Ensurepass

Question 111

Consider the following relation definitions: STUDENT(

Student_Number: integer NOT NULL

Name: variable length character string length 20 ) Primary Key Student_Number

HOUSING(

Housing_ID: integer NOT NULL Student_Number: integer NOT NULL

Building: variable length character string length 25 ) Primary Key Housing_ID

Foreign Key Student_Number References STUDENT(Student_Number) ON DELETE NO ACTION

ON UPDATE CASCADE

What are the referential constraints for the relations defined in these relation definitions?

 

A. There is no relationship between changes in STUDENT(Student_Number) and HOUSING(Student_Number).

B. When STUDENT(Student_Number) is changed or deleted, this modification or deletion will automatically be reflected in

HOUSING(Student_Number).

C. Modifications to HOUSING(Student_Number) are automatically reflected in changes to STUDENT(Student_Number), but deletions are not

permitted.

D. Modifications to STUDENT(Student_Number) are automatically reflected in changes to HOUSING(Student_Number). For a deletion to occur

from STUDENT(Student_Number), it must first occur in HOUSING(Student_Number).

 

Answer: D

 

 

Question 112

Consider the following relation definition: STUDENT(

Student_Number: integer NOT NULL

Name: variable length character string length 20 NOT NULL) Primary Key Student_Number

HOUSING(

Housing_ID: integer NOT NULL Student_Number: integer NOT NULL

Building: variable length character string length 25 NOT NULL) Primary Key Housing_ID

Foreign Key Student_Number References STUDENT(Student_Number)

ON DELETE NO CHECK ON UPDATE

Which integrity constraint is violated in this relation definition?

 

A. Entity integrity

B. Domain constraint

C. Referential integrity

D. Enterprise constraint

 

Answer: C

 

 

Question 113

Which characteristic is an advantage of a database management system?

 

A. Data files are owned and maintained by the users.

B. Database administration is simplified.

C. A standard method can be used to access the database.

D. Data is decentralized.

 

Answer: C

 

 

Question 114

Which of the following best describes a composite key?

 

A. A composite key is a primary key and foreign key that consists of the first two attributes of a relation.

B. A composite key is a primary or foreign key defined by its parent key attributes.

C. A composite key is a foreign key that consists of the same attributes as the primary key from a related table.

D. A composite key is a primary or foreign key that consists of two or more attributes of a relation.

 

Answer: D

 

 

Question 115

Consider the Project relation shown in the exhibit as well as the following SQL statement:

DELETE FROM Project WHERE Cust_Name = Acme;

Which of the following tables shows the Project relation after execution of this SQL statement?

clip_image002

 

A. clip_image004

B. clip_image006

C. clip_image008

D. clip_image010clip_image012

 

Answer: A

 

 

Question 116

Consider the Stu_Act and Act_Fee tables shown in the exhibit. Which relational algebraic operation would yield the Activity Relation table in the exhibit?

 

A. Union

B. Intersection

C. Natural join

D. Cartesian product

 

Answer: C

 

 

Question 117

A relation for a construction company is shown in the exhibit. Which of the following best defines the relationship between Cust_ID and Cust_Name?

clip_image014

A. Cust_Name is the determinant.

B. Cust_Name is transitively dependent on Cust_ID.

C. Cust_ID is transitively dependent on Cust_Name.

D. Cust_Name is functionally dependent on Cust_ID.

 

Answer: D

 

 

Question 118

A large enterprise uses a two-tier database architecture and runs complex database processing on the client. Which term best describes the client in this system?

 

A. Fat client

B. Thin client

C. Terminal client

D. Enterprise client

 

Answer: A

 

 

Question 119

Consider the table shown in the exhibit. Which relational algebraic operation would return Row 3?

clip_image016

A. Union

B. Selection

C. Projection

D. Difference

 

Answer: B

 

 

Question 120

Which of the following best describes the ON DELETE NO ACTION referential integrity constraint?

 

A. If a parent key is deleted, any child keys referenced by the parent key are automatically deleted.

B. If a parent key is deleted, no test is made for referential integrity.

C. If any child key references a parent key, the record containing the parent key cannot be deleted.

D. If a parent key is deleted, all child keys are automatically set to a specified value.

 

Answer: C

 

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