Oracle Database 12c: SQL Fundamentals — Question 19

Which two statements are true regarding views? (Choose two.)

Answer options

• A. A sub query that defines a view cannot include the GROUP BY clause
• B. A view is created with the sub query having the DISTINCT keyword can be updated
• C. A Data Manipulation Language (DML) operation can be performed on a view that is created with the sub query having all the NOT NULL columns of a table
• D. A view that is created with the sub query having the pseudo column ROWNUM keyword cannot be updated

Correct answer: C, D

Explanation

Option C is correct because a view that includes all NOT NULL columns from the base table allows DML operations to be performed. Option D is also correct since views created with the ROWNUM pseudo column are not updatable due to the nature of how ROWNUM functions. Options A and B are incorrect as they misrepresent the capabilities and limitations of views in SQL.