Segments with highest I/O activity

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

setlinesize 120

col segment_name format a20

col owner format a10

select segment_name,object_type,total_physical_reads

from ( select owner||'.'||object_name as segment_name,object_type,

value as total_physical_reads

from v$segment_statistics

where statistic_name in ('physical reads')

order by total_physical_reads desc)

where rownum <=10;