CS403 Midterm Online Quiz

2 votes, 5 avg

CS403-Midterm

1 / 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.

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.

2 / 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

Data processing

Recovery service

3 / 50

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

Application Programmer

End User

Database Administrator

Database Designer

4 / 50

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

weak

unary

binary

ternary

5 / 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.

by creating two separate tables

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

6 / 50

Which of the following constraints enforces entity integrity?

PRIMARY KEY

CHECK

NOT NULL

FOREIGN KEY

7 / 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

8 / 50

Which of the following constraints enforces entity integrity?

FOREIGN KEY

CHECK

PRIMARY KEY

NOT NULL

9 / 50

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

all sources/sinks (external entities)

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

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

one process (which represents the entire system)

10 / 50

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

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.

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.

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

11 / 50

Controlling redundancy in a database management system DOES NOT help to

avoid unnecessary wastage of storage space

avoid unauthorised access to data

avoid duplication

avoid inconsistency among data

12 / 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.

13 / 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 dependency reservation property at any cost whereas the lossless join property is sometimes sacrificed.

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.

14 / 50

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

Non-transitive dependency

Any kind of dependency

Transitive dependency

Full functional dependency

15 / 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

16 / 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 on individual relations.

Entity integrity constraints are specified between weak entities.

17 / 50

Structural constraints of a relationship type refer to

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

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

18 / 50

The ER- data model is an example of:

Physical database

Relational database

Logical database

Conceptual database

19 / 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.

20 / 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.

21 / 50

Which of the following is not true about relational tables?

The sequence of rows is significant.

Each column must have a unique name.

Column values are of the same kind.

Each row is unique.

22 / 50

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

NOT NULL

FOREIGN KEY

CHECK

UNIQUE

23 / 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 A

Only B

A and B

B and C

24 / 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, ProjNo) -> DeptNo holds over R

The functional dependency DeptNo -> ProjNo holds over R.

25 / 50

Select the correct statement among the following.

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

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

26 / 50

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

uniqueness

specialization

inheritance

completeness

27 / 50

Which of the following is correct?

The relation Interview is in 3NF

The FD2 violates 2NF.

The FD3 violates 3NF.

The relation Interview is in BCNF.

28 / 50

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

Data

Database

Data model

DBMS

29 / 50

Which of the following is true about relational schema?

Contains only derived attributes.

The sequence of rows is significant.

Values are atomic.

The sequence of columns is significant

30 / 50

Which of the following is true about relational schema?

The sequence of columns is significant

Values are atomic.

The sequence of rows is significant.

Contains only derived attributes.

31 / 50

The ER- data model is an example of:

Conceptual database

Physical database

Relational database

Logical database

32 / 50

A software package designed to store and manage databases

DBMS

Data model

Database

Data

33 / 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

34 / 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 are specified between weak entities.

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

35 / 50

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

DBMS

Database

Data

Data model

36 / 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.

37 / 50

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

specialization

inheritance

completeness

uniqueness

38 / 50

User rights information is stored in

Logical database

Buffer

Physical database

Catalog

39 / 50

Only B

B and C

A and B

Only A

40 / 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 FD2 violates 2NF.

The relation Interview is in BCNF.

41 / 50

Which of the following is not a benefit of normalization?

Minimize insertion anomolies

Minimize updation anomolies

Maximize redundancy

Minimize deletion anomolies

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 fully functionally dependent on primary key

Every non-key attribute is partially dependent on super key

43 / 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.

44 / 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 particular relation may have different attributes.

all tuples in a relation must be distinct.

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

45 / 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.

46 / 50

Which of the following constraints enforces entity integrity?

PRIMARY KEY

CHECK

FOREIGN KEY

NOT NULL

47 / 50

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

foreign key

primary key

index

determinant

48 / 50

Which of the following is INCORRECT statement concerning the database design process?

By referring to a high level data model, it is possible to understand the data requirements of the users, entity types, relationships and constraints

Transformation of the high level data model into the implementation data model is called logical design or data model mapping

During the logical design phase of internal storage structures, access paths and file organization for the database files are specified

During requirements collection and analysis phase, one can gather the data requirements of database users.

49 / 50

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

Instructor ÷ Student

Instructor – Student

Student – Instructor

Student ∩ Instructor

50 / 50

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

software

computer infrastructure

input and output

hardware

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The average score is 22%