As Dave described in his original email on this topic, we'd like to avoid recycling WAL files since that can cause performance issues when we have a read-modify-write on a file that has dropped out of the cache.
I have implemented a small change to allow WAL recycling to be disabled. It is visible at:
This looks so simple, yet so beneficial. Thanks for making it. Is there some other mechanism that already cleans out the old unneeded WAL files? I recall there is something that does it when you start up after changing the number of files to keep, but I don't recall if that is tested over some loop regularly.
Is there some way to make it auto-detect when it should be enabled? If not, please document that it should be used on ZFS and any other file system with CoW properties on files.
