sorry, the link was broken.
this was the param.
"wal_compression (boolean)
When this parameter is on, the PostgreSQL server compresses a full
page image written to WAL when full_page_writes is on or during a base
backup. A compressed page image will be decompressed during WAL
replay. The default value is off. Only superusers can change this
setting.
Turning this parameter on 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."
