Oracle 11G OCP 1Z0-052 43

（43）In your database instance, the STATISTICS_LEVEL initialization parameter is set to BASIC. What is the impact of this setting?

A.Optimizer statistics are collected automatically.

B.Only timed operating system (OS) statistics and plan execution statistics are collected.

C.The snapshots for the Automatic Workload Repository (AWR) are not generated automatically.

D.Snapshots cannot be collected manually by using the DBMS_WORKLOAD_REPOSITORY package.

E.The Oracle server dynamically generates the necessary statistics on tables as part of query optimization.

答案：（C）

解析：

參考《References》中STATISTICS_LEVEL初始化引數

STATISTICS_LEVEL = BASIC會禁用許多重要的統計資訊的收集：

1. AWR快照

2. ADDM

3. 所有server-generated預警

4. 自動SGA記憶體管理

5. 物件層次的統計資訊

6. 端到端的應用程式跟蹤（v$CLIENT_STATS)

7. 資料庫時間分佈統計（V$SESS_TIME_MODEL和V$SYS_TIME_MODEL）

8. 服務層次的統計

9. Buffer cache advisor

10. MTTR advisor

11. Shared Pool size advisor

12. 段層次的統計資訊

13. PGA Target advisor

14. Timed statistics

15. 統計的監控

來自 “ ITPUB部落格 ” ，連結：http://blog.itpub.net/17013648/viewspace-1179255/，如需轉載，請註明出處，否則將追究法律責任。