Which three statements are true about views in an Oracle database?

A view is a virtual table based on a SQL query.

A. This is incorrect because a SELECT statement querying a view can contain a WHERE clause, regardless of the view’s defining query. C. This is incorrect because views can join tables from different schemas, not just the same schema. B. Correct. The rows inserted into a base table via a view remain in the table even if the view is dropped because the view is just a window to the data in the base tables. D. Correct. Views do not require storage space other than for the definition of the view in the data dictionary, hence they have no segment. E. Incorrect. Views do not have object numbers because they are not database objects that occupy physical space. F. Correct. You can create a view that references non-existent tables; such a view would be considered invalid until the base table is created.

The Oracle Database Concepts guide provides information about views and their characteristics.