Re: Upgrade from PG12 to PG

On Jul 20, 2023, at 7:23 AM, Jef Mortelle <jefmortelle(at)gmail(dot)com> wrote:
> I use /usr/lib/postgresql15/bin/pg_upgrade -v -p 5431 -P 5432
>
> I takes a lot of time, more than 6 hours

I'm in the middle of a similar database migration myself, but I'm coming from 10.23.

Have you considered adding the --link and --jobs=NN (where NN is the number of CPU cores on your server minus 2 or something like that) to your pg_upgrade command? I wonder if that would speed things up significantly.

Also, if your file system supports reflinks (Linux kernel 4.5 and XFS with reflink support activated or Btrfs or macOS APFS), then use --clone instead of --link.

Good luck,
Ed