Query to track session generating redo

set lin 180

set pagesize 2000

col INST_ID format 999

col PROGRAM format A35

col MODULE format A35

col USERNAME format A25

select s.inst_id, s.sid, serial#, program, module, username, value redo_size

from gv$session s, gv$sesstat ss, v$statname sn

where s.sid = ss.sid

and ss.statistic# = sn.statistic#

and sn.name = 'redo size'

and s.inst_id = ss.inst_id

order by redo_size ;