conn
is a pointer to the connection descriptor that a previous call to mi_open() or mi_server_connect() has established.
lodesc
is the descriptor for the external file or smart large object returned by a previous call to mi_large_object_open(). This descriptor was passed to mi_large_object_map() when the area was mapped.
addr
points to the memory to be unmapped.
Yes
MI_OK
The function was successful.
MI_ERROR
The function was not successful because an argument is invalid.