OCP-1Z0-052-V8 02-40题

最新推荐文章于 2023-04-30 22:58:54 发布

原创最新推荐文章于 2023-04-30 22:58:54 发布 · 89 阅读

0 ·

CC 4.0 BY-SA版权

了解如何在Oracle中手动维护优化器统计信息，防止特定表格及其依赖索引的统计信息被覆盖，直到指定的时间点。通过使用DBMS_STATS包，可以保存、恢复统计信息，甚至将一个数据库的统计信息导出到另一个数据库。

分享一下我老师大神的人工智能教程！零基础，通俗易懂！http://blog.youkuaiyun.com/jiangjunshow

也欢迎大家转载本篇文章。分享知识，造福人民，实现我们中华民族伟大复兴！

40. You have statistics collected for some selected tables. Your requirement is that the statistics for the

tables and all dependent indexes must not be overwritten by further statistics collection until a certain

point of time.

How would you achieve this?

A.Lock statistics for the tables.

B.Change STALE_PERCENT to zero for the tables.

C.Set the TIMED_STATISTICS parameter to TRUE.

D.Set the STATISTICS_LEVEL parameter to BASIC.

E.Set the OPTIMIZER_USE_PENDING parameter statistics to TRUE.

Answer: A

答案解析：

参考：http://docs.oracle.com/cd/E11882_01/server.112/e41573/stats.htm#PFGRF94712

You can maintain optimizer statistics manually using the DBMS_STATS package. For example, you can save and restore copies of statistics. You can export statistics from one database and import those statistics into another database. For example, you can export statistics from a production system to a test system. You can also lock statistics to prevent them from changing.