Обсуждение: pg_dump -j

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

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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 à 16 nprocs on saving on a master save dedicate 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 à 17:11, > ronljohnsonjr (par Internet, dépôt pgsql-admin-owner+m63745-708218@lists.postgresql.org) a écrit :

On Wed, Nov 12, 2025 at 10:34 AM Sam Stearns <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?  Is it based on CPU count, or something else?  The output of nproc is 32.

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

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