CS403 Midterm Online Quiz

2 votes, 5 avg

CS403-Midterm

1 / 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

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.

2 / 50

A software package designed to store and manage databases

DBMS

Data model

Database

Data

3 / 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 ProjNo -> DeptNo holds over R.

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

4 / 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 on individual relations.

Entity integrity constraints are specified between weak entities.

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

5 / 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 on individual relations.

Entity integrity constraints are specified between weak entities.

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

6 / 50

A collection of related data is

Data

Logical model

Relational model

Database

7 / 50

Which of the following is true for the relational model?

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

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

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.

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.

B and C

A and B

Only A

Only B

9 / 50

Which of the following is not a benefit of normalization?

Minimize updation anomolies

Minimize insertion anomolies

Maximize redundancy

Minimize deletion anomolies

10 / 50

Which of the following is true about relational schema?

The sequence of columns is significant

Contains only derived attributes.

Values are atomic.

The sequence of rows is significant.

11 / 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)

12 / 50

Which of the following constraints enforces entity integrity?

FOREIGN KEY

CHECK

PRIMARY KEY

NOT NULL

13 / 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 relation must be distinct.

all tuples in a particular relation may have different attributes.

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

14 / 50

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

A binary relationship

An identifying relationship

A ternary relationship

A recursive relationship

15 / 50

A database system allows the following EXCEPT

any user to access all its data.

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.

integration of data across multiple applications into a single application

16 / 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.

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

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

17 / 50

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

as a single table and rarely as two tables with primary 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

by splitting the data into two tables with primary key and foreign key relationships.

18 / 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.

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.

19 / 50

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

Application Programmer

Database Administrator

End User

Database Designer

20 / 50

Which of the following is correct?

The relation Interview is in 3NF

The FD2 violates 2NF.

The FD3 violates 3NF.

The relation Interview is in BCNF.

21 / 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.

22 / 50

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

unary

ternary

weak

binary

23 / 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.

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

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

24 / 50

Which of the following constraints enforces entity integrity?

CHECK

FOREIGN KEY

NOT NULL

PRIMARY KEY

25 / 50

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

uniqueness

completeness

inheritance

specialization

26 / 50

The ER- data model is an example of:

Logical database

Physical database

Conceptual database

Relational database

27 / 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.

28 / 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

29 / 50

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

Data

Data model

DBMS

Database

30 / 50

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

uniqueness

inheritance

completeness

specialization

31 / 50

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

Physical data independence.

Logical data independence.

Functional dependency

Concurrency control.

32 / 50

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

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.

enforces that the column will only accept null values.

33 / 50

User rights information is stored in

Logical database

Physical database

Buffer

Catalog

34 / 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.

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.

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

35 / 50

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

Full functional dependency

Any kind of dependency

Transitive dependency

Non-transitive dependency

36 / 50

Structural constraints of a relationship type refer to

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

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.

identifying the owner entity type relevant to a given entity type

37 / 50

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

software

computer infrastructure

input and output

hardware

38 / 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.

39 / 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

enforce domain integrity

enforces the uniqueness of the values in a set of columns

40 / 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.

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

41 / 50

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

Ternary

1:M

M:M

1:01

42 / 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 -> DeptNo holds over R.

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

43 / 50

Which of the following constraints enforces entity integrity?

CHECK

PRIMARY KEY

NOT NULL

FOREIGN KEY

44 / 50

Controlling redundancy in a database management system DOES NOT help to

avoid duplication

avoid unauthorised access to data

avoid unnecessary wastage of storage space

avoid inconsistency among data

45 / 50

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

► 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)

one process (which represents the entire system)

46 / 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 and B.

Only A.

47 / 50

Only B

A and B

B and C

Only A

48 / 50

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

NOT NULL

FOREIGN KEY

CHECK

UNIQUE

49 / 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.

50 / 50

User rights information is stored in

Physical database

Catalog

Buffer

Logical database

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