tailieunhanh - OCA: Oracle Database 11g Administrator Certified Associate Study Guide- P10

OCA: Oracle Database 11g Administrator Certified Associate Study Guide- P10: There is high demand for professionals in the information technology (IT) industry, and Oracle certifications are the hottest credential in the database world. You have made the right decision to pursue certification, because being Oracle Database 11g certified will give you a distinct advantage in this highly competitive market. | Review Questions 381 5. You create a view based on the EMPLOYEES table using the following SQL. CREATE VIEW MYVIEW AS SELECT FROM EMPLOYEES You modify the table to add a column named EMP_SSN. What do you need to do to have this new column appear in the view A. Nothing. Since the view definition is selecting all columns the new column will appear in the view automatically. B. Recompile the view using ALTER VIEW MYVIEW RECOMPILE. C. Re-create the view using CREATE OR REPLACE VIEW. D. Add the column to the view using ALTER VIEW MYVIEW ADD EMP_SSN. 6. Which is a valid status of a constraint created on a view A. DISABLE VALIDATE B. DISABLE NOVALIDATE C. ENABLE NOVALIDATE D. All of the above 7. The SALARY column of the EMPLOYEE table is defined as NUMBER 8 2 and the COMMIS-SION_PCT column is defined as NUMBER 2 2 . A view is created with the following code CREATE VIEW EMP_COMM AS SELECT LAST_NAME SALARY NVL COMMISSION_PCT 0 Commission FROM EMPLOYEES What is the datatype of the COMMISSION column in the view A. NUMBER 8 2 B. NUMBER 10 2 C. NUMBER D. FLOAT 8. Which clause in the SELECT statement is not supported in a view definition subquery A. GROUP BY B. HAVING C. CUBE D. FOR UPDATE OF E. ORDER BY 382 Chapter 7 Creating Schema Objects 9. The EMPLOYEE table has the following columns EMP_ID NUMBER 4 EMP_NAME VARCHAR2 30 SALARY NUMBER 6 2 DEPT_ID VARCHAR2 2 Which query will show the top five highest-paid employees A. SELECT FROM SELECT EMP_NAME SALARY FROM EMPLOYEE ORDER BY SALARY ASC WHERE ROWNUM 5 B. SELECT EMP_NAME SALARY FROM SELECT FROM EMPLOYEE ORDER BY SALARY DESC WHERE ROWNUM 5 C. SELECT FROM SELECT EMP_NAME SALARY FROM EMPLOYEE ORDER BY SALARY DESC WHERE ROWNUM 5 D. SELECT EMP_NAME SALARY SELECT FROM EMPLOYEE ORDER BY SALARY DESC WHERE ROWNUM 5 Review Questions 383 10. The EMPLOYEE table has the following columns EMP_ID NUMBER 4 PRIMARY KEY EMP_NAME VARCHAR2 30 SALARY NUMBER 6 2 DEPT_ID VARCHAR2 2 A view is defined using the following SQL CREATE VIEW EMP_IN_DEPT10 .