UNDO Tablespace Usage

select a.process, a.program, a.module, a.machine, b.USED_UREC, c.sql_text
from v$sql c, v$session a, v$transaction b
where b.addr = a.taddr
and a.sql_address = c.address
and a.sql_hash_value = c.hash_value
order by b.USED_UREC;

SELECT s.sid , s.username , t.used_ublk
FROM v$transaction t
, v$session s
WHERE 1 = 1
AND t.ses_addr = s.saddr

column username format a15;
column segment_name format a15;

SELECT s.sid , s.username , t.used_ublk, round((t.used_ublk*8)/1024) size_in_MB_8kb_Block_size, round((t.used_ublk*16)/1024
) size_in_MB_16kb_Block_size
FROM v$transaction t
, v$session s
WHERE 1 = 1
AND t.ses_addr = s.saddr;

SELECT distinct rpad(s.sid,3) "SID",S.USERNAME,
E.SEGMENT_NAME,
T.START_TIME "Start",
rpad(T.STATUS,9) "Status",
round((t.used_ublk*8)/1024) "Size(MB)"
--T.USED_UBLK||' Blocks and '||T.USED_UREC||' Records' "Rollback Usage"
FROM DBA_DATA_FILES DF,
DBA_EXTENTS E,
V$SESSION S,
V$TRANSACTION T
WHERE DF.TABLESPACE_NAME = E.TABLESPACE_NAME AND
DF.FILE_ID = UBAFIL AND
S.SADDR = T.SES_ADDR AND
T.UBABLK BETWEEN E.BLOCK_ID AND E.BLOCK_ID+E.BLOCKS AND
E.SEGMENT_TYPE in( 'ROLLBACK','TYPE2 UNDO');