Assignment

1. Assume you are using the INTERSECT operator to combine the results from two tables with identical structure, CUSTOMER and CUSTOMER_2. The CUSTOMER table contains 10 rows, while the CUSTOMER_2 table contains 7 rows. Customers Dunne and Olowski are included in the CUSTOMER table as well as in the CUSTOMER_2 table. How many records are returned when using the INTERSECT operator?

a. 0 b. 2

c. 7 d. 10

ANSWER:

2. The statement in SQL combines rows from two queries and returns only the rows that

appear in the first set but not in the second.

a. UNION b. UNION ALL

c. INTERSECT d. MINUS

ANSWER:

3. Assume you are using the MINUS operator to combine the results from two tables with identical structure, CUSTOMER and CUSTOMER 2. The CUSTOMER table contains 10 rows, while the CUSTOMER 2 table contains 7 rows. Customers Dunne and Olowski are included in the CUSTOMER table as well as in the CUSTOMER 2 table. How many records are returned when using the MINUS operator?

a. 0 b. 2

c. 8 d. 10

ANSWER:

1. A derives its name from the fact that a collection of multiple entries of the same type can

exist for any single key attribute occurrence.

( a. partial dependency c. repeating group ) ( transitive dependency d. primary key )ANSWER:

2. A relational table must not contain a(n) .

a. entity b. attribute

c. relationship d. repeating group

ANSWER:

3. Dependencies based on only a part of a composite primary key are known as dependencies.

a. primary b. partial

c. incomplete d. composite

ANSWER:

1. The command would be used to delete the table row where the P_CODE is ‘BRT-345 ’.

a. DELETE FROM PRODUCT

WHERE P CODE = ‘BRT-345’;

b. REMOVE FROM

PRODUCT WHERE P_CODE = ‘BRT- 345’;

c. ERASE FROM PRODUCT

WHERE P_CODE = ‘BRT-345’;

d. ROLLBACK FROM

PRODUCT WHERE P_CODE = ‘BRT-

345’;

ANSWER:

2. A(n) is a query that is embedded (or nested) inside another query.

a. alias b. operator

c. subquery d. view

ANSWER:

3. Which of the following queries will output the table contents when the value of V CODE is equal to 21344?

a. SELECT PDESCRIPT, PINDATE, P_PRICE,

· CODE FROM PRODUCT WHERE V CODE o 21344;

b. SELECT P DESCRIPT, P INDATE, P_PRICE,

· CODE FROM PRODUCT WHERE V CODE <= 21344;

c. SELECT P DESCRIPT, P INDATE, P_PRICE,

· CODE FROM PRODUCT WHERE V CODE = 21344;

d. SELECT P DESCRIPT, P INDATE, P_PRICE,

· CODE FROM PRODUCT WHERE V CODE => 21344;

ANSWER:

1. data refer to data whose values change over time and for which one must keep a history of

the data changes.

a. Time-sensitive b. Time-variant

c. Historical d. Change-based

ANSWER:

2. A occurs when there is one entity in two 1:M relationships to other entities, thus producing

an association among the other entities that is not expressed in the model.

a. surrogate primary key b. time-variant data c. design trap d. fan trap

ANSWER:

3. relationships occur when there are multiple relationship paths between related entities.

a. Redundant b. Duplicated c. Time-variant d. Supertype

ANSWER:

1. The Crow’s foot symbol with two vertical parallel lines indicates cardinality.

a. (0,N) b. (1,N) c.(l,l) d. (0,1)

2. A relationship exists when an association is maintained within a single entity.

3. A relationship exists when three entities are associated.

a. unary b. strong

c. ternary d. weak

ANSWER:

4. What is a weak relationship? Provide an example.

ANSWER:

1. Explain the two criteria that help a designer in determining when to use subtypes and super types. ANSWER:

( ANSWER: )

4. Explain the Boyce-Codd normal form (BCNF). How is it related to other normal forms?

( ANSWER: ) ( 4. Explain the two SQL functions. ANSWER: 1. ) ( 2 . ) ( 4. Describe the characteristics of an Oracle sequence. ) ( ANSWER: - )

Question 21: There are two communications service (Voice, data, and image) providers (Carriers); Named,

1- TMOBIL 1(packet Switch Network based) &

2- TMOBIL 2 (Circuit Switch Network based):

Answer:

* What is the main differences between Packet Switch Network & Circuit Switch Network?

** Which one do you select and why?

Questing 22: Provide your own opinions and some discussion points abut "time variant" and "time invariant" OF Data Base systems

( INPUT )