SELECT s.sid, s.username,
       e.segment_name,
       t.start_time, t.status, t.used_ublk*p.value/1024 usedkb, t.used_urec norecords
  FROM dba_data_files df,
       DBA_EXTENTS E,
       gV$SESSION S,
       gV$TRANSACTION T,
       v$parameter p
 WHERE p.name = 'db_block_size'
   and DF.FILE_ID = E.FILE_ID
   and DF.FILE_ID = UBAFIL
   and S.INST_ID = T.inst_id
   and S.SADDR = T.SES_ADDR
   and T.UBABLK BETWEEN E.BLOCK_ID AND E.BLOCK_ID+e.blocks
   and (e.segment_type = 'ROLLBACK' or e.segment_type like '%UNDO%')
/
