CS403 Midterm Online Quiz

2 votes, 5 avg

CS403-Midterm

1 / 50

statement among the following on the above diagram.

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

The diagram depicts existence dependencies.

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

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

2 / 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

any user to access all its data.

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

3 / 50

Which of the following constraints enforces entity integrity?

PRIMARY KEY

CHECK

NOT NULL

FOREIGN KEY

4 / 50

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

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

The domain of attribute must include only atomic values.

Every non-key attribute is partially dependent on super key

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

5 / 50

Which of the following is not a benefit of normalization?

Maximize redundancy

Minimize deletion anomolies

Minimize insertion anomolies

Minimize updation anomolies

6 / 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

7 / 50

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

hardware

software

input and output

computer infrastructure

8 / 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 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

9 / 50

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

inheritance

uniqueness

completeness

specialization

10 / 50

Identify the correct statement.

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.

Entity integrity constraints are specified on individual relations.

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

11 / 50

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

completeness

specialization

uniqueness

inheritance

12 / 50

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

A ternary relationship

A binary relationship

A recursive relationship

An identifying relationship

13 / 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

enforces that the column will only accept null values.

unique identifier for a row within a database table.

14 / 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

15 / 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.

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

all tuples in a particular relation may have different attributes.

all tuples in a relation must be distinct.

16 / 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

B and C

Only A

A and B

17 / 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

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

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

18 / 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 BCNF.

The relation Interview is in 3NF

The FD2 violates 2NF.

The FD3 violates 3NF.

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

The functional dependency ProjNo -> DeptNo holds over R.

20 / 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.

21 / 50

Controlling redundancy in a database management system DOES NOT help to

avoid unauthorised access to data

avoid unnecessary wastage of storage space

avoid inconsistency among data

avoid duplication

22 / 50

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

Non-transitive dependency

Transitive dependency

Any kind of dependency

Full functional dependency

23 / 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.

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.

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

24 / 50

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

Recovery service

User accessible catalog

Data processing

Authorization service

25 / 50

Which of the following is true about relational schema?

Values are atomic.

The sequence of columns is significant

Contains only derived attributes.

The sequence of rows is significant.

26 / 50

The ER- data model is an example of:

Physical database

Conceptual database

Relational database

Logical database

27 / 50

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

CHECK

UNIQUE

FOREIGN KEY

NOT NULL

28 / 50

Select the correct statement among the following.

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.

Cardinality ratios for binary relationship are displayed on Entity Relationship Diagrams by using a diamond shape notation

When different entity types participate only once in a single relationship type it is called a recursive relationship

29 / 50

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

Data

Database

DBMS

Data model

30 / 50

Which of the following is true for the relational model?

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.

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

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

31 / 50

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

DBMS

Database

Data model

Data

32 / 50

User rights information is stored in

Catalog

Physical database

Logical database

Buffer

33 / 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.

34 / 50

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

primary key

determinant

foreign key

index

35 / 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.

36 / 50

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

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

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

one process (which represents the entire system)

all sources/sinks (external entities)

37 / 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.

38 / 50

Which of the following constraints enforces entity integrity?

PRIMARY KEY

NOT NULL

CHECK

FOREIGN KEY

39 / 50

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

binary

ternary

unary

weak

40 / 50

Select the correct statement about the ANSI/SPARC architecture.

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.

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

41 / 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 and B.

Only C.

Only B and C.

Only A.

42 / 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 each table into three

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

43 / 50

A software package designed to store and manage databases

DBMS

Data

Database

Data model

44 / 50

Which of the following is true about NOT NULL constraint?

limit the values that can be placed in a column

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

45 / 50

Identify the correct way to implement one-to-one relationship in 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.·

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

by creating two separate tables

46 / 50

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

Establishing standards and procedures for database systems

Planning, designing and implementing database systems

Communicating with database users

Allocation of storage locations and data structures

47 / 50

Which of the following is not true about relational tables?

The sequence of rows is significant.

Each row is unique.

Column values are of the same kind.

Each column must have a unique name.

48 / 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.

49 / 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 DeptNo -> ProjNo holds over R.

50 / 50

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

End User

Database Administrator

Database Designer

Application Programmer

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