On Wed, 6 Feb 2019 at 18:30, Amit Khandekar <amitdkhan...@gmail.com> wrote: > > On Mon, 21 Jan 2019 at 08:31, Andres Freund <and...@anarazel.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
prefetch_xid_horizon_scan_v1.patch
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