[PostgreSQL] See SQL queries (without restarting the server!)

1. In postgresql.conf (probably under /etc/postgres/...), uncomment log_statement and set to 'all'

log_statement = 'all'

2. To reload config, sending SIGHUP to postgres server by going to psql shell and execute:

select pg_reload_conf();

    There's an another way to send SIGHUP, please refer to the link below

3. Observe the queries at postgresql.log (probably under /var/log/...)
4. To disable, comment out log_statement and reload config again

log_statement, reloading postgresql config

Credit: http://stackoverflow.com/a/8208376