10:32:18 SQL> show parameter sga
show parameter sga
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
lock_sga boolean FALSE
pre_page_sga boolean FALSE
sga_max_size big integer 1504M
sga_target big integer 0
10:32:55 SQL> show parameter memory
show parameter memory
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
hi_shared_memory_address integer 0
memory_max_target big integer 8016M
memory_target big integer 8016M
shared_memory_address integer 0
10:33:24 SQL>
10:33:24 SQL> alter system set sga_max_size=1500M scope=spfile;
可以通过sga_max_size调整oracle在启动时所使用的最小sga大小，但该参数不能超过memory_target所指定的大小，如memory_target为1G,那么sga_max_size只能小于或等于1G
否则在启动时会出现以下错误提示：
ORA-00844:Parameter not taking MEMORY_TARGET into account
ORA-00851:SGA_MAX_SIZE 1577058304 cannot be set to more than MEMORY_TARGET 855638016 (816M)