AIt can be increased up to the value of the SGA_MAX_SIZE parameter.
BIncreasing the value of the SGA_TARGET parameter distributes the increased memory among all the Autotuned components.
CReducing the value of the SGA_TARGET parameter deallocates memory from both autotuned and Manually sized components.
DIncreasing the value of SGA_TARGET up to the value of SGA_MAX_SIZE disables the automatic shared Memory management feature.