CS403 Midterm Online Quiz

2 votes, 5 avg

CS403-Midterm

1 / 50

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

Database Administrator

Database Designer

End User

Application Programmer

2 / 50

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

determinant

foreign key

index

primary key

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

The functional dependency ProjNo -> DeptNo holds over R.

4 / 50

Which of the following is correct?

The FD3 violates 3NF.

The relation Interview is in 3NF

The FD2 violates 2NF.

The relation Interview is in BCNF.

5 / 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.

6 / 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.

7 / 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 B

Only A

8 / 50

A software package designed to store and manage databases

Database

DBMS

Data model

Data

9 / 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.

10 / 50

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

Establishing standards and procedures for database systems

Communicating with database users

Allocation of storage locations and data structures

Planning, designing and implementing database systems

11 / 50

A relation (from the relational database model) consists of a set of tuples, which implies that

all tuples in a relation must be distinct.

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.

12 / 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.

Physical data independence.

Functional dependency

13 / 50

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

input and output

software

hardware

computer infrastructure

14 / 50

Which of the following constraints enforces entity integrity?

PRIMARY KEY

FOREIGN KEY

CHECK

NOT NULL

15 / 50

Which of the following constraints enforces entity integrity?

FOREIGN KEY

PRIMARY KEY

CHECK

NOT NULL

16 / 50

The ER- data model is an example of:

Relational database

Physical database

Conceptual database

Logical database

17 / 50

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

uniqueness

completeness

specialization

inheritance

18 / 50

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

Any kind of dependency

Non-transitive dependency

Transitive dependency

Full functional dependency

19 / 50

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

Instructor – Student

Student – Instructor

Instructor ÷ Student

Student ∩ Instructor

20 / 50

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

binary

weak

unary

ternary

21 / 50

Which of the following is not true about relational tables?

The sequence of rows is significant.

Each column must have a unique name.

Column values are of the same kind.

Each row is unique.

22 / 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.

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

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

23 / 50

Identify the correct statement.

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

Entity integrity constraints are specified between weak entities.

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.

24 / 50

Select the correct statement among the following.

Role names are not technically necessary in relationship types when all the participating entity types are distinct.

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

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

25 / 50

User rights information is stored in

Buffer

Logical database

Physical database

Catalog

26 / 50

The ER- data model is an example of:

Physical database

Conceptual database

Logical database

Relational database

27 / 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.

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

28 / 50

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

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.

unique identifier for a row within a database table.

29 / 50

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

User accessible catalog

Data processing

Recovery service

Authorization service

30 / 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.

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

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

31 / 50

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

Every non-key attribute is partially dependent on super key

The domain of attribute must include only atomic values.

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

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

32 / 50

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

completeness

uniqueness

inheritance

specialization

33 / 50

Controlling redundancy in a database management system DOES NOT help to

avoid unnecessary wastage of storage space

avoid unauthorised access to data

avoid duplication

avoid inconsistency among data

34 / 50

Identify the correct statement.

Entity integrity constraints are specified between weak entities.

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 specify that primary key values can be composite.

35 / 50

Which of the following is not a benefit of normalization?

Maximize redundancy

Minimize updation anomolies

Minimize insertion anomolies

Minimize deletion anomolies

36 / 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

37 / 50

Structural constraints of a relationship type refer to

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.

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.

38 / 50

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

NOT NULL

FOREIGN KEY

UNIQUE

CHECK

39 / 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.

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

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

by creating two separate tables

40 / 50

Identify the correct statement with respect to normalization.

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.

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.

41 / 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.

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.

42 / 50

Which of the following is true about relational schema?

The sequence of columns is significant

The sequence of rows is significant.

Contains only derived attributes.

Values are atomic.

43 / 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.

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.

44 / 50

Which of the following is true about relational schema?

Values are atomic.

Contains only derived attributes.

The sequence of columns is significant

The sequence of rows is significant.

45 / 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

46 / 50

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

Data

Database

Data model

DBMS

47 / 50

Only B

A and B

B and C

Only A

48 / 50

Which of the following constraints enforces entity integrity?

NOT NULL

CHECK

FOREIGN KEY

PRIMARY KEY

49 / 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)

50 / 50

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

Data

Data model

Database

DBMS

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