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.

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.

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

2 / 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.

3 / 50

Which of the following is not true about relational tables?

The sequence of rows is significant.

Each column must have a unique name.

Column values are of the same kind.

Each row is unique.

4 / 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.

5 / 50

statement among the following on the above diagram.

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

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

The diagram depicts existence dependencies.

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

6 / 50

User rights information is stored in

Catalog

Logical database

Physical database

Buffer

7 / 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)

one process (which represents the entire system)

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

8 / 50

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

inheritance

specialization

completeness

uniqueness

9 / 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.

A logical record is concerned with efficient storage of information in the secondary storage devices.

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

Some physical organisations use pointers to record blocks to locate records on disk.

10 / 50

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

Instructor – Student

Instructor ÷ Student

Student ∩ Instructor

Student – Instructor

11 / 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.

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

12 / 50

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

1:01

M:M

1:M

Ternary

13 / 50

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

Data model

Database

DBMS

Data

14 / 50

The ER- data model is an example of:

Conceptual database

Relational database

Physical database

Logical database

15 / 50

Which of the following constraints enforces entity integrity?

CHECK

FOREIGN KEY

PRIMARY KEY

NOT NULL

16 / 50

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

hardware

software

input and output

computer infrastructure

17 / 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)

all sources/sinks (external entities)

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

18 / 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 C.

Only B and C.

Only A.

Only A and B.

19 / 50

The ER- data model is an example of:

Physical database

Relational database

Conceptual database

Logical database

20 / 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.

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

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.

21 / 50

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

determinant

primary key

index

foreign key

22 / 50

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

Data processing

Authorization service

User accessible catalog

Recovery service

23 / 50

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

unary

weak

binary

ternary

24 / 50

Which of the following is true about relational schema?

Contains only derived attributes.

Values are atomic.

The sequence of columns is significant

The sequence of rows is significant.

25 / 50

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

A recursive relationship

An identifying relationship

A ternary relationship

A binary relationship

26 / 50

Which of the following statements is NOT correct?

The functional dependency DeptNo -> ProjNo holds over R.

The functional dependency EmpNo -> DeptNo holds over R.

The functional dependency ProjNo -> DeptNo holds over R.

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

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

A and B

B and C

28 / 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 check whether the primary key values are unique.

Referential integrity constraints are specified between entities having recursive relationships.

29 / 50

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

Database

Data

Data model

DBMS

30 / 50

Which of the following is correct?

The relation Interview is in BCNF.

The FD2 violates 2NF.

The FD3 violates 3NF.

The relation Interview is in 3NF

31 / 50

Only A

B and C

Only B

A and B

32 / 50

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

Communicating with database users

Allocation of storage locations and data structures

Planning, designing and implementing database systems

Establishing standards and procedures for database systems

33 / 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

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

34 / 50

A software package designed to store and manage databases

Data model

Database

DBMS

Data

35 / 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.

36 / 50

A collection of related data is

Data

Relational model

Database

Logical model

37 / 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.

38 / 50

User rights information is stored in

Physical database

Logical database

Catalog

Buffer

39 / 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) -> ProjNo holds over R.

The functional dependency EmpNo -> DeptNo holds over R.

40 / 50

Which of the following constraints enforces entity integrity?

CHECK

FOREIGN KEY

PRIMARY KEY

NOT NULL

41 / 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

42 / 50

Select the correct statement about the ANSI/SPARC architecture.

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.

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

43 / 50

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

by creating two separate tables

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.

44 / 50

Which of the following constraints enforces entity integrity?

NOT NULL

FOREIGN KEY

CHECK

PRIMARY KEY

45 / 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.

46 / 50

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

enforces that the column will only accept null values.

unique identifier for a row within a database table.

allow any actions that would destroy links between tables

limit the values that can be placed in a column.

47 / 50

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

inheritance

completeness

uniqueness

specialization

48 / 50

Which of the following is not a benefit of normalization?

Maximize redundancy

Minimize deletion anomolies

Minimize insertion anomolies

Minimize updation anomolies

49 / 50

Which of the following is true about relational schema?

Values are atomic.

The sequence of rows is significant.

Contains only derived attributes.

The sequence of columns is significant

50 / 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.

all tuples in a relation must be distinct.

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

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