AYou cannot specify MEMORY_TARGET if you explicitly specify SGA_TARGET or PGA_AGGREGATE_TARGET values that are greater than zero in your parameter file.
BOracle can reallocate memory between the SGA and PGA automatically as needed.
CTo use Automatic Memory Management, you must explicitly set both the MEMORY_TARGET and MEMORY_MAX_TARGET parameters in your parameter file.
DYou can set the MEMORY_TARGET parameter to a maximum value of the current SGA size plus the current PGA size.