Re: [Patch] Optimize dropping of relation buffers using dlist

On Wed, Jan 13, 2021 at 7:39 AM Kyotaro Horiguchi
<horikyota(dot)ntt(at)gmail(dot)com> wrote:
>
> At Tue, 12 Jan 2021 08:49:53 +0530, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote in
> > On Fri, Jan 8, 2021 at 7:03 AM Kyotaro Horiguchi
> > <horikyota(dot)ntt(at)gmail(dot)com> wrote:
> > >
> > > At Thu, 7 Jan 2021 09:25:22 +0000, "k(dot)jamison(at)fujitsu(dot)com" <k(dot)jamison(at)fujitsu(dot)com> wrote in:
> > > > > Thanks for the detailed tests. NBuffers/32 seems like an appropriate
> > > > > value for the threshold based on these results. I would like to
> > > > > slightly modify part of the commit message in the first patch as below
> > > > > [1], otherwise, I am fine with the changes. Unless you or anyone else
> > > > > has any more comments, I am planning to push the 0001 and 0002
> > > > > sometime next week.
> > > > >
> > > > > [1]
> > > > > "The recovery path of DropRelFileNodeBuffers() is optimized so that
> > > > > scanning of the whole buffer pool can be avoided when the number of
> > > > > blocks to be truncated in a relation is below a certain threshold. For
> > > > > such cases, we find the buffers by doing lookups in BufMapping table.
> > > > > This improves the performance by more than 100 times in many cases
> > > > > when several small tables (tested with 1000 relations) are truncated
> > > > > and where the server is configured with a large value of shared
> > > > > buffers (greater than 100GB)."
> > > >
> > > > Thank you for taking a look at the results of the tests. And it's also
> > > > consistent with the results from Tang too.
> > > > The commit message LGTM.
> > >
> > > +1.
> > >
> >
> > I have pushed the 0001.
>
> Thank you for commiting this.
>

Pushed 0002 as well.

--
With Regards,
Amit Kapila.