Re: POC: Cache data in GetSnapshotData()

On Thu, Mar 3, 2016 at 6:20 AM, Mithun Cy <mithun(dot)cy(at)enterprisedb(dot)com>
wrote:

>
> On Tue, Mar 1, 2016 at 12:59 PM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
> wrote:
> >Don't we need to add this only when the xid of current transaction is
> valid? Also, I think it will be better if we can explain why we need to
> add the our >own transaction id while caching the snapshot.
> I have fixed the same thing and patch is attached.
>
> Some more tests done after that
>
> *pgbench write tests: on 8 socket, 64 core machine.*
>
> /postgres -c shared_buffers=16GB -N 200 -c min_wal_size=15GB -c
> max_wal_size=20GB -c checkpoint_timeout=900 -c maintenance_work_mem=1GB -c
> checkpoint_completion_target=0.9
>
> ./pgbench -c $clients -j $clients -T 1800 -M prepared postgres
>
> [image: Inline image 3]
>
> A small improvement in performance at 64 thread.
>

What if you apply both this and Amit's clog control log patch(es)? Maybe
the combination of the two helps substantially more than either one alone.

Or maybe not, but seems worth checking.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
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