This script will list the top 10 segments in the database that have the most number of
physical reads against them.
Script can also be changed to query on 'physical writes' instead.
set pagesize 200
col segment_name format a20
col owner format a10
from ( select owner||'.'||object_name as segment_name,object_type,
value as total_physical_reads
where statistic_name in ('physical reads')
order by total_physical_reads desc)
where rownum <=10;