您当前的位置：优技教育 > 071考试题库 >

【071考试题库】OCP-1Z0-071最新考试题库大全-第7题

来源：优技教育

Oracle 12c的OCP考试考3科，分别是071、062、063，对于这些考题，我们专门有人负责收集整理，并由专业的老师对这些考题进行解析，希望可以帮助想考OCP的同学，这里开始介绍071的题库。

每周五晚8点，我们有免费的OCP解析公开课，地址：https://ke.qq.com/course/326223 OCP题库交流群：1015267481，验证ocp

-------------------------------------------------------

071考试题库-第7题、choose the best answer

Evaluate the following SQL statement:

ALTER TABLE hr.emp

SET UNUSED (mgr_id);

Which statement is true regarding the effect of the above SQL statement?

A) Any views created on the EMP table that include the MGR_ID column would be automatically modified and remain valid.

B) Any constraints defined on the MGR_ID column would be removed by the above command.

C) Any synonym existing on the EMP table would have to be re-created.

D) Any index created on the MGR in column would continue to exist until the DROP UNUSED COLUMNS command is executed.

Answer：B

(注意：列一旦被设置为 unused 以后，基于该列的约束、索引都被删除，同时相关的视图被无法访问。)

精华阅读