnsonjr (par Internet, d=C3=A9p=C3=B4t pgsql-admin-owner+m63745-708218@l= ists.postgresql.org) a =C3=A9crit=C2=A0:

On Wed, Nov 12, 2025 at 10:34=E2=80=AFAM Sam Ste= arns <= sam.stearns@dat.com> wrote:

Howdy,

Would someone be able to advise on the correct setting for the -j option of pg_dump to run the dump in parallel, please?=C2=A0 Is it based on CPU count, or something else?=C2=A0 The output of nproc is 32.

I'd certainly never go beyond=C2=A0$(nproc), but sinc= e COPY generates a lot of IO and compression burns through CPU, it all depends on the system's other workload.=C2=A0 Only you k= now what your system's other workload is when pg_dump is running.

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