'물리적IO관리'에 해당되는 글 1건

set pages 80

set lines 130

col c1 heading 'Average Waits for|Full Scan Read I/O' format 999999.999

col c2 heading 'Average Waits for|Index Read I/O' format 999999.999

col c3 heading 'Percent of| I/O Waits|for scattered|Full Scans' format 999.99

col c4 heading 'Percent of| I/O Waits|for sequential|Index Scans' format 999.99

col c5 heading 'Starting|Value|for|optimizer|index|cost|adj' format 99999

select a.snap_id "Snap",

       sum(a.time_waited_micro)/sum(a.total_waits)/10000 c1,

       sum(b.time_waited_micro)/sum(b.total_waits)/10000 c2,

       (sum(a.total_waits) / sum(a.total_waits + b.total_waits)) * 100 c3,

       (sum(b.total_waits) / sum(a.total_waits + b.total_waits)) * 100 c4,

       (sum(b.time_waited_micro)/sum(b.total_waits)) /

(sum(a.time_waited_micro)/sum(a.total_waits)) * 100 c5

from 

   dba_hist_system_event a, 

   dba_hist_system_event b

where a.snap_id = b.snap_id

and a.event_name = 'db file scattered read'

and b.event_name = 'db file sequential read'

group by a.snap_id

order by 1

/