Re: [HACKERS] Block level parallel vacuum

On Thu, Jan 16, 2020 at 10:11 AM Mahendra Singh Thalor
<mahi6run@gmail.com> wrote:
>
> On Thu, 16 Jan 2020 at 08:22, Amit Kapila <amit.kapila16@gmail.com> wrote:
> >
> > > 2.
> > > I checked time taken by vacuum.sql test. Execution time is almost same
> > > with and without v45 patch.
> > >
> > > Without v45 patch:
> > > Run1) vacuum                       ... ok 701 ms
> > > Run2) vacuum                       ... ok 549 ms
> > > Run3) vacuum                       ... ok 559 ms
> > > Run4) vacuum                       ... ok 480 ms
> > >
> > > With v45 patch:
> > > Run1) vacuum                       ... ok 842 ms
> > > Run2) vacuum                       ... ok 808 ms
> > > Run3)  vacuum                       ... ok 774 ms
> > > Run4) vacuum                       ... ok 792 ms
> > >
> >
> > I see some variance in results, have you run with autovacuum as off.
> > I was expecting that this might speed up some cases where parallel
> > vacuum is used by default.
>
> I think, this is expected difference in timing because we are adding
> some vacuum related test. I am not starting server manually(means I am
> starting server with only default setting).
>

Can you once test by setting autovacuum = off?  The autovacuum leads
to variability in test timing.


-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com