Oracle 11g 只要設定 memory 就可以了。不需要單獨對 sga_max_size 進行設定，

設定memory_max_target、memory_target 一般原則是 物理記憶體的1/2。設好了重啟例項，sga_max_size 將自動變成memory_max_target設定的值

memory_max_target

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SQL> show parameter sga

NAME TYPE VALUE

------------------------------------ ----------- ------------------------------

lock_sga boolean FALSE

pre_page_sga boolean FALSE

sga_max_size big integer 512M

sga_target big integer 512M

SQL>

SQL> show parameter memory

NAME TYPE VALUE

------------------------------------ ----------- ------------------------------

hi_shared_memory_address integer 0

memory_max_target big integer 0

memory_target big integer 0

shared_memory_address integer 0

SQL>

sql>alter system set memory_max_target = 15G scope=spfile;

sql>alter system set memory_target = 15G scope=spfile;

shutdown immediate

startup

SQL> show parameter memory

NAME TYPE VALUE

------------------------------------ ----------- ------------------------------

hi_shared_memory_address integer 0

memory_max_target big integer 15G

memory_target big integer 15G

shared_memory_address integer 0

SQL>