public inbox for [email protected]
help / color / mirror / Atom feedFrom: Michael Paquier <[email protected]>
To: Japin Li <[email protected]>
Cc: Fujii Masao <[email protected]>
Cc: wenhui qiu <[email protected]>
Cc: pgsql-hackers <[email protected]>
Cc: John Naylor <[email protected]>
Cc: Christoph Berg <[email protected]>
Subject: Re: WAL compression setting after PostgreSQL LZ4 default change
Date: Wed, 8 Jul 2026 07:26:34 +0900
Message-ID: <[email protected]> (raw)
In-Reply-To: <SY7PR01MB1092134E0AD4108661A3A65F8B6F42@SY7PR01MB10921.ausprd01.prod.outlook.com>
References: <CAGjGUAL1b=Mwd1SCvLbo+fivEr9KDpFcu4jmqKCZXwT=6CiiGQ@mail.gmail.com>
<[email protected]>
<CAHGQGwGv8FLvOkTm3dpTsvt70puYpzKOmq3-YQSOpDCdZ8gyaQ@mail.gmail.com>
<SY7PR01MB1092134E0AD4108661A3A65F8B6F42@SY7PR01MB10921.ausprd01.prod.outlook.com>
On Fri, Jul 03, 2026 at 04:38:06PM +0800, Japin Li wrote:
> On Fri, 03 Jul 2026 at 11:58, Fujii Masao <[email protected]> wrote:
>> On Wed, Jul 1, 2026 at 8:45 AM Michael Paquier <[email protected]> wrote:
>>>
>>> On Tue, Jun 30, 2026 at 06:25:09PM +0800, wenhui qiu wrote:
>>> > The recent PostgreSQL commit changes the default TOAST compression to lz4
>>> > when LZ4 support is available, based on the rationale that LZ4 is generally
>>> > more efficient than pglz in terms of CPU usage and compression
>>> > ratio. Given that, should we also consider changing the default
>>> > compression method used by wal_compression = on from pglz to lz4?
>>>
>>> "on" is just a backward-compatible value, so we could let it as-is.
>>
>> Yes, so +1 to leaving "on" as it is. Making its meaning depend on
>> the build options seems very confusing. Users who want lz4 or zstd
>> can simply specify those methods explicitly instead of using "on".
>
> Understood. I'll withdraw this from the CommitFest.
I disagree. The whole argument is that most users don't bother
changing the defaults. Here, a change between lz4/zstd and pglz is
like day and night; folks are going to see improvements all the time
if we switch to a better default when we can, in terms of CPU, memory
and IO.
--
Michael
Attachments:
[application/pgp-signature] signature.asc (833B, ../[email protected]/2-signature.asc)
download
view thread (12+ messages) latest in thread
reply
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: [email protected]
Cc: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
Subject: Re: WAL compression setting after PostgreSQL LZ4 default change
In-Reply-To: <[email protected]>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox