[postgres@bogon ~]$ ps ux | grep postgres
postgres  67582  0.5  0.2 272596 13544 ?        Ss   16:53   0:00 /opt/postgresql/bin/postgres -D /opt/pgdata
……  
postgres  67590  0.0  0.0 124964  2068 pts/0    S+   16:53   0:00 psql tpch1s
postgres  67591  8.3  0.2 276208 11252 ?        Rs   16:53   0:09 postgres: postgres tpch1s [local] SELECT
postgres  67741 41.0  0.0 274364  4772 ?        Rs   16:54   0:01 postgres: parallel worker for PID 67591   
postgres  67742 27.6  0.0 274364  4776 ?        Rs   16:54   0:00 postgres: parallel worker for PID 67591   
postgres  67743 37.0  0.0 274364  4772 ?        Rs   16:54   0:01 postgres: parallel worker for PID 67591   
postgres  67744 28.3  0.0 274368  4760 ?        Rs   16:54   0:00 postgres: parallel worker for PID 67591