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In-Reply-To: <abCpb4VBwmzn9s_P@paquier.xyz>
From: Xuneng Zhou <xunengzhou@gmail.com>
Date: Wed, 11 Mar 2026 10:22:51 +0800
Message-ID: 
 <CABPTF7X9Q8UsKBV6_V2pEQ5rgs=0QMhUjT72m+TkHmJpru7N2Q@mail.gmail.com>
Subject: Re: Streamify more code paths
To: Michael Paquier <michael@paquier.xyz>
Cc: Andres Freund <andres@anarazel.de>,
 pgsql-hackers <pgsql-hackers@lists.postgresql.org>,
	Nazir Bilal Yavuz <byavuz81@gmail.com>
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Hi,

On Wed, Mar 11, 2026 at 7:29=E2=80=AFAM Michael Paquier <michael@paquier.xy=
z> wrote:
>
> On Tue, Mar 10, 2026 at 07:04:37PM -0400, Andres Freund wrote:
> > It might be a good idea to run the benchmarks with debug_io_direct=3Dda=
ta.
> > That'll make them very slow, since the write side doesn't yet use AIO a=
nd thus
> > will do a lot of synchronous writes, but it should still allow to evalu=
ate the
> > gains from using read stream.
>
> Ah, thanks for the tip.  I'll go try that.
>
> > The other thing that's kinda important to evaluate read streams is to t=
est on
> > higher latency storage, even without direct IO.  Many workloads are not=
 at all
> > benefiting from AIO when run on a local NVMe SSD with < 10us latency, b=
ut are
> > severely IO bound when run on a cloud storage disk with 0.5ms - 4ms lat=
ency.
>
> My previous run was on a cloud instance, I don't have access to a SSD
> with this amount of latency locally.
>
> One thing that was standing on is the bloom bitmap case that was
> looking really nice for a large number of rows, so I have applied
> this part.  The rest is going to need a bit more testing to build more
> confidence, as far as I can see.
> --
> Michael

Thanks for pushing that. I=E2=80=99ll update the script with Andres=E2=80=
=99
suggestions and share it shortly.

--=20
Best,
Xuneng