Greetings,
* Jeff Janes (jeff.janes@gmail.com) wrote:
> On Mon, Nov 4, 2019 at 1:54 AM Amit Kapila <amit.kapila16@gmail.com> wrote:
> > For parallel vacuum [1], we were discussing what is the best way to
> > divide the cost among parallel workers but we didn't get many inputs
> > apart from people who are very actively involved in patch development.
> > I feel that we need some more inputs before we finalize anything, so
> > starting a new thread.
>
> Maybe a I just don't have experience in the type of system that parallel
> vacuum is needed for, but if there is any meaningful IO throttling which is
> active, then what is the point of doing the vacuum in parallel in the first
> place?
With parallelization across indexes, you could have a situation where
the individual indexes are on different tablespaces with independent
i/o, therefore the parallelization ends up giving you an increase in i/o
throughput, not just additional CPU time.
Thanks,
Stephen
