CS403 Midterm Online Quiz

2 votes, 5 avg

CS403-Midterm

1 / 50

Identify the correct statement.

Referential integrity constraints are specified between entities having recursive relationships.

Referential integrity constraints check whether an attribute value lies in the given range.

Referential integrity constraints check whether the primary key values are unique.

When Referential integrity rules are enforced, a tuple in one relation that refers to another relation must refer to an existing tuple.

2 / 50

Which of the following is true about relational schema?

Contains only derived attributes.

Values are atomic.

The sequence of rows is significant.

The sequence of columns is significant

3 / 50

The ER- data model is an example of:

Conceptual database

Physical database

Relational database

Logical database

4 / 50

Which of the following is not a benefit of normalization?

Minimize updation anomolies

Minimize insertion anomolies

Maximize redundancy

Minimize deletion anomolies

5 / 50

Which of the following constraints enforces entity integrity?

PRIMARY KEY

NOT NULL

CHECK

FOREIGN KEY

6 / 50

Consider the following statements.
A. Conceptual schema which is the result of conceptual design is a logical description of all data elements and their relationships.
B. Internal level of the database architecture consists of the physical view of the database.
C. External level of the database architecture provides the user view of the database.
With respect to the ANSI/SPARC three level database architecture, which of the above is/are correct?

Only A.

Only B and C.

Only C.

Only A and B.

7 / 50

Identify the correct statement.

Entity integrity constraints are specified on individual relations.

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

Entity integrity constraints specify that primary key values can be composite.

Entity integrity constraints are specified between weak entities.

8 / 50

Which of the following is NOT a feature of Context DFD?

sub-processes (which explain and decomposed the major process into small processes)

data flows linking the process to the sources and sinks (external entities)

one process (which represents the entire system)

all sources/sinks (external entities)

9 / 50

Identify the correct statement with respect to normalization.

The process of normalization through decomposition must achieve the dependency reservation property at any cost whereas the lossless join property is sometimes sacrificed.

The process of normalization through decomposition must achieve the lossless join property at any cost whereas the dependency reservation property is sometimes sacrificed.

Normalization can be used as a top-down standalone database design technique.

Normalization is a formal technique that can be used only at the starting phase of the database design.

10 / 50

Which of the following functions are NOT performed by a database administrator?

Establishing standards and procedures for database systems

Allocation of storage locations and data structures

Communicating with database users

Planning, designing and implementing database systems

11 / 50

Controlling redundancy in a database management system DOES NOT help to

avoid unauthorised access to data

avoid inconsistency among data

avoid duplication

avoid unnecessary wastage of storage space

12 / 50

A software package designed to store and manage databases

Data model

DBMS

Data

Database

13 / 50

Which of the following enforces a relation into 1st normal form?

The domain of attribute must include only atomic values.

Every non-key attribute is partially dependent on super key

Every non-key attribute is fully functionally dependent on primary key

non-key attribute is non-transitively dependent on primary key.

14 / 50

Which of the following is not true about relational tables?

The sequence of rows is significant.

Each column must have a unique name.

Column values are of the same kind.

Each row is unique.

15 / 50

Which of the following most certainly implies the need for an entire table to implement?

A ternary relationship

A recursive relationship

A binary relationship

An identifying relationship

16 / 50

Consider the relation Interview (CandidateNo, InterviewDate, InterviewTime, StaffNo, RoomNo) and the following functional dependencies.
FD1 : CandidateNo, InterviewDate -> InterviewTime, StaffNo, RoomNo
FD2 : RoomNo, InterviewDate, InterviewTime -> StaffNo, CandidateNo
FD3 : StaffNo, InterviewDate -> RoomNo
Which of the following is correct?

The relation Interview is in 3NF

The relation Interview is in BCNF.

The FD3 violates 3NF.

The FD2 violates 2NF.

17 / 50

The ____ constraint specifies whether each entity supertype occurrence must also be a member of at least one subtype.

uniqueness

specialization

inheritance

completeness

18 / 50

Who is responsible for authorizing access to the database, for coordinating and monitoring its use?

Application Programmer

Database Designer

Database Administrator

End User

19 / 50

Which of the following is true about NOT NULL constraint?

prevents any actions that would destroy links between tables with the corresponding data values

enforces the uniqueness of the values in a set of columns

limit the values that can be placed in a column

enforce domain integrity

20 / 50

Which of the following is correct?

The relation Interview is in 3NF

The FD3 violates 3NF.

The relation Interview is in BCNF.

The FD2 violates 2NF.

21 / 50

Select the correct statement among the following.

Partial participation which is also called existence dependency is displayed as a double line connecting the participating entity type to the relationship.

Cardinality ratios for binary relationship are displayed on Entity Relationship Diagrams by using a diamond shape notation

When different entity types participate only once in a single relationship type it is called a recursive relationship

Role names are not technically necessary in relationship types when all the participating entity types are distinct.

22 / 50

User rights information is stored in

Logical database

Buffer

Catalog

Physical database

23 / 50

Which of the following is true about relational schema?

The sequence of columns is significant

Values are atomic.

The sequence of rows is significant.

Contains only derived attributes.

24 / 50

The ER- data model is an example of:

Relational database

Conceptual database

Logical database

Physical database

25 / 50

A collection of concepts that can be used to describe the structure of a database

Data model

Data

Database

DBMS

26 / 50

Which of the following statements is NOT correct?

