CS403 Midterm Online Quiz

2 votes, 5 avg

CS403-Midterm

1 / 50

Which of the following statements is NOT correct?

The functional dependency EmpNo -> DeptNo holds over R.

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.

2 / 50

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

Data

DBMS

Data model

Database

3 / 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

Only A

B and C

A and B

4 / 50

Which of the following constraints enforces entity integrity?

CHECK

PRIMARY KEY

NOT NULL

FOREIGN KEY

5 / 50

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

hardware

computer infrastructure

software

input and output

6 / 50

Which of the following is true for the relational model?

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

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

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

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

7 / 50

B and C

Only A

Only B

A and B

8 / 50

The ER- data model is an example of:

Logical database

Relational database

Conceptual database

Physical database

9 / 50

Which of the following is true about relational schema?

The sequence of columns is significant

Contains only derived attributes.

Values are atomic.

The sequence of rows is significant.

10 / 50

Which of the following is correct?

The FD2 violates 2NF.

The relation Interview is in BCNF.

The FD3 violates 3NF.

The relation Interview is in 3NF

11 / 50

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

Database

DBMS

Data

Data model

12 / 50

Identify the correct statement.

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

Entity integrity constraints are specified on individual relations.

Entity integrity constraints are specified between weak entities.

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

13 / 50

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

by creating two separate tables

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

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.

14 / 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 C.

Only A.

Only A and B.

Only B and C.

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

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.

16 / 50

Which of the following is not a benefit of normalization?

Minimize updation anomolies

Minimize insertion anomolies

Maximize redundancy

Minimize deletion anomolies

17 / 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

Student – Instructor

Instructor – Student

18 / 50

A software package designed to store and manage databases

Database

Data

DBMS

Data model

19 / 50

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

NOT NULL

CHECK

FOREIGN KEY

UNIQUE

20 / 50

A database system allows the following EXCEPT

integration of data across multiple applications into a single application

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.

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

21 / 50

Which of the following constraints enforces entity integrity?

FOREIGN KEY

PRIMARY KEY

CHECK

NOT NULL

22 / 50

As part of database naming conventions, attribute names should use suffixes such as ID, NUMBER or CODE for the _______.

primary key

determinant

index

foreign key

23 / 50

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

Transitive dependency

Any kind of dependency

Full functional dependency

Non-transitive dependency

24 / 50

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

by splitting each table into three

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

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

25 / 50

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

weak

ternary

binary

unary

26 / 50

Identify the INCORRECT statement among the given

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

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.

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

27 / 50

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

A ternary relationship

A binary relationship

An identifying relationship

A recursive relationship

28 / 50

User rights information is stored in

Catalog

Logical database

Buffer

Physical database

29 / 50

Which of the following is true about NOT NULL constraint?

enforce domain integrity

enforces the uniqueness of the values in a set of columns

limit the values that can be placed in a column

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

30 / 50

Controlling redundancy in a database management system DOES NOT help to

avoid unauthorised access to data

avoid unnecessary wastage of storage space

avoid inconsistency among data

avoid duplication

31 / 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.

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

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

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

32 / 50

Making a change to the conceptual schema of a database but not affecting the existing external schemas is an example of

Concurrency control.

Functional dependency

Physical data independence.

Logical data independence.

33 / 50

User rights information is stored in

Logical database

Physical database

Buffer

Catalog

34 / 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)

all sources/sinks (external entities)

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

35 / 50

Which of the following is not true about relational tables?

Each row is unique.

The sequence of rows is significant.

Column values are of the same kind.

Each column must have a unique name.

36 / 50

The ER- data model is an example of:

Physical database

Logical database

Relational database

Conceptual database

37 / 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.

38 / 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.

39 / 50

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

specialization

uniqueness

inheritance

completeness

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

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

41 / 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.

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.

by splitting each table into three

42 / 50

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

The domain of attribute must include only atomic values.

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

Every non-key attribute is partially dependent on super key

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

43 / 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.

unique identifier for a row within a database table.

enforces that the column will only accept null values.

44 / 50

Identify the correct statement.

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 on individual relations.

Entity integrity constraints are specified between weak entities.

45 / 50

Which of the following statements is NOT correct?

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

The functional dependency DeptNo -> ProjNo holds over R.

The functional dependency EmpNo -> DeptNo holds over R.

The functional dependency ProjNo -> DeptNo holds over R.

46 / 50

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

Database Administrator

End User

Database Designer

Application Programmer

47 / 50

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

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

one process (which represents the entire system)

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

all sources/sinks (external entities)

48 / 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

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

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

49 / 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.

50 / 50

Identify the correct statement.

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.

Referential integrity constraints are specified between entities having recursive relationships.

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