Hi, while investigating something on a cluster with a non-default WAL segment (say 256MB), I've noticed a somewhat surprising behavior of max_wal_size default. While the docs claim the default is 1GB, the actual default depends on the WAL segment size.
For example with the 256MB WAL segments, you end up with this: test=# show max_wal_size ; max_wal_size -------------- 16GB (1 row) This behavior is not entirely new - I've noticed it on 10, before the WAL segment size was moved to initdb (which made it more likely to be used). It's even more surprising there, because it leaves #max_wal_size = 1GB in the sample config, while fc49e24f at least emits the actual value. But I'd say not mentioning this behavior in the docs is a bug. regards -- Tomas Vondra http://www.2ndQuadrant.com PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
