CS403 Midterm Online Quiz

2 votes, 5 avg

CS403-Midterm

1 / 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

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

2 / 50

Which of the following is true about NOT NULL constraint?

enforce domain integrity

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

limit the values that can be placed in a column

enforces the uniqueness of the values in a set of columns

3 / 50

Identify the correct way to implement one-to-one relationship in 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.

by creating two separate tables

4 / 50

Controlling redundancy in a database management system DOES NOT help to

avoid duplication

avoid unauthorised access to data

avoid inconsistency among data

avoid unnecessary wastage of storage space

5 / 50

Which of the following is not true about relational tables?

Each column must have a unique name.

The sequence of rows is significant.

Each row is unique.

Column values are of the same kind.

6 / 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

A and B

Only A

7 / 50

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

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

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.

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

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

8 / 50

Which of the following statements is NOT correct?

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.

The functional dependency DeptNo -> ProjNo holds over R.

9 / 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

10 / 50

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

allow any actions that would destroy links between tables

unique identifier for a row within a database table.

enforces that the column will only accept null values.

limit the values that can be placed in a column.

11 / 50

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

Student – Instructor

Student ∩ Instructor

Instructor – Student

Instructor ÷ Student

12 / 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)

13 / 50

Which of the following statements is NOT correct?

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.

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

14 / 50

Which of the following constraints enforces entity integrity?

NOT NULL

PRIMARY KEY

FOREIGN KEY

CHECK

15 / 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

16 / 50

User rights information is stored in

Catalog

Logical database

Physical database

Buffer

17 / 50

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

DBMS

Data model

Database

Data

18 / 50

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

Non-transitive dependency

Full functional dependency

Any kind of dependency

Transitive dependency

19 / 50

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

CHECK

UNIQUE

FOREIGN KEY

NOT NULL

20 / 50

Which of the following is not a benefit of normalization?

Minimize deletion anomolies

Minimize insertion anomolies

Maximize redundancy

Minimize updation anomolies

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 C.

Only A.

Only A and B.

Only B and C.

22 / 50

A software package designed to store and manage databases

Database

Data

DBMS

Data model

23 / 50

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

specialization

completeness

inheritance

uniqueness

24 / 50

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

Allocation of storage locations and data structures

Establishing standards and procedures for database systems

Communicating with database users

Planning, designing and implementing database systems

25 / 50

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

1:01

1:M

M:M

Ternary

26 / 50

User rights information is stored in

Catalog

Logical database

Buffer

Physical database

27 / 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.

by splitting each table into three

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

28 / 50

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

index

determinant

foreign key

primary key

29 / 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.

30 / 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

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

by splitting each table into three

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

31 / 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 FD3 violates 3NF.

The relation Interview is in BCNF.

The FD2 violates 2NF.

32 / 50

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

Data processing

Authorization service

Recovery service

User accessible catalog

33 / 50

Identify the correct statement.

Entity integrity constraints are specified on individual relations.

Entity integrity constraints are specified between weak entities.

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.

34 / 50

statement among the following on the above diagram.

The diagram depicts existence dependencies.

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

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

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

35 / 50

Which of the following constraints enforces entity integrity?

CHECK

PRIMARY KEY

FOREIGN KEY

NOT NULL

36 / 50

A database system allows the following EXCEPT

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

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.

37 / 50

The ER- data model is an example of:

Relational database

Physical database

Conceptual database

Logical database

38 / 50

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

Data model

Data

DBMS

Database

39 / 50

Identify the correct statement.

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

Referential integrity constraints are specified between entities having recursive relationships.

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.

40 / 50

Identify the INCORRECT statement among the given

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.

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.

41 / 50

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

Application Programmer

End User

Database Administrator

Database Designer

42 / 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 between weak entities.

Entity integrity constraints are specified on individual relations.

43 / 50

A collection of related data is

Logical model

Data

Relational model

Database

44 / 50

Which of the following constraints enforces entity integrity?

PRIMARY KEY

FOREIGN KEY

NOT NULL

CHECK

45 / 50

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

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

all tuples in a particular relation may have different attributes.

all tuples in a relation must be distinct.

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

46 / 50

The ER- data model is an example of:

Conceptual database

Logical database

Relational database

Physical database

47 / 50

Which of the following is true about relational schema?

Values are atomic.

The sequence of rows is significant.

Contains only derived attributes.

The sequence of columns is significant

48 / 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

49 / 50

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

weak

binary

ternary

unary

50 / 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.

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