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.

A and B

B and C

Only B

Only A

2 / 50

Which of the following is true about NOT NULL constraint?

enforce domain integrity

limit the values that can be placed in a column

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

3 / 50

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

M:M

1:M

1:01

Ternary

4 / 50

Which of the following constraints enforces entity integrity?

FOREIGN KEY

PRIMARY KEY

NOT NULL

CHECK

5 / 50

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

input and output

hardware

computer infrastructure

software

6 / 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 FD2 violates 2NF.

The relation Interview is in BCNF.

The relation Interview is in 3NF

The FD3 violates 3NF.

7 / 50

User rights information is stored in

Logical database

Physical database

Catalog

Buffer

8 / 50

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

Database

DBMS

Data

Data model

9 / 50

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

A recursive relationship

An identifying relationship

A binary relationship

A ternary relationship

10 / 50

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

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

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

11 / 50

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

Concurrency control.

Physical data independence.

Functional dependency

Logical data independence.

12 / 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.

13 / 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)

14 / 50

A software package designed to store and manage databases

Data

Data model

DBMS

Database

15 / 50

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

Authorization service

User accessible catalog

Recovery service

Data processing

16 / 50

The ER- data model is an example of:

Logical database

Conceptual database

Physical database

Relational database

17 / 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 and B.

Only A.

Only B and C.

18 / 50

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

Database Designer

End User

Application Programmer

Database Administrator

19 / 50

Which of the following is not a benefit of normalization?

Minimize deletion anomolies

Minimize insertion anomolies

Maximize redundancy

Minimize updation anomolies

20 / 50

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

Transitive dependency

Non-transitive dependency

Any kind of dependency

Full functional dependency

21 / 50

Which of the following constraints enforces entity integrity?

PRIMARY KEY

FOREIGN KEY

NOT NULL

CHECK

22 / 50

Identify the correct statement with respect to normalization.

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 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.

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

23 / 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 -> DeptNo holds over R.

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

24 / 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.

25 / 50

Structural constraints of a relationship type refer to

identifying the owner entity type relevant to a given entity type

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

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.

26 / 50

The ER- data model is an example of:

Conceptual database

Relational database

Logical database

Physical database

27 / 50

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

Planning, designing and implementing database systems

Establishing standards and procedures for database systems

Communicating with database users

Allocation of storage locations and data structures

28 / 50

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

determinant

primary key

index

foreign key

29 / 50

Which of the following is correct?

The relation Interview is in BCNF.

The FD3 violates 3NF.

The FD2 violates 2NF.

The relation Interview is in 3NF

30 / 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)

31 / 50

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

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

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

32 / 50

Select the correct statement about the ANSI/SPARC architecture.

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

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

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.

33 / 50

A database system allows the following EXCEPT

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.

integration of data across multiple applications into a single application

34 / 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.

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.

35 / 50

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

completeness

uniqueness

specialization

inheritance

36 / 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.

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

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

37 / 50

A collection of related data is

Relational model

Database

Logical model

Data

38 / 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

39 / 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.

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.

40 / 50

statement among the following on the above diagram.

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.

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

41 / 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 creating two separate tables

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

42 / 50

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

FOREIGN KEY

NOT NULL

UNIQUE

CHECK

43 / 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

44 / 50

Which of the following is true about relational schema?

The sequence of columns is significant

Contains only derived attributes.

The sequence of rows is significant.

Values are atomic.

45 / 50

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

binary

ternary

unary

weak

46 / 50

Which of the following is not true about relational tables?

Column values are of the same kind.

The sequence of rows is significant.

Each row is unique.

Each column must have a unique name.

47 / 50

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

Database

Data model

DBMS

Data

48 / 50

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

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

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

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.

49 / 50

Which of the following statements is NOT correct?

The functional dependency DeptNo -> ProjNo holds over R.

The functional dependency ProjNo -> DeptNo holds over R.

The functional dependency EmpNo -> DeptNo holds over R.

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

50 / 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.

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