On 12/9/18 5:24 PM, Ron wrote: > On 12/09/2018 01:10 PM, Stephen Frost wrote: >> >> You can address that risk by enabling archive_timeout, which will make >> PostgreSQL archive the WAL file even if it isn't full after a certain >> amount of time, reducing the potential data loss window. > > I thought checkpoint_timeout forced a WAL switch. Checkpoints do not automatically switch WAL. archive_timeout is the way to go. Postgres >= 9.5 will mostly zero the remainder of the WAL and Postgres >= 11 will entirely zero it. Either way, compression works well. For production systems I generally use archive_timeout=900 so a segment is archived every 15 minutes when there is not enough activity to force a switch naturally. Note that if there is *zero* activity then there in no need for a WAL switch but some older versions would do so anyway if wal_level=hot_standby. We fixed that in Postgres 10. Regards, -- -David david@xxxxxxxxxxxxx
