Re: Parallel Seq Scan vs kernel read ahead

From: Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
To: Thomas Munro <thomas(dot)munro(at)gmail(dot)com>
Cc: David Rowley <dgrowleyml(at)gmail(dot)com>, "k(dot)jamison(at)fujitsu(dot)com" <k(dot)jamison(at)fujitsu(dot)com>, Robert Haas <robertmhaas(at)gmail(dot)com>, Ranier Vilela <ranier(dot)vf(at)gmail(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Parallel Seq Scan vs kernel read ahead
Date: 2020-07-23 11:00:43
Message-ID: CAA4eK1Kc50q1QY4=CXt=cnd4Y7CU-=8mUAg=cpm-PkYoFaWM0w@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

On Wed, Jul 22, 2020 at 10:03 AM Thomas Munro <thomas(dot)munro(at)gmail(dot)com> wrote:
>
> On Wed, Jul 22, 2020 at 3:57 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> > Yeah, that is true but every time before the test the same amount of
> > data should be present in shared buffers (or OS cache) if any which
> > will help in getting consistent results. However, it is fine to
> > reboot the machine as well if that is a convenient way.
>
> We really should have an extension (pg_prewarm?) that knows how to
> kick stuff out PostgreSQL's shared buffers and the page cache
> (POSIX_FADV_DONTNEED).
>

+1. Such an extension would be quite helpful for performance benchmarks.

--
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Daniel Gustafsson 2020-07-23 11:29:42 Re: Compatible defaults for LEAD/LAG
Previous Message Amul Sul 2020-07-23 10:56:35 Re: [Patch] ALTER SYSTEM READ ONLY