11g中改用memory_target

shm     /dev/shm        tmpfs   defaults,size=500M      0 0

把上面的这句写到/etc/fstab中 ,然后mount /dev/shm

oracle中应该修改这些参数
memory_max_target = 500M scope=spfile;
sga_max_size=500M scope=spfile;
memory_target=500m;
sga_target=0;
pga_aggregate_target=0