CS403 Midterm Online Quiz

2 votes, 5 avg

CS403-Midterm

1 / 50

Identify the INCORRECT statement among the given

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

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.

Age can be considered as a single value attribute of a person.

2 / 50

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

A binary relationship

A ternary relationship

A recursive relationship

An identifying relationship

3 / 50

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

Any kind of dependency

Non-transitive dependency

Transitive dependency

Full functional dependency

4 / 50

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

foreign key

determinant

index

primary key

5 / 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.

enforces that the column will only accept null values.

unique identifier for a row within a database table.

6 / 50

User rights information is stored in

Catalog

Logical database

Buffer

Physical database

7 / 50

The ER- data model is an example of:

Physical database

Relational database

Logical database

Conceptual database

8 / 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.

9 / 50

Which of the following is true about NOT NULL constraint?

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

limit the values that can be placed in a column

10 / 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

any user to access all its data.

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.

11 / 50

Select the correct statement about the ANSI/SPARC architecture.

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

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.

The external level is not concerned with individual user perceptions, while the conceptual level is concerned with a community user perception.

12 / 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.

13 / 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.

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

all tuples in a relation must be distinct.

14 / 50

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

Data model

Database

DBMS

Data

15 / 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.

16 / 50

Which of the following statements is NOT correct?

The functional dependency 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.

17 / 50

Which of the following is correct?

The FD3 violates 3NF.

The relation Interview is in 3NF

The FD2 violates 2NF.

The relation Interview is in BCNF.

18 / 50

Identify the correct statement.

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.

Entity integrity constraints are specified on individual relations.

19 / 50

A collection of related data is

Database

Data

Relational model

Logical model

20 / 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 on individual relations.

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

Entity integrity constraints are specified between weak entities.

21 / 50

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

specialization

inheritance

uniqueness

completeness

22 / 50

A software package designed to store and manage databases

Database

Data

Data model

DBMS

23 / 50

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

uniqueness

completeness

specialization

inheritance

24 / 50

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

FOREIGN KEY

UNIQUE

CHECK

NOT NULL

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

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

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

26 / 50

Controlling redundancy in a database management system DOES NOT help to

avoid inconsistency among data

avoid unauthorised access to data

avoid duplication

avoid unnecessary wastage of storage space

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.

Only B

Only A

B and C

A and B

28 / 50

Which of the following is not true about relational tables?

Column values are of the same kind.

Each row is unique.

The sequence of rows is significant.

Each column must have a unique name.

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.

Logical data independence.

Functional dependency

Concurrency control.

30 / 50

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

1:01

M:M

Ternary

1:M

31 / 50

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

User accessible catalog

Recovery service

Authorization service

Data processing

32 / 50

The ER- data model is an example of:

Logical database

Physical database

Relational database

Conceptual database

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

Select the correct statement among the following.

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.

Role names are not technically necessary in relationship types when all the participating entity types are distinct.

When different entity types participate only once in a single relationship type it is called a recursive relationship

35 / 50

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

Allocation of storage locations and data structures

Communicating with database users

Planning, designing and implementing database systems

Establishing standards and procedures for database systems

36 / 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.

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

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

37 / 50

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

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

one process (which represents the entire system)

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

all sources/sinks (external entities)

38 / 50

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

unary

ternary

weak

binary

39 / 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

Instructor ÷ Student

Student ∩ Instructor

40 / 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 B and C.

Only A and B.

Only C.

41 / 50

B and C

Only B

Only A

A and B

42 / 50

Which of the following statements is NOT correct?

The functional dependency EmpNo -> DeptNo holds over R.

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

The functional dependency ProjNo -> DeptNo holds over R.

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

43 / 50

User rights information is stored in

Buffer

Physical database

Catalog

Logical database

44 / 50

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

Application Programmer

End User

Database Designer

Database Administrator

45 / 50

Which of the following constraints enforces entity integrity?

CHECK

NOT NULL

PRIMARY KEY

FOREIGN KEY

46 / 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.

47 / 50

Which of the following constraints enforces entity integrity?

CHECK

PRIMARY KEY

FOREIGN KEY

NOT NULL

48 / 50

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

The domain of attribute must include only atomic values.

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

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

Every non-key attribute is partially dependent on super key

49 / 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.

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

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.

50 / 50

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

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

Your score is

The average score is 22%