oracle automatic memory management

Note that after resetting various parameters I played with I realized that finally Oracle has implemented the human-friendly way for resetting parameters in SPFILE:

Sys@Lin11g> alter system reset pga_aggregate_target;  

System altered.  

Sys@Lin11g> alter system reset sga_target;  

System altered.  

…no scope=spfile sid=’*’ is needed. This resets the parameter in spfile only, the values in memory persist.