The functional dependency (EmpNo, DeptNo) -> ProjNo holds over R.

The functional dependency EmpNo -> DeptNo holds over R.

The functional dependency (EmpNo, ProjNo) -> DeptNo holds over R.

The functional dependency ProjNo -> DeptNo holds over R.

27 / 50

The ____ constraint specifies whether each entity supertype occurrence must also be a member of at least one subtype.

completeness

inheritance

specialization

uniqueness

28 / 50

Identify the correct way to implement one-to-one relationship in tables?

by creating two separate tables

using a junction table with the keys from both the tables forming the composite primary key of the junction table.

as a single table and rarely as two tables with primary and foreign key relationships.

by splitting the data into two tables with primary key and foreign key relationships.·

29 / 50

A collection of concepts that can be used to describe the structure of a database

Data model

Data

DBMS

Database

30 / 50

Structural constraints of a relationship type refer to

the role that a participating entity from the entity type plays in each relationship instance.

identifying the owner entity type relevant to a given entity type

the constraints applicable in granting access to tables, columns and views in a database schema.

whether the existence of an entity depends on it being related to another entity via the relationship type.

31 / 50

Identify the INCORRECT statement among the given

One cannot consider something which has conceptual existence like a course in a degree program as an entity.

Age can be considered as a single value attribute of a person.

An entity type describes the schema or intension for a set of entities which share the same structure.

An entity may be an object with a physical existence like a car, a house or an Employee.

32 / 50

Which of the following constraints enforces entity integrity?

CHECK

FOREIGN KEY

NOT NULL

PRIMARY KEY

33 / 50

Structural constraints of a relationship type refer to

the constraints applicable in granting access to tables, columns and views in a database schema.

identifying the owner entity type relevant to a given entity type

whether the existence of an entity depends on it being related to another entity via the relationship type.

the role that a participating entity from the entity type plays in each relationship instance.

34 / 50

Which of the following is true for the relational model?

Nullvalue is a blank or zero value given to an attribute value when its value is inapplicable or its value is unknown.

Complex key is a key consisting of more than one attribute.

Constraint is a rule that restricts the values in a database.

Degree of a relation is the number of rows in a relation.

35 / 50

Which of the following is NOT a feature of Context DFD?

one process (which represents the entire system)

data flows linking the process to the sources and sinks (external entities)

► sub-processes (which explain and decomposed the major process into small processes)

all sources/sinks (external entities)

36 / 50

Identify the correct statement.

Entity integrity constraints specify that primary key values can be composite.

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

Entity integrity constraints are specified between weak entities.

Entity integrity constraints are specified on individual relations.

37 / 50

A database system allows the following EXCEPT

management and control of data towards an efficient working of an organisation.

more critical functions in organisations to be computerised and the need to keep a large volume of data available in an up to the minute current state increased.

any user to access all its data.

integration of data across multiple applications into a single application

38 / 50

A collection of related data is

Logical model

Database

Data

Relational model

39 / 50

User rights information is stored in

Physical database

Logical database

Buffer

Catalog

40 / 50

Consider the following statements.
A. An entity integrity constraint states that no primary key value can be null.
B. A referential integrity constraint is specified between two relations.
C. A foreign key cannot be used to refer to its own relation.
Identify which of the above statements is/are correct.

Only B

B and C

Only A

A and B

41 / 50

Which of the following is a feature of PRIMARY KEY constraint?

allow any actions that would destroy links between tables

limit the values that can be placed in a column.

enforces that the column will only accept null values.

unique identifier for a row within a database table.

42 / 50

Identify the constraint that limits the values that can be placed in a column.

FOREIGN KEY

UNIQUE

CHECK

NOT NULL

43 / 50

Which relational algebra operation could have been applied on the pair of relations Student and Instructor to obtain the above data?

Instructor ÷ Student

Student ∩ Instructor

Instructor – Student

Student – Instructor

44 / 50

A relation (from the relational database model) consists of a set of tuples, which implies that

relational model supports multi-valued attributes whose values can be represented in sets.

all tuples in a particular relation may have different attributes.

for any two tuples, the values associated with all ofheirt attributes may be the same.

all tuples in a relation must be distinct.

45 / 50

B and C

Only B

A and B

Only A

46 / 50

Which of the following constraints enforces entity integrity?

FOREIGN KEY

NOT NULL

PRIMARY KEY

CHECK

47 / 50

Which of the following is INCORRECT statement concerning the database design process?

By referring to a high level data model, it is possible to understand the data requirements of the users, entity types, relationships and constraints

During requirements collection and analysis phase, one can gather the data requirements of database users.

During the logical design phase of internal storage structures, access paths and file organization for the database files are specified

Transformation of the high level data model into the implementation data model is called logical design or data model mapping

48 / 50

Which of the following is a correct way to implement one-to-many relationship while designing tables?

using a junction table with the keys from both the tables forming the composite primary key of the junction table.

by splitting the data into two tables with primary key and foreign key relationships.

as a single table and rarely as two tables with primary and foreign key relationships.

by splitting each table into three

49 / 50

Which of the following is a correct way to implement one-to-many relationship while designing tables?

by splitting each table into three

as a single table and rarely as two tables with primary and foreign key relationships

using a junction table with the keys from both the tables forming the composite primary key of the junction table.

by splitting the data into two tables with primary key and foreign key relationships

50 / 50

Database management systems, operating systems, applications and utilities are all examples of ____.

software

hardware

computer infrastructure

input and output

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