Ubuntu 21.10 has a certain default level of logging by default to:but it does not log everything, only/mostly errors it seems.
/var/log/postgresql/postgresql-13-main.log
Setting:under:and then restarting the server:just works.
log_statement = 'all'
/etc/postgresql/13/main/postgresql.conf
sudo service restart postgresql
Realtime monitoring for long queries instead: stackoverflow.com/questions/8597516/app-to-monitor-postgresql-queries-in-real-time