Re: Parallel Seq Scan vs kernel read ahead

From: David Rowley <dgrowleyml(at)gmail(dot)com>
To: Thomas Munro <thomas(dot)munro(at)gmail(dot)com>
Cc: Ranier Vilela <ranier(dot)vf(at)gmail(dot)com>, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Parallel Seq Scan vs kernel read ahead
Date: 2020-05-21 21:59:58
Message-ID: CAApHDvp8DYsi+oD1R_WVjhqZRVSRufsUwgSKVyD1HhHHfj5kAQ@mail.gmail.com
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On Thu, 21 May 2020 at 17:06, David Rowley <dgrowleyml(at)gmail(dot)com> wrote:
> For the patch. I know you just put it together quickly, but I don't
> think you can do that ramp up the way you have. It looks like there's
> a risk of torn reads and torn writes and I'm unsure how much that
> could affect the test results here.

Oops. On closer inspection, I see that memory is per worker, not
global to the scan.

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