CS403 Midterm Online Quiz

2 votes, 5 avg

CS403-Midterm

1 / 50

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

Database Administrator

End User

Application Programmer

Database Designer

2 / 50

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

completeness

specialization

uniqueness

inheritance

3 / 50

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

limit the values that can be placed in a column.

allow any actions that would destroy links between tables

unique identifier for a row within a database table.

enforces that the column will only accept null values.

4 / 50

statement among the following on the above diagram.

The participation of Z in the Y relationship type is partial.

The diagram depicts existence dependencies.

The participation of X in the Y relationship type is total.

The relationship type Y is of cardinality ratio 1 : N.

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 statements is NOT correct?

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.

The functional dependency ProjNo -> DeptNo holds over R.

7 / 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, ProjNo) -> DeptNo holds over R.

The functional dependency EmpNo -> DeptNo holds over R.

8 / 50

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

Database

Data model

Data

DBMS

9 / 50

User rights information is stored in

Buffer

Physical database

Catalog

Logical database

10 / 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

11 / 50

Which of the following is true about NOT NULL constraint?

enforce domain integrity

limit the values that can be placed in a column

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

12 / 50

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

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

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

The domain of attribute must include only atomic values.

Every non-key attribute is partially dependent on super key

13 / 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

14 / 50

The ER- data model is an example of:

Relational database

Physical database

Logical database

Conceptual database

15 / 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.

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

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

16 / 50

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

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.

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.

17 / 50

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

specialization

uniqueness

completeness

inheritance

18 / 50

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

hardware

input and output

software

computer infrastructure

19 / 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

20 / 50

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

Ternary

1:01

1:M

M:M

21 / 50

Which of the following constraints enforces entity integrity?

FOREIGN KEY

NOT NULL

PRIMARY KEY

CHECK

22 / 50

Which of the following constraints enforces entity integrity?

CHECK

FOREIGN KEY

NOT NULL

PRIMARY KEY

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 B

Only A

B and C

A and B

24 / 50

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

Communicating with database users

Planning, designing and implementing database systems

Allocation of storage locations and data structures

Establishing standards and procedures for database systems

25 / 50

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

DBMS

Data

Database

Data model

26 / 50

Identify the correct statement.

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.

Entity integrity constraints are specified on individual relations.

27 / 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.

28 / 50

Which of the following constraints enforces entity integrity?

PRIMARY KEY

CHECK

FOREIGN KEY

NOT NULL

29 / 50

Which of the following statements is NOT correct?

The functional dependency ProjNo -> DeptNo holds over R.

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.

30 / 50

Identify the correct statement with respect to normalization.

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.

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.

31 / 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.

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 may be an object with a physical existence like a car, a house or an Employee.

32 / 50

A software package designed to store and manage databases

Database

Data

Data model

DBMS

33 / 50

Which of the following is not a benefit of normalization?

Minimize insertion anomolies

Minimize deletion anomolies

Maximize redundancy

Minimize updation anomolies

34 / 50

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

weak

unary

ternary

binary

35 / 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

36 / 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.

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.

all tuples in a relation must be distinct.

37 / 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 are specified on individual relations.

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

38 / 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.

39 / 50

Which of the following is correct?

The FD2 violates 2NF.

The FD3 violates 3NF.

The relation Interview is in BCNF.

The relation Interview is in 3NF

40 / 50

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

Full functional dependency

Any kind of dependency

Non-transitive dependency

Transitive dependency

41 / 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

42 / 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.

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

43 / 50

Which of the following is true about relational schema?

Contains only derived attributes.

The sequence of columns is significant

Values are atomic.

The sequence of rows is significant.

44 / 50

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

CHECK

UNIQUE

FOREIGN KEY

NOT NULL

45 / 50

Which of the following is not true about relational tables?

Each row is unique.

Column values are of the same kind.

Each column must have a unique name.

The sequence of rows is significant.

46 / 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.

47 / 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 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.

48 / 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

49 / 50

A database system allows the following EXCEPT

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

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.

50 / 50

A and B

Only B

Only A

B and C

Your score is

The average score is 22%