[postgres@bogon ~]$ ps ux | grep postgres
postgres  67582  0.4  0.2 272596 13544 ?        Ss   16:53   0:00 /opt/postgresql/bin/postgres -D /opt/pgdata
……
postgres  67590  0.0  0.0 124964  1836 pts/0    S+   16:53   0:00 psql tpch1s
postgres  67591  3.1  0.2 282012 10564 ?        Rs   16:53   0:02 postgres: postgres tpch1s [local] SELECT
postgres  67717 38.1  0.1 280668  7868 ?        Rs   16:54   0:02 postgres: parallel worker for PID 67591   
postgres  67718 26.8  0.1 280700  7800 ?        Rs   16:54   0:01 postgres: parallel worker for PID 67591