HI_SHARED_MEMORY_ADDRESS specifies the starting address at runtime of the system global area (SGA). It is ignored on platforms that specify the SGA's starting address at linktime.
On 64-bit platforms, use HI_SHARED_MEMORY_ADDRESS to specify the high-order 32 bits of a 64-bit address. Use SHARED_MEMORY_ADDRESS to specify the low-order 32 bits of the address (see "SHARED_MEMORY_ADDRESS"). If both parameters are 0 or unspecified, the SGA address defaults to a platform-specific location.