CS403 Midterm Online Quiz

2 votes, 5 avg

CS403-Midterm

1 / 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

A and B

Only B

2 / 50

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

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.

Every non-key attribute is partially dependent on super key

The domain of attribute must include only atomic values.

4 / 50

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

End User

Application Programmer

Database Designer

Database Administrator

5 / 50

A collection of related data is

Database

Data

Relational model

Logical model

6 / 50

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

NOT NULL

CHECK

FOREIGN KEY

UNIQUE

7 / 50

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

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

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

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

8 / 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.

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.

9 / 50

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

inheritance

uniqueness

specialization

completeness

10 / 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

limit the values that can be placed in a column

enforces the uniqueness of the values in a set of columns

enforce domain integrity

11 / 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

12 / 50

User rights information is stored in

Physical database

Buffer

Logical database

Catalog

13 / 50

Which of the following constraints enforces entity integrity?

CHECK

NOT NULL

FOREIGN KEY

PRIMARY KEY

14 / 50

Identify the correct statement.

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

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.

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

15 / 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.

16 / 50

Which of the following constraints enforces entity integrity?

CHECK

NOT NULL

FOREIGN KEY

PRIMARY KEY

17 / 50

Which of the following constraints enforces entity integrity?

PRIMARY KEY

NOT NULL

FOREIGN KEY

CHECK

18 / 50

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

unique identifier for a row within a database table.

limit the values that can be placed in a column.

enforces that the column will only accept null values.

allow any actions that would destroy links between tables

19 / 50

The ER- data model is an example of:

Physical database

Logical database

Conceptual database

Relational database

20 / 50

User rights information is stored in

Logical database

Catalog

Buffer

Physical database

21 / 50

Structural constraints of a relationship type refer to

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.

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

22 / 50

Which of the following statements is NOT correct?

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.

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

23 / 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.

24 / 50

Which of the following is not a benefit of normalization?

Maximize redundancy

Minimize updation anomolies

Minimize insertion anomolies

Minimize deletion anomolies

25 / 50

Select the correct statement about the ANSI/SPARC architecture.

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

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

26 / 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

27 / 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.

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.

28 / 50

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

binary

ternary

weak

unary

29 / 50

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

Logical data independence.

Concurrency control.

Physical data independence.

Functional dependency

30 / 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

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

31 / 50

Controlling redundancy in a database management system DOES NOT help to

avoid unauthorised access to data

avoid inconsistency among data

avoid duplication

avoid unnecessary wastage of storage space

32 / 50

Identify the correct statement.

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.

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

33 / 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 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.

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

34 / 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 specify that primary key values can be composite.

Entity integrity constraints are specified on individual relations.

35 / 50

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

Data

Database

Data model

DBMS

36 / 50

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

Any kind of dependency

Full functional dependency

Transitive dependency

Non-transitive dependency

37 / 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)

38 / 50

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

hardware

computer infrastructure

software

input and output

39 / 50

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

1:M

1:01

Ternary

M:M

40 / 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 (EmpNo, ProjNo) -> DeptNo holds over R.

The functional dependency ProjNo -> DeptNo holds over R.

41 / 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.

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

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

42 / 50

Which of the following is not true about relational tables?

Each column must have a unique name.

Each row is unique.

Column values are of the same kind.

The sequence of rows is significant.

43 / 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.

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.

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

44 / 50

A database system allows the following EXCEPT

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.

integration of data across multiple applications into a single application

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

any user to access all its data.

45 / 50

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

uniqueness

specialization

completeness

inheritance

46 / 50

Only B

A and B

B and C

Only A

47 / 50

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

Authorization service

Data processing

Recovery service

User accessible catalog

48 / 50

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

A recursive relationship

A ternary relationship

An identifying relationship

A binary relationship

49 / 50

Structural constraints of a relationship type refer to

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.

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.

50 / 50

The ER- data model is an example of:

Conceptual database

Physical database

Relational database

Logical database

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