On Wed, May 27, 2020 at 7:09 PM Simon Riggs <si...@2ndquadrant.com> wrote: > On Wed, 27 May 2020 at 04:27, Fujii Masao <masao.fu...@oss.nttdata.com> wrote: >> >> Hi, >> >> The group of wal_init_zero and wal_recycle is WAL_SETTINGS in guc.c, >> but their descriptions are located in "19.6. Replication"/"19.6.1. Sending >> Servers" section. This seems a documentation bug. They should be located >> in "19.5. Write Ahead Log"/"19.5.1. Settings". Thought? > > > +1 > > Why are there two settings for the same thing (COW support)? > Would we really want to allow setting one but not the other?
In the long discussion[1] we decided to invent GUCs that tell you precisely what they do, rather than trying to have a mysterious "COW filesystem mode", given the apparent lack of COW filesystem expertise in the thread (for example: claims, theories and data about ZFS were presented, but do they also apply to BTRFS, APFS, ReFS, ...? I dunno, and no one showed up with more information on that.) [1] https://www.postgresql.org/message-id/flat/CACPQ5Fo00QR7LNAcd1ZjgoBi4y97%2BK760YABs0vQHH5dLdkkMA%40mail.gmail.com
