Re: pg_dump/pg_restore --jobs practical limit?

On Wed, 2023-11-01 at 13:09 -0500, Ron wrote:
> I will "soon" migrate some 1+ TB database from Pg 9.6.24 on RHEL 6 VMs to Pg 
> 14.latest on RHEL 8 VMs.  The VMs have 10Gbps "NICs", SAN-based LUNs managed 
> by LVM, and are all on ESX blades.  nproc count on some is 16 and on others 
> is 32.
> 
> Does anyone have experience as to the point of diminishing returns?
> 
> IOW, can I crank them processes up to --jobs=30, will I see no gain -- or 
> even degradation -- after, for example, --jobs=24?
> 
> This would be for both pg_dump and pg_restore (which would be run on the 
> RHEL 8 VM).

Test, test, test.  Theoretical considerations are pretty worthless, and it
is easy to measure that.

Yours,
Laurenz Albe