Select from v$session and v$process
select
substr(a.spid,1,9) pid,
substr(b.sid,1,5) sid,
substr(b.serial#,1,5) ser#,
substr(b.machine,1,6) machine,
substr(b.username,1,10) username,
substr(b.osuser,1,8) os_user,
substr(b.program,1,30) program
from v$session b, v$process a
where b.paddr = a.addr and type='USER'
order by spid;