Oracle Session Memory use ora 4030

select
                sum(value)/1024/1024 Mb
             from
                 v$sesstat s, v$statname n
              where
                  n.STATISTIC# = s.STATISTIC# and
                  name = 'session pga memory';

select
   sid,name,trunc(value/1024/1024)
from
   v$statname n,v$sesstat s
where
   n.STATISTIC# = s.STATISTIC# and
   name like 'session%memory%'
order by 3 desc;