ps -aef | grep postgres
postgres  1029     1  0 Nov25 ?        00:00:03 /usr/lib/postgresql/9.1/bin/postgres -D /var/lib/postgresql/9.1/main -c config_file=/etc/postgresql/9.1/main/postgresql.conf
postgres  1315  1029  0 Nov25 ?        00:00:05 postgres: writer process
postgres  1316  1029  0 Nov25 ?        00:00:05 postgres: wal writer process
postgres  1317  1029  0 Nov25 ?        00:00:00 postgres: stats collector process
root     26530 25497  0 02:39 pts/1    00:00:00 grep --color=auto postgres