Oracle Database Administration I — Question 99

Which three statements are true about performing Data Manipulation Language (DML) operations on a view with no INSTEAD OF triggers defined? (Choose three.)

Answer options

• A. Views cannot be used to query rows from an underlying table if the table has a PRIMARY KEY and the PRIMARY KEY columns are not referenced in the defining query of the view.
• B. The WITH CHECK clause has no effect when deleting rows from the underlying table through the view.
• C. Delete statements can always be done on a table through a view.
• D. Views cannot be used to add or modify rows in an underlying table if the defining query of the view contains the DISTINCT keyword.
• E. Views cannot be used to add rows to an underlying table if the table has columns with NOT NULL constraints lacking default values which are not referenced in the defining query of the view.
• F. Insert statements can always be done on a table through a view.

Correct answer: C, E, F

Explanation

The correct answers are C, E, and F because delete operations may not always be permitted through a view, particularly when there are constraints that are not satisfied as specified in E. Inserting is limited by constraints, which is why E is also correct. Statement F is accurate as it indicates that insert operations can generally be conducted through a view if no restrictions apply. The incorrect options A, B, and D misrepresent how views interact with primary keys, deletion checks, and the DISTINCT keyword, respectively.