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Date: Thu, 24 Jul 2025 16:03:34 -0600
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Subject: Re: PostgreSQL on S3-backed Block Storage with Near-Local Performance
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From: Jeff Ross <jross@openvistas.net>
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On 7/24/25 13:50, Pierre Barre wrote:

> It’s not “safe” or “unsafe”, there’s mountains of valid workloads which don’t require synchronous_commit. Synchronous_commit don’t make your system automatically safe either, and if that’s a requirement, there’s many workarounds, as you suggested, it certainly doesn’t 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 = off, wal_init_zero = off and wal_recycle = off.
>> Bingo.  That's why it's fast (synchronous_commit = 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
>> --
This then begs the obvious question of how fast is this with 
synchronous_commit = on?