We can connect to any process with strace, but for demonstrative purposes, we elect to control the environment by watching a connection we directly control. The pg_backend_pid function returns the process ID of the backend process that serves our client, which then lets us monitor its activity on the server.
With the pid of the backend, we can monitor it with the -p parameter to strace, which watches the listed process ID. As we don't want too much output, we elect to execute a very simple query that does not touch the tables, functions, or views. Our output should resemble this:
Process 4200 attached - interrupt to quit recvfrom(11, "Q\0\0\0\16SELECT 1;\0", 8192, 0, NULL, NULL) = 15 sendto(11, "T\0\0\0!\0\1?column?\0\0\0\0\0\0\0\0\0\0\27\0\4\377\377\377\377"..., ...
