Re: PostgreSQL on S3-backed Block Storage with Near-Local Performance - Mailing list pgsql-general

From Pierre Barre
Subject Re: PostgreSQL on S3-backed Block Storage with Near-Local Performance
Date
Msg-id b62bd887-bbb8-4ade-8947-9d2608618b02@app.fastmail.com
Whole thread Raw
In response to Re: PostgreSQL on S3-backed Block Storage with Near-Local Performance  (Jeff Ross <jross@openvistas.net>)
Responses Re: PostgreSQL on S3-backed Block Storage with Near-Local Performance
List pgsql-general
> This then begs the obvious question of how fast is this with
> synchronous_commit = on?

Probably not awful, especially with commit_delay.

I'll try that and report back.

Best,
Pierre

On Fri, Jul 25, 2025, at 00:03, Jeff Ross wrote:
> 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_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
>>> --
> This then begs the obvious question of how fast is this with
> synchronous_commit = on?



pgsql-general by date:

Previous
From: "Pierre Barre"
Date:
Subject: Re: PostgreSQL on S3-backed Block Storage with Near-Local Performance
Next
From: "sivapostgres@yahoo.com"
Date:
Subject: Re: Is there any limit on the number of rows to import using copy command