Oracle system statistic average by day

Oracle system statistic average by hour


select      to_char (begin_interval_time, 'day' ) snap_time, avg(value) avg_value
from        dba_hist_sysstat
natural join
            dba_hist_snapshot
where
            stat_name = '&stat_name'
group by    to_char(begin_interval_time, 'day')
order by  
        decode(
        to_char (begin_interval_time, 'day'),
        'sunday', 1,
        'monday', 2,
        'tuesday', 3,
        'wednesday', 4,
        'thursday', 5,
        'friday', 6,
        'saturday', 7
          );

Query uses dba_hist_sysstat view to show average values by day of week.