O/P of the query you provided :

KSPPINM KSPPSTVL KSPPDESC
---------------------------------------------------------------- -------------------- --------------------------------------------------
pga_aggregate_target 314572800 Target size for the aggregate PGA memory consumed
by the instanc

_pga_max_size 209715200 Maximum size of the PGA memory for one process
_smm_max_size 15360 maximum work area size in auto mode (serial)
_smm_px_max_size 92160 maximum work area size in auto mode (global)


So, I guess I was wrong in mentioning pga_aggregate_target value in original post. But, that was a value we had set and did not make a difference.

Thanks.