usnsql.sql Displays information about UNDO segments with sql statements

select /*+ ALL_ROWS */ a.usn, a1.name, a.extents, a.hwmsize, a.status usn_status,

b.start_date, b.status tx_status,

c.sid, c.sql_id,

d.sql_text

from v$rollstat a, v$rollname a1, v$transaction b, v$session c, v$sqlarea d

where a.usn = b. xidusn

and a.usn = a1.usn

and b.ses_addr = c.saddr

and c.sql_id = d.sql_id;