Oracle Average Active Sessions per hour

From A Tour of the AWR Tables

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select    to_char(round(sub1.sample_time, 'HH24'), 'YYYY-MM-DD HH24:MI') as sample_hour,    round(avg(sub1.on_cpu),1) as cpu_avg,    round(avg(sub1.waiting),1) as wait_avg,    round(avg(sub1.active_sessions),1) as act_avg,    round( (variance(sub1.active_sessions)/avg(sub1.active_sessions)),1) as act_var_mean from    ( -- sub1: one row per second, the resolution of SAMPLE_TIME      select         sample_id,         sample_time,         sum(decode(session_state, 'ON CPU', 1, 0))  as on_cpu,         sum(decode(session_state, 'WAITING', 1, 0)) as waiting,         count(*) as active_sessions      from         dba_hist_active_sess_history      where         sample_time > sysdate - (&hours/24)      group by         sample_id,         sample_time    ) sub1 group by    round(sub1.sample_time, 'HH24') order by    round(sub1.sample_time, 'HH24') ;

Linux load average

Examining Linux load average