CS403 Midterm Online Quiz

2 votes, 5 avg

CS403-Midterm

1 / 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.

B and C

Only A

Only B

A and B

2 / 50

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

Allocation of storage locations and data structures

Planning, designing and implementing database systems

Establishing standards and procedures for database systems

Communicating with database users

3 / 50

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

uniqueness

specialization

completeness

inheritance

4 / 50

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

Student – Instructor

Instructor ÷ Student

Instructor – Student

Student ∩ Instructor

5 / 50

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

Application Programmer

Database Designer

End User

Database Administrator

6 / 50

Which of the following statements is NOT correct?

The functional dependency EmpNo -> DeptNo holds over R.

The functional dependency DeptNo -> ProjNo holds over R.

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

The functional dependency ProjNo -> DeptNo holds over R.

7 / 50

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

weak

unary

binary

ternary

8 / 50

Identify the correct statement.

Entity integrity constraints are specified between weak entities.

Entity integrity constraints are specified on individual relations.

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.

9 / 50

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

unique identifier for a row within a database table.

enforces that the column will only accept null values.

allow any actions that would destroy links between tables

limit the values that can be placed in a column.

10 / 50

Which of the following is true about relational schema?

The sequence of rows is significant.

Contains only derived attributes.

The sequence of columns is significant

Values are atomic.

11 / 50

Which of the following is true about NOT NULL constraint?

limit the values that can be placed in a column

enforce domain integrity

enforces the uniqueness of the values in a set of columns

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

12 / 50

Which of the following is true for the relational model?

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

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

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

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

13 / 50

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

DBMS

Data model

Data

Database

14 / 50

Identify the INCORRECT statement among the given

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

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

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

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

15 / 50

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

hardware

software

computer infrastructure

input and output

16 / 50

Which of the following is correct?

The FD3 violates 3NF.

The relation Interview is in BCNF.

The FD2 violates 2NF.

The relation Interview is in 3NF

17 / 50

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

inheritance

completeness

specialization

uniqueness

18 / 50

User rights information is stored in

Buffer

Logical database

Physical database

Catalog

19 / 50

statement among the following on the above diagram.

The participation of Z in the Y relationship type is partial.

The diagram depicts existence dependencies.

The participation of X in the Y relationship type is total.

The relationship type Y is of cardinality ratio 1 : N.

20 / 50

In a conceptual model for a university, what type of relationship exists between Grade and Student entities?

M:M

1:M

Ternary

1:01

21 / 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 BCNF.

The relation Interview is in 3NF

The FD2 violates 2NF.

The FD3 violates 3NF.

22 / 50

A database system allows the following EXCEPT

integration of data across multiple applications into a single application

any user to access all its data.

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.

23 / 50

Controlling redundancy in a database management system DOES NOT help to

avoid inconsistency among data

avoid duplication

avoid unauthorised access to data

avoid unnecessary wastage of storage space

24 / 50

Which of the following is not a benefit of normalization?

Minimize insertion anomolies

Minimize deletion anomolies

Minimize updation anomolies

Maximize redundancy

25 / 50

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

CHECK

NOT NULL

UNIQUE

FOREIGN KEY

26 / 50

The ER- data model is an example of:

Logical database

Conceptual database

Physical database

Relational database

27 / 50

Which of the following is not true about relational tables?

Column values are of the same kind.

Each row is unique.

Each column must have a unique name.

The sequence of rows is significant.

28 / 50

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

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

one process (which represents the entire system)

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

all sources/sinks (external entities)

29 / 50

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

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.·

by creating two separate tables

30 / 50

Select the correct statement about the ANSI/SPARC architecture.

The conceptual level is a level of indication between the internal level and the external level.

The internal level in a database system will definitely be relational.

Any given database has many conceptual schemas and one physical schema, but it has only one external schemas.

The external level is not concerned with individual user perceptions, while the conceptual level is concerned with a community user perception.

31 / 50

Which of the following constraints enforces entity integrity?

PRIMARY KEY

NOT NULL

FOREIGN KEY

CHECK

32 / 50

Which of the following constraints enforces entity integrity?

CHECK

FOREIGN KEY

PRIMARY KEY

NOT NULL

33 / 50

Structural constraints of a relationship type refer to

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.

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

34 / 50

Select the correct statement among the following.

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

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

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

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

35 / 50

A software package designed to store and manage databases

Data

Data model

DBMS

Database

36 / 50

The ER- data model is an example of:

Relational database

Logical database

Physical database

Conceptual database

37 / 50

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

Data

Database

Data model

DBMS

38 / 50

Which of the following is INCORRECT with respect to file systems?

A logical record is concerned with efficient storage of information in the secondary storage devices.

The efficiency of a file system depends on how efficiently operations such as retrieve, insert, update, delete may be performed on the information stored in the file.

At the physical level, pointer or hashed address scheme may be employed to provide a certain degree of data independence at the user level.

Some physical organisations use pointers to record blocks to locate records on disk.

39 / 50

A collection of related data is

Relational model

Database

Data

Logical model

40 / 50

User rights information is stored in

Catalog

Buffer

Physical database

Logical database

41 / 50

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

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

by splitting each table into three

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.

42 / 50

Which of the following statements is NOT correct?

The functional dependency ProjNo -> DeptNo holds over R.

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

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

The functional dependency EmpNo -> DeptNo holds over R.

43 / 50

Identify the correct statement with respect to normalization.

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.

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

44 / 50

Which feature of database provides conversion from inconsistent state of DB to a consistent state ensuring
minimum data loss?

Recovery service

Authorization service

User accessible catalog

Data processing

45 / 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 relation must be distinct.

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.

46 / 50

Which of the following is true about relational schema?

Contains only derived attributes.

The sequence of columns is significant

Values are atomic.

The sequence of rows is significant.

47 / 50

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

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

by splitting each table into three

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

48 / 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 B and C.

Only A.

Only C.

Only A and B.

49 / 50

Which of the following concepts is applicable with respect to 2NF?

Any kind of dependency

Non-transitive dependency

Transitive dependency

Full functional dependency

50 / 50

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

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

The domain of attribute must include only atomic values.

Every non-key attribute is partially dependent on super key

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

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