Re: Pluggable Storage - Andres's take

On Wed, 6 Feb 2019 at 18:30, Amit Khandekar <amitdkhan(dot)pg(at)gmail(dot)com> wrote:
>
> On Mon, 21 Jan 2019 at 08:31, Andres Freund <andres(at)anarazel(dot)de> wrote:
> >
> > Hi,
> >
> > (resending with compressed attachements, perhaps that'll go through)
> >
> > On 2018-12-10 18:13:40 -0800, Andres Freund wrote:
> > > On 2018-11-26 17:55:57 -0800, Andres Freund wrote:
> > > > FWIW, now that oids are removed, and the tuple table slot abstraction
> > > > got in, I'm working on rebasing the pluggable storage patchset ontop of
> > > > that.
> > >
> > > I've pushed a version to that to the git tree, including a rebased
> > > version of zheap:
> > > https://github.com/anarazel/postgres-pluggable-storage
>
> I worked on a slight improvement on the
> 0040-WIP-Move-xid-horizon-computation-for-page-level patch . Instead
> of pre-fetching all the required buffers beforehand, the attached WIP
> patch pre-fetches the buffers keeping a constant distance ahead of the
> buffer reads. It's a WIP patch because right now it just uses a
> hard-coded 5 buffers ahead. Haven't used effective_io_concurrency like
> how it is done in nodeBitmapHeapscan.c. Will do that next. But before
> that, any comments on the way I did the improvements would be nice.
>
> Note that for now, the patch is based on the pluggable-storage latest
> commit; it does not replace the 0040 patch in the patch series.

In the attached v1 patch, the prefetch_distance is calculated as
effective_io_concurrency + 10. Also it has some cosmetic changes.

--
Thanks,
-Amit Khandekar
EnterpriseDB Corporation
The Postgres Database Company