本文探讨了关于数据库视图的三个正确陈述：视图可以基于表或其他视图创建；无论是简单还是复杂的视图均可利用底层表上的索引；复杂的视图能够基于存在于相同或不同模式中的多个表创建。
42.Which three statements are true regarding views? (Choose three.)
A.Views can be created only from tables.
B.Views can be created from tables or other views.
C.Only simple views can use indexes existing on the underlying tables.
D.Both simple and complex views can use indexes existing on the underlying tables.
E.Complex views can be created only on multiple tables that exist in the same schema.
F.Complex views can be created on multiple tables that exist in the same or different schemas.
答案：BDF
A：错误，可以从视图创建
B：正确
C：错误，复杂视图也可以
D：正确
E：错误，不同schema下的表，也可以创建，只要能访问就行
F：正确
A.Views can be created only from tables.
B.Views can be created from tables or other views.
C.Only simple views can use indexes existing on the underlying tables.
D.Both simple and complex views can use indexes existing on the underlying tables.
E.Complex views can be created only on multiple tables that exist in the same schema.
F.Complex views can be created on multiple tables that exist in the same or different schemas.
答案：BDF
A：错误，可以从视图创建
B：正确
C：错误，复杂视图也可以
D：正确
E：错误，不同schema下的表，也可以创建，只要能访问就行
F：正确
扫一扫
425
被折叠的 条评论
为什么被折叠?
到【灌水乐园】发言
