select 
  substr(file_name, instr(file_name, '/', -1)+1, 30) "File",
  substr(ow||'.'||sn||nvl2(pn, '.'||pn, null), 1, 40) "Segment",
  st "Type",
  to_char(bl*block_size/1024/1024, '99,990.99') "Size (Mb)",
  to_char((bi+bl)*block_size/1024/1024, '99,990.99') "Last (Mb)",
  (bi+bl)*block_size/1024 "Last (kb)"
from (
  select file_id,
  max(owner) over (partition by file_id order by block_id desc) ow,
  max(segment_name) over (partition by file_id order by block_id desc) sn,
  max(partition_name) over (partition by file_id order by block_id desc) pn,
  max(segment_type) over (partition by file_id order by block_id desc) st,
  max(block_id) over (partition by file_id order by block_id desc) bi,
  max(blocks) over (partition by file_id order by block_id desc) bl,
  row_number() over (partition by file_id order by block_id desc) rn
  from dba_extents
  where tablespace_name=upper('&Tablespace')
) a, dba_data_files df, dba_tablespaces ts
where rn=1 and a.file_id=df.file_id and df.tablespace_name=ts.tablespace_name;