CS403 Midterm Online Quiz

2 votes, 5 avg

CS403-Midterm

1 / 50

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

Data

Database

DBMS

Data model

2 / 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.

3 / 50

Which of the following statements is NOT correct?

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

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.

4 / 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 creating two separate 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.

5 / 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.

6 / 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.

7 / 50

Which of the following is not true about relational tables?

The sequence of rows is significant.

Column values are of the same kind.

Each column must have a unique name.

Each row is unique.

8 / 50

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

Concurrency control.

Logical data independence.

Functional dependency

Physical data independence.

9 / 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)

one process (which represents the entire system)

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

10 / 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

Only B

A and B

B and C

11 / 50

Which of the following constraints enforces entity integrity?

CHECK

FOREIGN KEY

NOT NULL

PRIMARY KEY

12 / 50

Which of the following is not a benefit of normalization?

Minimize updation anomolies

Minimize deletion anomolies

Maximize redundancy

Minimize insertion anomolies

13 / 50

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

uniqueness

completeness

inheritance

specialization

14 / 50

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

input and output

software

hardware

computer infrastructure

15 / 50

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

1:01

1:M

Ternary

M:M

16 / 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 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 internal level in a database system will definitely be relational.

17 / 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.

any user to access all its data.

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.

18 / 50

The ER- data model is an example of:

Logical database

Conceptual database

Relational database

Physical database

19 / 50

User rights information is stored in

Physical database

Catalog

Buffer

Logical database

20 / 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 B and C.

Only A.

Only C.

21 / 50

Only B

B and C

A and B

Only A

22 / 50

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

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

The domain of attribute must include only atomic values.

Every non-key attribute is partially dependent on super key

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

23 / 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

24 / 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) -> ProjNo holds over R.

The functional dependency EmpNo -> DeptNo holds over R.

25 / 50

The ER- data model is an example of:

Conceptual database

Physical database

Logical database

Relational database

26 / 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.

Nullvalue is a blank or zero value given to an attribute value when its value is inapplicable or its value is unknown.

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

27 / 50

Which of the following constraints enforces entity integrity?

NOT NULL

CHECK

FOREIGN KEY

PRIMARY KEY

28 / 50

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

unary

weak

binary

ternary

29 / 50

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

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.

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.

30 / 50

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

completeness

specialization

inheritance

uniqueness

31 / 50

Controlling redundancy in a database management system DOES NOT help to

avoid inconsistency among data

avoid duplication

avoid unnecessary wastage of storage space

avoid unauthorised access to data

32 / 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.

identifying the owner entity type relevant to a given entity type

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

33 / 50

statement among the following on the above diagram.

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

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

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

The diagram depicts existence dependencies.

34 / 50

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

one process (which represents the entire system)

all sources/sinks (external entities)

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

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

35 / 50

A software package designed to store and manage databases

Database

Data

Data model

DBMS

36 / 50

A collection of related data is

Relational model

Database

Logical model

Data

37 / 50

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

Data processing

Authorization service

Recovery service

User accessible catalog

38 / 50

Which of the following is true about relational schema?

Values are atomic.

The sequence of rows is significant.

The sequence of columns is significant

Contains only derived attributes.

39 / 50

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

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

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

40 / 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

enforces the uniqueness of the values in a set of columns

limit the values that can be placed in a column

enforce domain integrity

41 / 50

Which of the following is true about relational schema?

Values are atomic.

The sequence of rows is significant.

Contains only derived attributes.

The sequence of columns is significant

42 / 50

Which relational algebra operation could have been applied on the pair of relations Student and Instructor to obtain the above data?

Instructor – Student

Instructor ÷ Student

Student ∩ Instructor

Student – Instructor

43 / 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 between weak entities.

Entity integrity constraints are specified on individual relations.

44 / 50

User rights information is stored in

Buffer

Physical database

Catalog

Logical database

45 / 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.

46 / 50

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

Data

DBMS

Database

Data model

47 / 50

Which of the following is correct?

The relation Interview is in 3NF

The FD2 violates 2NF.

The relation Interview is in BCNF.

The FD3 violates 3NF.

48 / 50

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

Application Programmer

End User

Database Designer

Database Administrator

49 / 50

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

UNIQUE

CHECK

NOT NULL

FOREIGN KEY

50 / 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

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The average score is 22%