Re: WAL compression setting after PostgreSQL LZ4 default change

On Fri, 03 Jul 2026 at 11:58, Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
> On Wed, Jul 1, 2026 at 8:45 AM Michael Paquier <michael(at)paquier(dot)xyz> 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.

> Regards,
>
> --
> Fujii Masao

--
Regards,
Japin Li
ChengDu WenWu Information Technology Co., Ltd.