On 2024/07/10 23:18, Nathan Bossart wrote:
On Wed, Jul 10, 2024 at 10:10:30AM -0400, Robert Haas wrote:
On Wed, Jul 10, 2024 at 1:56 AM Fujii Masao <masao.fu...@oss.nttdata.com> wrote:
I'm sure this patch is necessary as a safeguard for WAL summarization.
OTOH, I also think we should apply the patch I proposed earlier
in this thread, which prevents summarize_wal from being enabled
when wal_level is set to minimal. This way, if there's
a misconfiguration, users will see an error message and
can quickly identify and fix the issue. Thought?
I interpreted these emails as meaning that we should not proceed with
that approach:
https://www.postgresql.org/message-id/CAGECzQR2r-rHFLQr5AonFehVP8DiFH+==r2yqdbvunynwxs...@mail.gmail.com
http://postgr.es/m/3253790.1720019...@sss.pgh.pa.us
Yeah. I initially thought this patch might be okay, at least as a stopgap,
but Jelte pointed out a case where it doesn't work, namely when you have
something like the following in the config file:
wal_level = 'minimal'
summarize_wal = 'true'
wal_level = 'logical'
Unless I'm mistaken, the patch works fine in this case. If the check_hook
triggered every time a parameter appears in the configuration file,
it would mistakenly detect wal_level=minimal and summarize_wal=on together
and raise an error. However, this isn't the case. The check_hook is
designed to trigger after duplicate parameters are deduplicated.
Am I missing something?
Regards,
--
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION
