Re: design for parallel backup

Hi,

On 2020-04-21 07:18:20 -0400, Robert Haas wrote:
> On Tue, Apr 21, 2020 at 2:44 AM Andres Freund <andres@anarazel.de> wrote:
> > FWIW, I just tested pg_basebackup locally.
> >
> > Without compression and a stock postgres I get:
> > unix                tcp                  tcp+ssl:
> > 1.74GiB/s           1.02GiB/s            699MiB/s
> >
> > That turns out to be bottlenecked by the backup manifest generation.
> 
> Whoa. That's unexpected, at least for me. Is that because of the
> CRC-32C overhead, or something else? What do you get with
> --manifest-checksums=none?

It's all CRC overhead. I don't see a difference with
--manifest-checksums=none anymore. We really should look for a better
"fast" checksum.

Regards,

Andres