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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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
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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