Re: Parallel Seq Scan vs kernel read ahead - Mailing list pgsql-hackers

From Thomas Munro
Subject Re: Parallel Seq Scan vs kernel read ahead
Date
Msg-id CA+hUKG+haG0GUzL_dZjRw5UYs1H1tf9kWt9sqUNXiktSvuEQHw@mail.gmail.com
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In response to Re: Parallel Seq Scan vs kernel read ahead  (Amit Kapila <amit.kapila16@gmail.com>)
Responses Re: Parallel Seq Scan vs kernel read ahead
Re: Parallel Seq Scan vs kernel read ahead
List pgsql-hackers
On Wed, Jul 22, 2020 at 3:57 PM Amit Kapila <amit.kapila16@gmail.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).



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