ECSCDAP1P > @dba_hist_seg_stat_AVERAGE_LOGICAL_READS_PER_MINUTE.sql

DATE                 AVG_GIG_PER_MIN
-------------------- ---------------
2012-06-14 Thursday            821.3
2012-06-15 Friday              754.4
2012-06-16 Saturday            683.0
2012-06-17 Sunday              755.7
2012-06-18 Monday              818.2
2012-06-19 Tuesday             779.9
2012-06-20 Wednesday           873.4 Indexes rebuilt and then
2012-06-21 Thursday            369.3 processing falls the next day
2012-06-22 Friday              343.8
2012-06-23 Saturday            322.7
2012-06-24 Sunday              321.7
2012-06-25 Monday              367.4
2012-06-26 Tuesday             356.3
2012-06-27 Wednesday           358.5
2012-06-28 Thursday            334.8

ECSCDAP1P > list
  1  select to_char(c.BEGIN_INTERVAL_TIME,'YYYY-MM-DD Day') "DATE",
  2  sum(b.LOGICAL_READS_DELTA)*8192/1024/1024/1024/60/24 Avg_GIG_PER_min
  3  from dba_objects a,dba_hist_seg_stat b,sys.wRM$_SNAPSHOT c
  4  where a.object_id=b.OBJ#
  5  and c.snap_id=b.snap_id
  6  and c.begin_interval_time > trunc(sysdate-29)
  7  and c.begin_interval_time < trunc(sysdate)
  8  and b.instance_number=c.instance_number
  9  group by to_char(c.BEGIN_INTERVAL_TIME,'YYYY-MM-DD Day')
 10* order by to_char(c.BEGIN_INTERVAL_TIME,'YYYY-MM-DD Day')