postgres.git / summary / log / commit / refs

commit    1c58a1bba437c9eee1c0414f2e487d286d1bdacd
Author:   Michael Paquier <michael@paquier.xyz>
Date:     Thu Aug 21 04:25:55 2025 +0000
First released in: 13.23, 14.20, 15.15, 16.11, 17.7, 18.0

    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 <mrdrivingduck@gmail.com>
    Reviewed-by: Andrey Borodin <x4mmm@yandex-team.ru>
    Reviewed-by: Xuneng Zhou <xunengzhou@gmail.com>
    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 9d398d8ee20..eac0051d0d4 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -3169,8 +3169,9 @@ include_dir 'conf.d' This parameter enables compression of WAL using the specified compression method. When enabled, the <productname>PostgreSQL</productname> - server compresses full page images written to WAL when - <xref linkend="guc-full-page-writes"/> is on or during a base backup. + server compresses full page images written to WAL (e.g. when + <xref linkend="guc-full-page-writes"/> is on, during a base backup, + etc.). A compressed page image will be decompressed during WAL replay. The supported methods are <literal>pglz</literal>, <literal>lz4</literal> (if <productname>PostgreSQL</productname> [parent: 818be9b73c94]