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Date: Thu, 24 Jul 2025 21:50:58 +0200
From: "Pierre Barre" <pierre@barre.sh>
To: "Nico Williams" <nico@cryptonector.com>
Cc: "Seref Arikan" <serefarikan@gmail.com>, pgsql-general@lists.postgresql.org
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Subject: Re: PostgreSQL on S3-backed Block Storage with Near-Local Performance
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It=E2=80=99s not =E2=80=9Csafe=E2=80=9D or =E2=80=9Cunsafe=E2=80=9D, the=
re=E2=80=99s mountains of valid workloads which don=E2=80=99t require sy=
nchronous_commit. Synchronous_commit don=E2=80=99t make your system auto=
matically safe either, and if that=E2=80=99s a requirement, there=E2=80=99=
s many workarounds, as you suggested, it certainly doesn=E2=80=99t make =
the setup useless.

Best,
Pierre

On Thu, Jul 24, 2025, at 21:44, Nico Williams wrote:
> On Fri, Jul 18, 2025 at 12:57:39PM +0200, Pierre Barre wrote:
>> - Postgres configured accordingly memory-wise as well as with
>>   synchronous_commit =3D off, wal_init_zero =3D off and wal_recycle =3D=
 off.
>
> Bingo.  That's why it's fast (synchronous_commit =3D off).  It's also =
why
> it's not safe _unless_ you have a local, fast, persistent ZIL device
> (which I assume you don't).
>
> Nico
> --