From dc8efd61d929153d185cdf9e842fe7d708b2e761 Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Thu, 21 Aug 2025 13:25:52 +0900 Subject: [PATCH] doc: Improve description of wal_compression The description of this GUC provides a list of the situations where full-page writes are generated. However, it is not completely exact, mentioning only the cases where full_page_writes=on or base backups. It is possible to generate full-page writes in more situations than these two, making the description confusing as it implies that no other cases exist. The description is slightly reworded to take into account that other cases are possible, without mentioning them directly to minimize the maintenance burden should FPWs be generated in more contexts in the future. Author: Jingtang Zhang Reviewed-by: Andrey Borodin Reviewed-by: Xuneng Zhou Discussion: https://postgr.es/m/CAPsk3_CtAYa_fy4p6=x7qtoutrdKvg1kGk46D5fsE=sMt2546g@mail.gmail.com Backpatch-through: 13 --- doc/src/sgml/config.sgml | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index 1ec048ac31b..b1d2a9500e9 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -3314,8 +3314,9 @@ include_dir 'conf.d' This parameter enables compression of WAL using the specified compression method. When enabled, the PostgreSQL - server compresses full page images written to WAL when - is on or during a base backup. + server compresses full page images written to WAL (e.g. when + is on, during a base backup, + etc.). A compressed page image will be decompressed during WAL replay. The supported methods are pglz, lz4 (if PostgreSQL -- 2.39.5