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) -> ProjNo holds over R.

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

The functional dependency EmpNo -> DeptNo holds over R.

The functional dependency ProjNo -> DeptNo holds over R.

2 / 50

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

Concurrency control.

Logical data independence.

Physical data independence.

Functional dependency

3 / 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.

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

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

4 / 50

Which of the following is not true about relational tables?

The sequence of rows is significant.

Each row is unique.

Each column must have a unique name.

Column values are of the same kind.

5 / 50

User rights information is stored in

Catalog

Buffer

Physical database

Logical database

6 / 50

Controlling redundancy in a database management system DOES NOT help to

avoid unauthorised access to data

avoid duplication

avoid unnecessary wastage of storage space

avoid inconsistency among data

7 / 50

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

Data

Data model

Database

DBMS

8 / 50

statement among the following on the above diagram.

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.

The diagram depicts existence dependencies.

9 / 50

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

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.

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.

10 / 50

Which of the following constraints enforces entity integrity?

PRIMARY KEY

NOT NULL

CHECK

FOREIGN KEY

11 / 50

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

primary key

index

foreign key

determinant

12 / 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.

13 / 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

14 / 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

Only A

Only B

B and C

15 / 50

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

by splitting each table into three

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

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

16 / 50

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

Student – Instructor

Instructor – Student

Student ∩ Instructor

Instructor ÷ Student

17 / 50

Identify the correct statement.

Entity integrity constraints are specified on individual relations.

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

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.

18 / 50

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

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)

all sources/sinks (external entities)

19 / 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.

20 / 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.

21 / 50

Identify the correct statement.

Referential integrity constraints are specified between entities having recursive relationships.

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.

22 / 50

Which of the following is not a benefit of normalization?

Minimize insertion anomolies

Minimize updation anomolies

Minimize deletion anomolies

Maximize redundancy

23 / 50

Which of the following statements is NOT correct?

The functional dependency ProjNo -> DeptNo holds over R.

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

The functional dependency EmpNo -> DeptNo holds over R.

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

24 / 50

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

End User

Database Administrator

Database Designer

Application Programmer

25 / 50

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

hardware

input and output

computer infrastructure

software

26 / 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.

27 / 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.

Only A and B.

Only C.

Only B and C.

28 / 50

A software package designed to store and manage databases

Database

Data model

DBMS

Data

29 / 50

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

Full functional dependency

Non-transitive dependency

Transitive dependency

Any kind of dependency

30 / 50

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

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.·

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

31 / 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.

32 / 50

Identify the correct statement with respect to normalization.

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.

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

33 / 50

Which of the following is true about relational schema?

The sequence of rows is significant.

Values are atomic.

The sequence of columns is significant

Contains only derived attributes.

34 / 50

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

M:M

1:M

Ternary

1:01

35 / 50

The ER- data model is an example of:

Physical database

Logical database

Relational database

Conceptual database

36 / 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.

Any given database has many conceptual schemas and one physical schema, but it has only one external schemas.

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

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

37 / 50

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

enforces that the column will only accept null values.

limit the values that can be placed in a column.

unique identifier for a row within a database table.

allow any actions that would destroy links between tables

38 / 50

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

ternary

unary

binary

weak

39 / 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

40 / 50

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

Data

Database

DBMS

Data model

41 / 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.

42 / 50

Which of the following constraints enforces entity integrity?

PRIMARY KEY

CHECK

FOREIGN KEY

NOT NULL

43 / 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.

44 / 50

Which of the following statements is NOT correct?

The functional dependency EmpNo -> DeptNo holds over R.

The functional dependency DeptNo -> ProjNo holds over R.

The functional dependency ProjNo -> DeptNo holds over R.

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

45 / 50

Which of the following is true for the relational model?

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.

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

46 / 50

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

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.

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

47 / 50

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

Communicating with database users

Planning, designing and implementing database systems

Establishing standards and procedures for database systems

Allocation of storage locations and data structures

48 / 50

Which of the following is correct?

The relation Interview is in BCNF.

The relation Interview is in 3NF

The FD2 violates 2NF.

The FD3 violates 3NF.

49 / 50

Which of the following is true about NOT NULL constraint?

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

enforces the uniqueness of the values in a set of columns

limit the values that can be placed in a column

enforce domain integrity

50 / 50

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

one process (which represents the entire system)

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)

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The average score is 22%