SOLOSOLOKU: Section 16 Quiz

Test: Section 16 Quiz
Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer.

Section 16 Quiz
(Answer all questions in this section)

1. Which of the following best describes the function of an index?

An index can run statement blocks when DML actions occur against a table.
An index can reduce the time required to grant multiple privileges to users.
An index can prevent users from viewing certain data in a table.
An index can increase the performance of SQL queries that search large tables. (*)

2. Unique indexes are automatically created on columns that have which two types of constraints?
UNIQUE and FOREIGN KEY
PRIMARY KEY and FOREIGN KEY
UNIQUE and PRIMARY KEY (*)
NOT NULL and UNIQUE

3. Which of the following is created automatically by Oracle when a UNIQUE integrity constraint is created?  
A PRIMARY KEY constraint
A FOREIGN KEY constraint
An index (*)
A CHECK constraint

4. Indexes can be used to speed up queries. True or False?
True (*)
False

5. Which one of the following statements about indexes is true?  
An index is created automatically when a PRIMARY KEY constraint is created. (*)
An index must be created by a database administrator when a PRIMARY KEY constraint is created.
An index cannot be created before a PRIMARY KEY constraint is created.
An index is never created for a unique constraint.

Test: Section 16 Quiz
Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer.

Section 16 Quiz
(Answer all questions in this section)

6. User Mary's schema contains an EMP table. Mary has Database Administrator privileges and executes the following statement:
CREATE PUBLIC SYNONYM emp FOR mary.emp;

User Susan now needs to SELECT from Mary's EMP table. Which of the following SQL statements can she use?

(Choose two)
(Choose all correct answers)

SELECT * FROM emp; (*)
SELECT * FROM emp.mary;
CREATE SYNONYM marys_emp FOR mary(emp);
SELECT * FROM mary.emp; (*)

7. The EMPLOYEES table contains these columns:
EMP_ID NOT NULL, Primary Key
SSNUM NOT NULL, Unique
LAST_NAME VARCHAR2(25)
FIRST_NAME VARCHAR2(25)
DEPT_ID NUMBER Foreign Key to DEPT_ID column of the DEPARTMENTS table
SALARY NUMBER(8,2)
You execute this statement:

CREATE INDEX emp_name_idx
ON employees(last_name, first_name);

Which statement is true?

The statement creates a function-based index.
The statement fails because of a syntax error.
The statement creates a composite unique index.
The statement creates a composite non-unique index. (*)

8. In order to be able to generate primary key values that are not likely to contain gaps, which phrase should be included in the sequence creation statement?
CACHE
MAXVALUE
NOCACHE (*)

9. Evaluate this CREATE SEQUENCE statement:
CREATE SEQUENCE order_id_seq NOCYCLE NOCACHE; Which statement is true?

The sequence has no maximum value.
The sequence will start with 1. (*)
The sequence preallocates values and retains them in memory.
The sequence will continue to generate values after reaching its maximum value.

10. To see the most recent value that you fetched from a sequence named my_seq you should reference:

my_seq.(lastval)
my_seq.currval (*)
my_seq.nextval
my_seq.(currval)

Incorrect Incorrect. Refer to Section 16 Lesson 1.

Test: Section 16 Quiz
Review your answers, feedback, and question scores below. An asterisk (*) indicates a correct answer.

Section 16 Quiz
(Answer all questions in this section)

11. Evaluate this statement:
SELECT po_itemid_seq.CURRVAL
FROM dual; What does this statement accomplish?

It displays the next available value of the PO_ITEM_ID_SEQ sequence.
It displays the current value of the PO_ITEM_ID_SEQ sequence. (*)
It resets the current value of the PO_ITEM_ID_SEQ sequence.
It sets the current value of the PO_ITEM_ID_SEQ sequence to the value of the PO_ITEMID column.

12. Why do gaps in sequences occur?  

A rollback is executed
The system crashes
The sequence is used in another table
All of the above (*)

13. A sequence is a database object. True or False?

True (*)
False

14. Evaluate this statement:
CREATE SEQUENCE line_item_id_seq
MINVALUE 100 MAXVALUE 130 INCREMENT BY -10 CYCLE;
What will be the first five numbers generated by this sequence?

130120110100130
The CREATE SEQUENCE statement will fail because a START WITH value was not specified. (*)
The fifth number cannot be generated.
100110120130100

15. Examine the code for creating this sequence:
CREATE SEQUENCE track_id_seq
INCREMENT BY 10
START WITH 1000 MAXVALUE 10000
What are the first three values that would be generated by the sequence?


0, 1, 2
1100, 1200, 1300
1000, 1010, 1020 (*)
100010011002