Identifying Who Is Using the Temporary Tablespace

select s.sid || ',' || s.serial# sid_serial, s.username,

o.blocks * t.block_size / 1024 / 1024 mb_used, o.tablespace,

o.sqladdr address, h.hash_value, h.sql_text

from v$sort_usage o, v$session s, v$sqlarea h, dba_tablespaces t

where o.session_addr = s.saddr

and o.sqladdr = h.address (+)

and o.tablespace = t.tablespace_name

order by s.sid;