Wiki / Configuration Parameters

This parameter enables compression of WAL using the specified compression method. When enabled, the PostgreSQL server compresses full page images written to WAL (e.g. when full_page_writes 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 was compiled with --with-lz4) and zstd (if PostgreSQL was compiled with --with-zstd). The value on is a historical spelling of pglz. The default value is off. Only superusers and users with the appropriate SET privilege can change this setting. Enabling compression can reduce the WAL volume without increasing the risk of unrecoverable data corruption, but at the cost of some extra CPU spent on the compression during WAL logging and on the decompression during WAL replay.

English manual coverage begins with PostgreSQL 7.4. Source history and runtime observations have their own recorded version boundaries.

boot val

off

category

Write-Ahead Log / Settings

context

superuser

documented

true

enumvals

pglz, lz4, zstd, on, off

extra desc

Unknown

lang

en

max val

Unknown

metadata version

18

min val

Unknown

name

wal_compression

short desc

Compresses full-page writes written in WAL file with specified method.

source

pg-settings-source-snapshot

unit

Unknown

vartype

enum