create table t1 as
select
o.owner          owner,
o.object_name    object_name,
o.subobject_name subobject_name,
o.object_type    object_type,
count(distinct file# || block#)         num_blocks
from
dba_objects  o,
v$bh         bh
where
o.data_object_id  = bh.objd
and
o.owner not in ('SYS','SYSTEM')
and
bh.status != 'free'
group by
o.owner,
o.object_name,
o.subobject_name,
o.object_type
order by
count(distinct file# || block#) desc
;


column c0 heading "Owner" format a12
column c1 heading "Object|Name" format a30
column c2 heading "Object|Type" format a8
column c3 heading "Number of|Blocks in|Buffer|Cache" format 99,999,999
column c4 heading "Percentage|of object|blocks in|Buffer" format 999
column c5 heading "Buffer|Pool"                  format a7
column c6 heading "Block|Size"                   format 99,999

select
t1.owner                                          c0,
object_name                                       c1,
case when object_type = 'TABLE PARTITION' then 'TAB PART'
when object_type = 'INDEX PARTITION' then 'IDX PART'
else object_type end c2,
sum(num_blocks)                                     c3,
(sum(num_blocks)/greatest(sum(blocks), .001))*100 c4,
buffer_pool                                       c5,
sum(bytes)/sum(blocks)                            c6
from
t1,
dba_segments s
where
s.segment_name = t1.object_name
and
s.owner = t1.owner
and
s.segment_type = t1.object_type
and
nvl(s.partition_name,'-') = nvl(t1.subobject_name,'-')
group by
t1.owner,
object_name,
object_type,
buffer_pool
having
sum(num_blocks) > 10
order by
sum(num_blocks) desc
;