Re: PostgreSQL on S3-backed Block Storage with Near-Local Performance

It’s not “safe” or “unsafe”, there’s mountains of valid workloads which don’t require synchronous_commit.
Synchronous_commitdon’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
> --