CS403 Midterm Online Quiz

2 votes, 5 avg

CS403-Midterm

1 / 50

Which of the following statements is NOT correct?

The functional dependency EmpNo -> DeptNo holds over R.

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

The functional dependency DeptNo -> ProjNo holds over R.

The functional dependency ProjNo -> DeptNo holds over R.

2 / 50

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

An identifying relationship

A binary relationship

A ternary relationship

A recursive relationship

3 / 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.

4 / 50

Identify the correct statement.

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.

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

5 / 50

Which of the following is not true about relational tables?

Each row is unique.

The sequence of rows is significant.

Each column must have a unique name.

Column values are of the same kind.

6 / 50

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

Any kind of dependency

Transitive dependency

Non-transitive dependency

Full functional dependency

7 / 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 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

8 / 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.

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

9 / 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.

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.

10 / 50

A software package designed to store and manage databases

Database

Data

DBMS

Data model

11 / 50

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

Functional dependency

Concurrency control.

Physical data independence.

Logical data independence.

12 / 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 relation Interview is in BCNF.

The FD2 violates 2NF.

13 / 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 ProjNo -> DeptNo holds over R.

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

14 / 50

Which of the following statements is NOT correct?

The functional dependency EmpNo -> DeptNo holds over R.

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

The functional dependency ProjNo -> DeptNo holds over R.

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

15 / 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.

16 / 50

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

Application Programmer

End User

Database Administrator

Database Designer

17 / 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.

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

Normalization is a formal technique that can be used only at the starting phase of the database design.

Normalization can be used as a top-down standalone database design technique.

18 / 50

User rights information is stored in

Physical database

Buffer

Logical database

Catalog

19 / 50

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

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.

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.

20 / 50

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

Allocation of storage locations and data structures

Planning, designing and implementing database systems

Communicating with database users

Establishing standards and procedures for database systems

21 / 50

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

CHECK

NOT NULL

FOREIGN KEY

UNIQUE

22 / 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.

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 splitting each table into three

23 / 50

A collection of related data is

Database

Relational model

Data

Logical model

24 / 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)

25 / 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.

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

all tuples in a relation must be distinct.

for any two tuples, the values associated with all ofheirt attributes may be the same.

26 / 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

27 / 50

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

completeness

inheritance

specialization

uniqueness

28 / 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 A.

Only A and B.

Only B and C.

Only C.

29 / 50

Which of the following constraints enforces entity integrity?

FOREIGN KEY

PRIMARY KEY

NOT NULL

CHECK

30 / 50

Which of the following is not a benefit of normalization?

Maximize redundancy

Minimize deletion anomolies

Minimize updation anomolies

Minimize insertion anomolies

31 / 50

Identify the correct statement.

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

Entity integrity constraints are specified on individual relations.

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.

32 / 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.

33 / 50

Only A

A and B

B and C

Only B

34 / 50

Identify the INCORRECT statement among the given

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 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.

35 / 50

Which of the following is true about relational schema?

The sequence of columns is significant

Values are atomic.

The sequence of rows is significant.

Contains only derived attributes.

36 / 50

A database system allows the following EXCEPT

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.

integration of data across multiple applications into a single application

37 / 50

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

DBMS

Data

Database

Data model

38 / 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

39 / 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 relationship type Y is of cardinality ratio 1 : N.

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

40 / 50

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

Data

Data model

DBMS

Database

41 / 50

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

Ternary

M:M

1:01

1:M

42 / 50

Select the correct statement about the ANSI/SPARC architecture.

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

The internal level in a database system will definitely be relational.

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

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

Every non-key attribute is partially dependent on super key

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

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

The domain of attribute must include only atomic values.

44 / 50

Which of the following is true for the relational model?

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

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.

45 / 50

The ER- data model is an example of:

Relational database

Logical database

Conceptual database

Physical database

46 / 50

Which of the following constraints enforces entity integrity?

CHECK

NOT NULL

FOREIGN KEY

PRIMARY KEY

47 / 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

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.

48 / 50

Which of the following is true about NOT NULL constraint?

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

enforce domain integrity

49 / 50

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

ternary

unary

binary

weak

50 / 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.

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