select * from v$pgastat

NAME | VALUE | UNIT
aggregate PGA target parameter | 74999808 | bytes
aggregate PGA auto target | 62383104 | bytes
global memory bound | 3749888 | bytes
total PGA inuse | 5836800 | bytes
total PGA allocated | 8256512 | bytes
maximum PGA allocated | 8256512 | bytes
total freeable PGA memory | 0 | bytes
PGA memory freed back to OS | 0 | bytes
total PGA used for auto workareas | 0 | bytes
maximum PGA used for auto workareas | 0 | bytes
total PGA used for manual workareas | 0 | bytes
maximum PGA used for manual workareas | 0 | bytes
over allocation count | 0 | null
bytes processed | 9942016 | bytes
extra bytes read/written | 0 | bytes
cache hit percentage | 100 | percent