The logging process

This is an optional process and the default setting is off. We have to set the logging_collector parameter to on to start this process:

cd $PGDATA

Edit the postgresql.conf file and make a few changes:

log_destination = 'stderr'
logging_collector = on
log_directory = 'pg_log'
log_min_duration_statement = 0

[postgres@MyCentOS 9.3]$ pg_ctl restart
waiting for server to shut down.... done
server stopped
server starting
[postgres@MyCentOS 9.3]$ ps f -U postgres
  PID TTY      STAT   TIME COMMAND
 2581 pts/2    S      0:00 -bash
 3201 pts/2    R+     0:00  \_ ps f -U postgres
 2218 pts/1    S+     0:00 -bash
 3186 pts/2    S      0:00 /usr/local/pgsql/bin/postgres
 3187 ?        Ss     0:00  \_ postgres: logger process     
 3189 ?        Ss     0:00  \_ postgres: checkpointer process   
 3190 ?        Ss     0:00  \_ postgres: writer process     
 3191 ?        Ss     0:00  \_ postgres: wal writer process   
 3192 ?        Ss     0:00  \_ postgres: autovacuum launcher process...