SQL> select * from v$version;

BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
PL/SQL Release 11.2.0.4.0 - Production
CORE    11.2.0.4.0      Production
TNS for Linux: Version 11.2.0.4.0 - Production
NLSRTL Version 11.2.0.4.0 - Production

SQL> show parameter target

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
archive_lag_target                   integer     0
db_flashback_retention_target        integer     1440
fast_start_io_target                 integer     0
fast_start_mttr_target               integer     0
memory_max_target                    big integer 512M
memory_target                        big integer 512M
parallel_servers_target              integer     32
pga_aggregate_target                 big integer 0
sga_target                           big integer 0
SQL> select pga_alloc_mem/1024/1024 as pga_alloc_mb, pga_max_mem/1024/1024 as pga_max_mb from v$process where addr = (select paddr from v$session where sid = sys_context('userenv', 'sid'));

PGA_ALLOC_MB PGA_MAX_MB
------------ ----------
  2.11863518 2.61863518

SQL> !cat pga.sql
declare
  type t_dummy is table of char(4000);
  l_dummy t_dummy := t_dummy();
begin
  for i in 1..500000
  loop
    l_dummy.extend;
        l_dummy(l_dummy.count) := 'A';
  end loop;
end;
/

SQL> @pga

PL/SQL procedure successfully completed.

SQL> select pga_alloc_mem/1024/1024 as pga_alloc_mb, pga_max_mem/1024/1024 as pga_max_mb from v$process where addr = (select paddr from v$session where sid = sys_context('userenv', 'sid'));

PGA_ALLOC_MB PGA_MAX_MB
------------ ----------
  1.99363518 2605.30614

SQL>