3.8 Create and Manage Database Users
                 --------------------------------

- Controlling user access.

  - Monitoring user sessions

    - V$SESSION view

    - Monitoring idle time

      >>>> Begin of script

      rem****************************************************
      rem****************************************************
      rem              IDLE_TIME MONITOR SCRIPT
      rem****************************************************
      rem****************************************************
      rem
      rem
      rem   This script provides an easy way for dba to
      rem   monitor session idle times. The output of
      rem   the script shows the sid for each session
      rem   running against the database, the last time
      rem   this session was active (including date and
      rem   time), the current time and the amount of
      rem   time (in seconds as well as minutes) elapsed
      rem   since the session became inactive.  This
      rem   script is written to be run from the sys
      rem   account in sqlplus.
      rem
      column sid format 999
      column last format a22 heading "Last non-idle time"
      column curr format a22 heading "Current time"
      column secs format 99999999.999 -
             heading "idle-time |(seconds)"
      column mins format 999999.99999
             heading "idle-time |(minutes)"
      select sid,
             to_char((sysdate - (hsecs - value)/(100*60*60*24)),
                'dd-mon-yy hh:mi:ss') last,
             to_char(sysdate, 'dd-mon-yy hh:mi:ss') curr,
             (hsecs - value)/(100) secs,
             (hsecs - value)/(100*60) mins
             from V$TIMER, V$SESSTAT
             where statistic# =
                   (select statistic# from V$STATNAME
                    where Name = 'process last non-idle time');
      >>>> End of script

- Managing database security for users.

- Creating users. Altering users. Dropping an existing user.
  Monitoring users. Killing user's session.

- Controlling database system resources. Managing profiles. View
  profile information.