CS403 Midterm Online Quiz

2 votes, 5 avg

CS403-Midterm

1 / 50

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

specialization

completeness

inheritance

uniqueness

2 / 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

3 / 50

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

Data

DBMS

Data model

Database

4 / 50

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

Database

Data

DBMS

Data model

5 / 50

The ER- data model is an example of:

Logical database

Physical database

Relational database

Conceptual database

6 / 50

Which of the following is not a benefit of normalization?

Minimize updation anomolies

Maximize redundancy

Minimize deletion anomolies

Minimize insertion anomolies

7 / 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.

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

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

8 / 50

Which of the following is true about relational schema?

The sequence of rows is significant.

The sequence of columns is significant

Contains only derived attributes.

Values are atomic.

9 / 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 3NF

The FD3 violates 3NF.

The relation Interview is in BCNF.

10 / 50

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

limit the values that can be placed in a column.

enforces that the column will only accept null values.

allow any actions that would destroy links between tables

unique identifier for a row within a database table.

11 / 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.

12 / 50

Which of the following is true about NOT NULL constraint?

limit the values that can be placed in a column

enforces the uniqueness of the values in a set of columns

enforce domain integrity

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

13 / 50

Which of the following constraints enforces entity integrity?

PRIMARY KEY

FOREIGN KEY

CHECK

NOT NULL

14 / 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.

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.

15 / 50

A collection of related data is

Logical model

Data

Database

Relational model

16 / 50

Which of the following constraints enforces entity integrity?

PRIMARY KEY

NOT NULL

FOREIGN KEY

CHECK

17 / 50

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

Recovery service

Data processing

Authorization service

User accessible catalog

18 / 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 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.

19 / 50

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

A binary relationship

A ternary relationship

An identifying relationship

A recursive relationship

20 / 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 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.

21 / 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 and B.

Only B and C.

Only C.

Only A.

22 / 50

User rights information is stored in

Physical database

Buffer

Catalog

Logical database

23 / 50

Identify the correct statement.

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 check whether an attribute value lies in the given range.

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

Referential integrity constraints are specified between entities having recursive relationships.

24 / 50

Identify the correct statement.

Entity integrity constraints are specified between weak entities.

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.

25 / 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 B

Only A

A and B

26 / 50

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

1:01

1:M

Ternary

M:M

27 / 50

statement among the following on the above diagram.

The diagram depicts existence dependencies.

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

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

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

28 / 50

The ER- data model is an example of:

Relational database

Physical database

Logical database

Conceptual database

29 / 50

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

Physical data independence.

Functional dependency

Concurrency control.

Logical data independence.

30 / 50

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

unary

weak

ternary

binary

31 / 50

Which of the following is true for the relational model?

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

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.

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

32 / 50

Controlling redundancy in a database management system DOES NOT help to

avoid unauthorised access to data

avoid inconsistency among data

avoid unnecessary wastage of storage space

avoid duplication

33 / 50

Which of the following statements is NOT correct?

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

34 / 50

Select the correct statement about the ANSI/SPARC architecture.

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.

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.

35 / 50

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

Every non-key attribute is partially dependent on super key

The domain of attribute must include only atomic values.

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

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

36 / 50

B and C

A and B

Only B

Only A

37 / 50

Which of the following is true about relational schema?

The sequence of columns is significant

The sequence of rows is significant.

Contains only derived attributes.

Values are atomic.

38 / 50

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

Communicating with database users

Allocation of storage locations and data structures

Establishing standards and procedures for database systems

Planning, designing and implementing database systems

39 / 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)

all sources/sinks (external entities)

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

40 / 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

41 / 50

Which of the following is correct?

The FD2 violates 2NF.

The relation Interview is in 3NF

The FD3 violates 3NF.

The relation Interview is in BCNF.

42 / 50

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

Non-transitive dependency

Full functional dependency

Transitive dependency

Any kind of dependency

43 / 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.·

44 / 50

A software package designed to store and manage databases

Data model

Data

Database

DBMS

45 / 50

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

UNIQUE

FOREIGN KEY

CHECK

NOT NULL

46 / 50

Which of the following is not true about relational tables?

The sequence of rows is significant.

Column values are of the same kind.

Each column must have a unique name.

Each row is unique.

47 / 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.

integration of data across multiple applications into a single application

any user to access all its data.

48 / 50

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

all sources/sinks (external entities)

one process (which represents the entire system)

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

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

49 / 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.

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

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

50 / 50

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

Database Designer

Database Administrator

End User

Application Programmer

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