oracle 10g常见问题精选

核心提示： SQL> select name, block_size, current_size from v$buffer_pool;name block_size current_size-KEEP 8192 204SQL> Select pool, sum(bytes)/1024/1

SQL> select name, block_size, current_size from v$buffer_pool;
name block_size current_size
-------------------------------------------------------------
KEEP 8192 204
SQL> Select pool, sum(bytes)/1024/1024 as "M bytes" from v$SGASTAT
group by pool;
pool M bytes
-------------------------------------------------
java pool 4
large pool 4
shared pool 84
205.002403
205.002403=buffer cache + log buffer + fixed sga + all others ...

改动java pool的值

SQL> alter system set java_pool_size=20M;
SQL> select name, block_size, current_size,prev_size from v$buffer_pool;
name block_size current_size prev_size
----------------------------------------------------------------------------------------------
KEEP 8192 188 204
SQL> Select pool, sum(bytes)/1024/1024 as "M bytes" from v$SGASTAT
group by pool;
pool M bytes
-------------------------------------------------
java pool 20
large pool 4
shared pool 84
189.002403

可以看出, db_cache_size的值已经被自动调小了.

再把java pool 的值改回去

SQL> alter system set java_pool_size=8M;
SQL> select name, block_size, current_size,prev_size from v$buffer_pool;
name block_size current_size prev_size
-----------------------------------------------------------------------------------
KEEP 8192 188 204
SQL> select name, block_size, current_size,prev_size from v$buffer_pool;
pool M bytes
-------------------------------------------------
java pool 20
large pool 4
shared pool 84
189.002403

这一次, db_cache_size的值没有变化 , JAVA_POOL_SIZE的值也没有变化