CS403 Midterm Online Quiz

2 votes, 5 avg

CS403-Midterm

1 / 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)

all sources/sinks (external entities)

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

2 / 50

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

all tuples in a particular relation may have different attributes.

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

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

all tuples in a relation must be distinct.

3 / 50

The ER- data model is an example of:

Relational database

Conceptual database

Logical database

Physical database

4 / 50

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

Transitive dependency

Any kind of dependency

Non-transitive dependency

Full functional dependency

5 / 50

A database system allows the following EXCEPT

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.

any user to access all its data.

6 / 50

User rights information is stored in

Catalog

Buffer

Physical database

Logical database

7 / 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 B and C.

Only A.

Only A and B.

Only C.

8 / 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.

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

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

9 / 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.

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.

10 / 50

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

index

primary key

determinant

foreign key

11 / 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

12 / 50

Which of the following is correct?

The FD3 violates 3NF.

The relation Interview is in BCNF.

The relation Interview is in 3NF

The FD2 violates 2NF.

13 / 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

14 / 50

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

A recursive relationship

A ternary relationship

An identifying relationship

A binary relationship

15 / 50

Which of the following is true about NOT NULL constraint?

limit the values that can be placed in a column

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

enforce domain integrity

enforces the uniqueness of the values in a set of columns

16 / 50

Select the correct statement about the ANSI/SPARC architecture.

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.

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.

17 / 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

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.

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

18 / 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)

19 / 50

User rights information is stored in

Physical database

Logical database

Catalog

Buffer

20 / 50

The ER- data model is an example of:

Physical database

Relational database

Conceptual database

Logical database

21 / 50

Which of the following constraints enforces entity integrity?

NOT NULL

FOREIGN KEY

PRIMARY KEY

CHECK

22 / 50

Controlling redundancy in a database management system DOES NOT help to

avoid inconsistency among data

avoid unnecessary wastage of storage space

avoid duplication

avoid unauthorised access to data

23 / 50

Which of the following is not a benefit of normalization?

Minimize updation anomolies

Maximize redundancy

Minimize insertion anomolies

Minimize deletion anomolies

24 / 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 are specified between weak entities.

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

Entity integrity constraints are specified on individual relations.

25 / 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 are specified between weak entities.

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

Entity integrity constraints are specified on individual relations.

26 / 50

A collection of related data is

Database

Relational model

Data

Logical model

27 / 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

A and B

Only A

Only B

28 / 50

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

Data model

DBMS

Database

Data

29 / 50

A software package designed to store and manage databases

DBMS

Data

Data model

Database

30 / 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.

31 / 50

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

CHECK

UNIQUE

NOT NULL

FOREIGN KEY

32 / 50

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

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

Every non-key attribute is partially dependent on super key

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

The domain of attribute must include only atomic values.

33 / 50

Which of the following is true about relational schema?

Values are atomic.

Contains only derived attributes.

The sequence of rows is significant.

The sequence of columns is significant

34 / 50

Which of the following constraints enforces entity integrity?

CHECK

NOT NULL

FOREIGN KEY

PRIMARY KEY

35 / 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

36 / 50

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

unary

binary

weak

ternary

37 / 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.

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.

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

38 / 50

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

User accessible catalog

Authorization service

Data processing

Recovery service

39 / 50

Which of the following statements is NOT correct?

The functional dependency (EmpNo, 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.

40 / 50

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

unique identifier for a row within a database table.

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

41 / 50

Structural constraints of a relationship type refer to

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 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.

42 / 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

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

43 / 50

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

Application Programmer

Database Administrator

Database Designer

End User

44 / 50

statement among the following on the above diagram.

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.

The diagram depicts existence dependencies.

45 / 50

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

computer infrastructure

software

input and output

hardware

46 / 50

Which of the following constraints enforces entity integrity?

NOT NULL

PRIMARY KEY

CHECK

FOREIGN KEY

47 / 50

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

Functional dependency

Logical data independence.

Physical data independence.

Concurrency control.

48 / 50

Structural constraints of a relationship type refer to

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.

identifying the owner entity type relevant to a given entity type

the constraints applicable in granting access to tables, columns and views in a database schema.

49 / 50

Which of the following is true for the relational model?

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.

Constraint is a rule that restricts the values in a database.

50 / 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.

Your score is

The average score is 22%