Oracle ADW Memory Tips
Oracle ADW 内存相关的 Tips
ADW 内存相关
ADW内存大小与ocpu个数相关，成比例
`ADW: sga_target=3.4GB pga_aggregate_target=5.1GB / 1ocpu`
SQL> !date
Thu Apr 18 03:45:27 GMT 2019
SQL>
SQL> show parameter cpu_count
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
cpu_count integer 1
SQL> show parameter sga_target
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
sga_target big integer 3400M
SQL> show parameter pga_aggregate_target
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
pga_aggregate_target big integer 5100M
SQL>
能手动刷新flushcache吗？
SQL> show user;
USER is "ADMIN"
SQL> alter system flush buffer_cache;
alter system flush buffer_cache
*
ERROR at line 1:
ORA-01031: insufficient privileges
SQL>
要刷新cache的话，可以通过重启instance就行刷cache
另外ADW默认result_cache是开启的,在测试评估中可以通过 /*+ NO_RESULT_CACHE */ 的hint方式执行sql对比有无result_cache的执行结果。ATP则没有设置
SQL> show parameter result_cache
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
client_result_cache_lag big integer 3000
client_result_cache_size big integer 0
result_cache_max_result integer 1
result_cache_max_size big integer 10M
result_cache_mode string FORCE
result_cache_remote_expiration integer 0
SQL>
ADW可以使用 In-Memory Columnar Caching(DBIM)
从18c开始，只要设置inmemory_size参数大小即可是存储服务器上的In-Memory Columnar Caching
注意是在Storage Server上，并不是DB Server!参考如下文档
7.9 Enabling or Disabling In-Memory Columnar Caching on Storage Servers
Have a good work&life! 2019/03 via LinHong