psql active connections code example

Example 1: check connections to database postgres

SELECT * FROM pg_stat_activity WHERE datname='db_name';

Example 2: postgresql print sessions using the database

select pid as process_id, 
       usename as username, 
       datname as database_name, 
       client_addr as client_address, 
       application_name,
       backend_start,
       state,
       state_change
from pg_stat_activity;