CS403 Midterm Online Quiz

2 votes, 5 avg

CS403-Midterm

1 / 50

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

inheritance

completeness

uniqueness

specialization

2 / 50

Which of the following statements is NOT correct?

The functional dependency DeptNo -> ProjNo holds over R.

The functional dependency ProjNo -> DeptNo holds over R.

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

The functional dependency EmpNo -> DeptNo holds over R.

3 / 50

Which of the following constraints enforces entity integrity?

CHECK

FOREIGN KEY

NOT NULL

PRIMARY KEY

4 / 50

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

CHECK

UNIQUE

FOREIGN KEY

NOT NULL

5 / 50

User rights information is stored in

Catalog

Buffer

Logical database

Physical database

6 / 50

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

by splitting each table into three

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.

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

7 / 50

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

by splitting each table into three

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 the data into two tables with primary key and foreign key relationships

8 / 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 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.

9 / 50

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

inheritance

specialization

completeness

uniqueness

10 / 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.

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.

11 / 50

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

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.

Every non-key attribute is partially dependent on super key

12 / 50

Which of the following is correct?

The relation Interview is in BCNF.

The FD2 violates 2NF.

The relation Interview is in 3NF

The FD3 violates 3NF.

13 / 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.

14 / 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)

15 / 50

Which of the following statements is NOT correct?

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

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.

16 / 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

17 / 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.

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.

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

18 / 50

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

Any kind of dependency

Non-transitive dependency

Full functional dependency

Transitive dependency

19 / 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.

20 / 50

Which of the following constraints enforces entity integrity?

FOREIGN KEY

NOT NULL

PRIMARY KEY

CHECK

21 / 50

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

A binary relationship

A recursive relationship

An identifying relationship

A ternary relationship

22 / 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)

23 / 50

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

Recovery service

Authorization service

Data processing

User accessible catalog

24 / 50

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

Data

DBMS

Data model

Database

25 / 50

The ER- data model is an example of:

Relational database

Conceptual database

Logical database

Physical database

26 / 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.

27 / 50

statement among the following on the above diagram.

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

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

The diagram depicts existence dependencies.

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

28 / 50

Which of the following is not a benefit of normalization?

Minimize insertion anomolies

Minimize updation anomolies

Maximize redundancy

Minimize deletion anomolies

29 / 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.

all tuples in a particular relation may have different attributes.

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

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

30 / 50

Structural constraints of a relationship type refer to

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 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.

31 / 50

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

computer infrastructure

hardware

software

input and output

32 / 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.

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

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

33 / 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

34 / 50

Which of the following is true about relational schema?

Values are atomic.

The sequence of columns is significant

The sequence of rows is significant.

Contains only derived attributes.

35 / 50

Identify the INCORRECT statement among the given

An entity may be an object with a physical existence like a car, a house or an Employee.

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.

One cannot consider something which has conceptual existence like a course in a degree program as an entity.

36 / 50

A collection of related data is

Database

Relational model

Logical model

Data

37 / 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.

38 / 50

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

weak

binary

unary

ternary

39 / 50

Structural constraints of a relationship type refer to

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.

whether the existence of an entity depends on it being related to another entity via the relationship type.

40 / 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

Only B

A and B

Only A

41 / 50

User rights information is stored in

Logical database

Buffer

Catalog

Physical database

42 / 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.

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

integration of data across multiple applications into a single application

any user to access all its data.

43 / 50

Which of the following is true about NOT NULL constraint?

enforce domain integrity

prevents any actions that would destroy links between tables with the corresponding data values

limit the values that can be placed in a column

enforces the uniqueness of the values in a set of columns

44 / 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

45 / 50

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

Database

Data model

Data

DBMS

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 C.

Only A and B.

Only A.

Only B and C.

47 / 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

48 / 50

The ER- data model is an example of:

Physical database

Relational database

Conceptual database

Logical database

49 / 50

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

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

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

50 / 50

A software package designed to store and manage databases

DBMS

Data

Data model

Database

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