PGA usage 

ORA-04030: out of process memory when trying to allocate 8216 bytes (PLS PGA hp,PL/SQL STACK)

select s.sid,p.pid,p.spid,p.pga_used_mem, p.pga_alloc_mem  from gv$session s, gv$process p where s.paddr=p.addr

   and  p.pga_alloc_mem >= 10000000

  and s.username like 'PA%'

   order by p.pga_alloc_mem