Software Architecture

Question 1

 

select the correct statement from the following on referential integrity

Select one:

a. referential integrity constraints check whether the primary key, values are unique

b. referential integrity constraints check whether an attribute values lies in the given range

c. referential integrity constraints are specified between two relations in a schema

d. referential integrity constraints are specified between entities having recursive relationship

Feedback

 .

The correct answer is: referential integrity constraints are specified between two relations in a schema

 

Question 2

In airline reservation system, the entities are date, flight number,place of departure destination, type of plane and seats available.The primary Key is

Select one:

a. Flight number + date

b. flight number+ place of departure

c. flight number + destination

d. flight number

Feedback

 .

The correct answer is: Flight number + date

Question 3

 Choose the incorrect statements

1) In network model, data is represented by a collection of records, and relationship among data are represented by links

2) In hierarchical model, data and relationship among data are represented by records and links respectively

3) In hierarchical model, the records are organized as a collection of arbitrary graphs.

4) in network model, the records are organized as a collection of trees.

Select one:

a. 1 and 3 only

b. 3 and 4 only

c. All are correct

d. 2 and 3 only

Feedback

 .

The correct answer is: 3 and 4 only

Question 4

 

Let R(a,b,c) and S(d,e,f) be two relations in which d is the foreign key of S that refers to the primary key of R. consider the following four operations R and S.

1. Insert into R

2. Insert into S

3. Delete from R

4. Delete from S.

which of the following is true about the referential integrity constraints above?

Select one:

a. Both 2 and 3 can cause its violation

b. Both 1 and 4 can cause its violation

c. All of 1,2,3 and 4 can cause its violation

d. None of 1,2,3 or 4 can cause its violation

Feedback

 .

The correct answer is: Both 2 and 3 can cause its violation

Question 5

 

Which of the following statement is false

Select one:

a. primary key cannot have NULL value

b. every candidate key is a super key

c. a foreign key is necessarily the primary key in referenced relation

d. every relation has at least one super key

Feedback

 .

The correct answer is: a foreign key is necessarily the primary key in referenced relation

Question 6

 

The column of a table is referred to as the

Select one:

a. Attribute

b. Entity

c. Degree

d. Tuple

Feedback

 .

The correct answer is: Attribute

Question 7

Student and courses enrolled is an example of

Select one:

a. many -to- one relationship

b. Many-to -many relationship

c. one-to-many relationship

d. one-to-one relationship

Feedback

Your answer is incorrect.

The correct answer is: Many-to -many relationship

Question 8

 

Consider the entities "hotel room" and "person" with a many to many relationship "loading". if we wish to store information about the rent payment to be made by person(s) occupying different hotel rooms, then this information should appear as an attribute of

Select one:

a. person

b. none of the above

c. Hotel room

d. lodging

Feedback

 .

The correct answer is: lodging

Question 9

 

Entity set TRANSACTION has the attributes transaction number, date, amount. Entity set Account has the attributes account number, customer  name, balance.

which is the discriminator of the weak entity?

Select one:

a. Transaction number

b. Account number

c. {account number, date}

d. date

Feedback

 .

The correct answer is: Transaction number

Question 10

 

In an E-R diagram ellipses represent

Select one:

a. Entity sets

b. link between attributes and entity sets

c. Attributes

d. Relationship among entity sets

Feedback

 .

The correct answer is: Attributes

Question 11

 

The set of permitted values for each attribute is called its

Select one:

a. Attribute set

b. Domain

c. Group

d. Attribute range

Feedback

 .

The correct answer is: Domain

Question 12

 

A primary key if combined with a foreign key creates

Select one:

a. parents child relationship between the tables that connect them

b. network model between the tables that connect them

c. none of the above

d. many-to-many relationship between the table that connect them

Feedback

 .

The correct answer is: parents child relationship between the tables that connect them

Question 13

 

Which of the following statements is correct with respect to entity integrity?

Select one:

a. when entity integrity rules are enforced a tuple in one relation that refers to another relation must refer to an existing tuple

b. entity integrity constraints are specified between weak entities

c. entity integrity constraints are specified on individual relations d. Entity integrity constraints specify that primary key values can be composite

Feedback

 .

The correct answer is: entity integrity constraints are specified on individual relations

Question 14

 

A trigger is

Select one:

a. a statement that is executed by the user when debugging an application program

b. a statement that is executed automatically by the system as a side effect of a modification to the database

c. a condition the system tests for the validity of the database user

d. a statement that enables to start any DBMS

Feedback

 .

The correct answer is: a statement that is executed automatically by the system as a side effect of a modification to the database

Question 15

 

Which of the following is NOT an advantage of the database approach?

Select one:

a. All of the above are advantages

b. Ability to associate related data

c. Elimination of the data redundancy

d. Increased Security

Feedback

 .

The correct answer is: All of the above are advantages

Question 16

 

An attribute of the table matching the primary key of another table, is called as

Select one:

a. Foreign key

b. Secondary Key

c. Composite key

d. Candidate Key

Feedback

 .

The correct answer is: Foreign key

Question 17

 

Which of the following is NOT an advantage of DBMS?

Select one:

a. it provides access control

b. it ensures atomicity of transactions

c. it maintains data is non-redundant fashion

d. designing database is a complex task

Feedback

 .

The correct answer is: designing database is a complex task

Question 18

 

Which of the following statement concerning relational database is true?

Select one:

a. the primary key fields of a relation must be adjacent

b. all the relations must be in at least third normal form

c. a primary key field may be null

d. A foreign key field may be null Feedback

 .

The correct answer is: A foreign key field may be null

Question 19

 

E-R modeling techniques is a

Select one:

a. Bottom-up approach

b. Top-Down approach

c. Left-right approach

d. Both top-down and bottom-up

Feedback

 .

The correct answer is: Top-Down approach

Question 20

 

The employee salary should not be greater than rs 2500 this is

Select one:

a. Integrity constraint

b. over-defined constraint

c. Referential constraint

d. feasible constraint

Feedback

 .

The correct answer is: Integrity constraint

Question 21

 

Manager's salary details are hidden from the employee. this is

Select one:

a. Physical level data hiding

b. Conceptual level data hiding

c. external level data hiding

d. None of the above

Feedback

 .

The correct answer is: external level data hiding

Question 22

 

A specific example where physical data independence would not hold is ____

Select one:

a. when an additional access structure, (example, an index) is created for a relation

b. when the user writes an application program to join tables

c. When DBA decides to store the data in a B+ tree

d. when data file is changed from an un-ordered file to a sorted file

Feedback

 .

The correct answer is: when the user writes an application program to join tables

Question 23

 

A data model is a collection of conceptual tools for describing

Select one:

a. None of the above

b. Data semantics and consistency constraints

c. Data and Data relationships

d. Data, data relationship, data semantics and consistency constraints

Feedback

 .

The correct answer is: Data, data relationship, data semantics and consistency constraints

Question 24

 

Generally speaking, for a weak entity set to be meaningful it must be part of a

Select one:

a. Many-to-many relationship

b. One-to-one relationship

c. None of the above

d. One-to-many relationship

Feedback

 .

The correct answer is: One-to-many relationship

Question 25

 

The Database administrator is, in effect, the coordinator between the ___________ and the _____________

Select one:

a. Database; Users

b. Application program; Database

c. Application programs; Users

d. DBMS; Database

 

The correct answer is: DBMS; Database