Note the following parameters settings in your database:
SGA_MAX_SIZE = 1024M
SGA_TARGET = 700M
DB_8K_CACHE_SIZE = 124M
LOG_BUFFER = 200M
You issued the following command to increase the value of DB_8K_CACHE_SIZE:
SQL> ALTER SYSTEM SET DB_8K_CACHE_SIZE=140M;
What would happen?
A. It will fail because DB_8K_CACHE_SIZE parameter cannot be changed dynamically
B. It will be successful only if the memory is available from the auto tuned components
C. It will fail because an increase in DB_8K_CACHE_SIZE cannot be accommodated within SGA_TARGET
D. It will fail because an increase in the DB_8K_CACHE_SIZE cannot be accommodated within SGA_MAX_SIZE
注意：这道题没有说明该数据库的标准块是 8K。 要修改需要使用 db_cache_size其实在大多数我们的数据库标准块的大小为 8K，所以就有了以下不能更新的问题：
ALTER SYSTEM SET DB_8K_CACHE_SIZE=140M
ERROR at line 1:
ORA-32017: failure in updating SPFILE
ORA-00380: cannot specify db_8k_cache_size since 8K is the standard block size
但如果数据库的标准块不是 8K，则是可以更改的。只要满足总的组件不能超过 SGA_MAX_SIZE 就可以了。
按照题意，应该选 D
注：LOG_BUFFER 大小一般为粒度的近似值。