Re: [HACKERS] Block level parallel vacuum

On Tue, 28 Jan 2020 at 18:47, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>
> On Tue, Jan 28, 2020 at 12:53 PM Mahendra Singh Thalor
> <mahi6run(at)gmail(dot)com> wrote:
> >
> > > > > > 1.
> > > > > > -P, --parallel=PARALLEL_DEGREE do parallel vacuum
> > > > > >
> > > > > > I think, "do parallel vacuum" should be modified. Without specifying -P, we are still doing parallel vacuum so we can use like "degree for parallel vacuum"
> > > > > >
> > > > >
> > > > > I am not sure if 'degree' makes it very clear. How about "use this
> > > > > many background workers for vacuum, if available"?
> > > >
> > > > If background workers are many, then automatically, we are using them(by default parallel vacuum). This option is to put limit on background workers(limit for vacuum workers) to be used by vacuum process.
> > > >
> > >
> > > I don't think that the option is just to specify the max limit because
> > > that is generally controlled by guc parameters. This option allows
> > > users to specify the number of workers for the cases where he has more
> > > knowledge about the size/type of indexes. In some cases, the user
> > > might be able to make a better decision and that was the reason we
> > > have added this option in the first place.
> > >
> > > > So I think, we can use "max parallel vacuum workers (by default, based on no. of indexes)" or "control parallel vacuum workers"
> > > >
> > >
> > > Hmm, I feel what I suggested is better because of the above explanation.
> >
> > Agreed.
> >
>
> Okay, thanks for the review. Attached is an updated patch. I have
> additionally run pgindent. I am planning to commit the attached
> tomorrow unless I see more comments.

Thank you for committing it!

Regards,

--
Masahiko Sawada http://www.2ndQuadrant.com/
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