CS403 Midterm Online Quiz

2 votes, 5 avg

CS403-Midterm

1 / 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.

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.

2 / 50

Which of the following is not a benefit of normalization?

Minimize updation anomolies

Minimize deletion anomolies

Minimize insertion anomolies

Maximize redundancy

3 / 50

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

hardware

computer infrastructure

software

input and output

4 / 50

A database system allows the following EXCEPT

any user to access all its data.

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.

management and control of data towards an efficient working of an organisation.

5 / 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)

6 / 50

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

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

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

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

7 / 50

Which of the following constraints enforces entity integrity?

NOT NULL

PRIMARY KEY

CHECK

FOREIGN KEY

8 / 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

B and C

Only B

A and B

9 / 50

A software package designed to store and manage databases

Data

Data model

DBMS

Database

10 / 50

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

allow any actions that would destroy links between tables

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.

11 / 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

12 / 50

Structural constraints of a relationship type refer to

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.

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.

13 / 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 C.

Only A and B.

Only B and C.

14 / 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

15 / 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.

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

User rights information is stored in

Buffer

Logical database

Catalog

Physical database

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

the role that a participating entity from the entity type plays in each relationship instance.

19 / 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.

as a single table and rarely as two tables with primary 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.

20 / 50

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

specialization

uniqueness

completeness

inheritance

21 / 50

Which of the following is true about relational schema?

Values are atomic.

The sequence of columns is significant

Contains only derived attributes.

The sequence of rows is significant.

22 / 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.

23 / 50

Which of the following is true about relational schema?

The sequence of rows is significant.

Values are atomic.

Contains only derived attributes.

The sequence of columns is significant

24 / 50

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

specialization

inheritance

completeness

uniqueness

25 / 50

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

A binary relationship

An identifying relationship

A recursive relationship

A ternary relationship

26 / 50

Identify the correct statement.

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.

Referential integrity constraints are specified between entities having recursive relationships.

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

27 / 50

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.

28 / 50

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

Recovery service

Data processing

User accessible catalog

Authorization service

29 / 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

30 / 50

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

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)

all sources/sinks (external entities)

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

32 / 50

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

Transitive dependency

Non-transitive dependency

Full functional dependency

Any kind of dependency

33 / 50

Which of the following constraints enforces entity integrity?

PRIMARY KEY

CHECK

NOT NULL

FOREIGN KEY

34 / 50

Which of the following is true for the relational model?

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

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.

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

35 / 50

Identify the correct statement.

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

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.

36 / 50

Controlling redundancy in a database management system DOES NOT help to

avoid unauthorised access to data

avoid duplication

avoid inconsistency among data

avoid unnecessary wastage of storage space

37 / 50

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

Functional dependency

Physical data independence.

Logical data independence.

Concurrency control.

38 / 50

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

Data model

Data

Database

DBMS

39 / 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 BCNF.

The FD3 violates 3NF.

The FD2 violates 2NF.

The relation Interview is in 3NF

40 / 50

The ER- data model is an example of:

Logical database

Conceptual database

Physical database

Relational database

41 / 50

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

Establishing standards and procedures for database systems

Planning, designing and implementing database systems

Allocation of storage locations and data structures

Communicating with database users

42 / 50

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

Application Programmer

End User

Database Administrator

Database Designer

43 / 50

A collection of related data is

Data

Relational model

Logical model

Database

44 / 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.

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.·

by creating two separate tables

45 / 50

User rights information is stored in

Logical database

Catalog

Physical database

Buffer

46 / 50

Select the correct statement among the following.

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

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

47 / 50

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

index

primary key

foreign key

determinant

48 / 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.

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.

49 / 50

The ER- data model is an example of:

Conceptual database

Logical database

Physical database

Relational database

50 / 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.

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The average score is 22%