CS403 Midterm Online Quiz

2 votes, 5 avg

CS403-Midterm

1 / 50

Which of the following constraints enforces entity integrity?

FOREIGN KEY

CHECK

NOT NULL

PRIMARY KEY

2 / 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 FD3 violates 3NF.

The relation Interview is in BCNF.

The FD2 violates 2NF.

The relation Interview is in 3NF

3 / 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.

A and B

Only B

B and C

Only A

4 / 50

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

input and output

hardware

computer infrastructure

software

5 / 50

A collection of related data is

Logical model

Data

Database

Relational model

6 / 50

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

Database

DBMS

Data

Data model

7 / 50

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

specialization

completeness

inheritance

uniqueness

8 / 50

The ER- data model is an example of:

Conceptual database

Logical database

Relational database

Physical database

9 / 50

Which of the following is a correct way to implement one-to-many relationship while designing tables?

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

by splitting each table into three

as a single table and rarely as two tables with primary and foreign key relationships

10 / 50

User rights information is stored in

Buffer

Physical database

Logical database

Catalog

11 / 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

12 / 50

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

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

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

13 / 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

14 / 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.

15 / 50

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

Recovery service

Data processing

Authorization service

User accessible catalog

16 / 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 holds over R.

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

17 / 50

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

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)

all sources/sinks (external entities)

18 / 50

Controlling redundancy in a database management system DOES NOT help to

avoid unnecessary wastage of storage space

avoid duplication

avoid inconsistency among data

avoid unauthorised access to data

19 / 50

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

Allocation of storage locations and data structures

Establishing standards and procedures for database systems

Communicating with database users

Planning, designing and implementing database systems

20 / 50

Which of the following is a correct way to implement one-to-many relationship while designing tables?

using a junction table with the keys from both the tables forming the composite primary key of the junction table.

by splitting each table into three

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.

21 / 50

Structural constraints of a relationship type refer to

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.

identifying the owner entity type relevant to a given entity type

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

22 / 50

Identify the correct statement with respect to normalization.

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.

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

23 / 50

A software package designed to store and manage databases

Data

Database

Data model

DBMS

24 / 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

25 / 50

The ER- data model is an example of:

Logical database

Physical database

Conceptual database

Relational database

26 / 50

Which of the following is true about NOT NULL constraint?

limit the values that can be placed in a column

enforce domain integrity

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

27 / 50

User rights information is stored in

Buffer

Physical database

Logical database

Catalog

28 / 50

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

1:01

1:M

M:M

Ternary

29 / 50

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

uniqueness

inheritance

completeness

specialization

30 / 50

Which of the following statements is NOT correct?

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.

The functional dependency ProjNo -> DeptNo holds over R.

31 / 50

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

Database

DBMS

Data model

Data

32 / 50

Which of the following is not a benefit of normalization?

Minimize updation anomolies

Maximize redundancy

Minimize deletion anomolies

Minimize insertion anomolies

33 / 50

Which of the following is correct?

The FD2 violates 2NF.

The relation Interview is in BCNF.

The relation Interview is in 3NF

The FD3 violates 3NF.

34 / 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 C.

Only A.

Only A and B.

35 / 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 DeptNo -> ProjNo holds over R.

The functional dependency EmpNo -> DeptNo holds over R.

36 / 50

Identify the INCORRECT statement among the given

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.

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.

37 / 50

A database system allows the following EXCEPT

integration of data across multiple applications into a single application

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

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.

38 / 50

Select the correct statement among the following.

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

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.

39 / 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 diagram depicts existence dependencies.

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

40 / 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.

unique identifier for a row within a database table.

enforces that the column will only accept null values.

41 / 50

Which of the following is not true about relational tables?

Column values are of the same kind.

Each column must have a unique name.

Each row is unique.

The sequence of rows is significant.

42 / 50

Which of the following constraints enforces entity integrity?

FOREIGN KEY

NOT NULL

PRIMARY KEY

CHECK

43 / 50

Which of the following is true about relational schema?

Contains only derived attributes.

The sequence of rows is significant.

The sequence of columns is significant

Values are atomic.

44 / 50

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

CHECK

FOREIGN KEY

NOT NULL

UNIQUE

45 / 50

Identify the correct statement.

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

Referential integrity constraints check whether an attribute value lies in the given range.

Referential integrity constraints are specified between entities having recursive relationships.

When Referential integrity rules are enforced, a tuple in one relation that refers to another relation must refer to an existing tuple.

46 / 50

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

one process (which represents the entire system)

all sources/sinks (external entities)

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

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

47 / 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.

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

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

48 / 50

Identify the correct statement.

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.

Entity integrity constraints are specified between weak entities.

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.

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.

50 / 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

Your score is

The average score is 22%