Hi all, I'd like to see if I get it right about pg_wal: it grows up to pretty much max_wal_size, at which point a checkpoint is triggered. If the server triggers a timed checkpoint before the pg_wal is at max_wal_size, the system recycles the wals thus keeping the pg_wal size lower than max_wal_size. Is this correct? In particular, what is in simple words, the discrimination between recycling a segment and creating a new one?
% sudo du -hs $PGDATA/pg_wal/ 273M /postgres/13/data/pg_wal/ % psql -U postgres -c "show max_wal_size;" -c "show checkpoint_timeout;" max_wal_size -------------- 1GB (1 riga) checkpoint_timeout -------------------- 5min (1 riga) and from the last log checkpoint entry: 2021-07-13 02:48:10.492 EDT [2424] LOG: checkpoint starting: time 2021-07-13 02:50:44.515 EDT [2424] LOG: checkpoint complete: wrote 9170 buffers (28.0%); 0 WAL file(s) added, 0 removed, 13 recycled; write=148.878 s, sync=1.889 s, total=154.023 s; sync files=42, longest=0.109 s, average=0.045 s; distance=217376 kB, estimate=217376 kB Thanks, Luca
