Oracle Database Discussions

Hi,

I'm investigating a performance issue on my database. What I found out, that a session (lasting for a day) has a lot of undo blocks/records user. I used the following query to identify the session:

select t.start_time,s.sid,s.serial#,s.username,s.status,s.schemaname, t.USED_UBLK "undo blocks used" , t.USED_UREC "undo records used",
s.osuser,s.process,s.machine,s.terminal,s.program,s.module,to_char(s.logon_time,'DD/MON/YY HH24:MI:SS') logon_time
from v$transaction t, v$session s
where s.saddr = t.ses_addr
order by start_time;

Is there a way to list of undo records for a particular transaction (and if possible, to what database block they apply)?

thanks,

Krystian