CS403 Midterm Online Quiz

2 votes, 5 avg

CS403-Midterm

1 / 50

Identify the correct statement.

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.

Referential integrity constraints check whether the primary key values are unique.

2 / 50

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

1:01

Ternary

M:M

1:M

3 / 50

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

Data model

Database

Data

DBMS

4 / 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

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

Transformation of the high level data model into the implementation data model is called logical design or data model mapping

5 / 50

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

Any kind of dependency

Transitive dependency

Non-transitive dependency

Full functional dependency

6 / 50

Which of the following is not a benefit of normalization?

Minimize deletion anomolies

Minimize insertion anomolies

Maximize redundancy

Minimize updation anomolies

7 / 50

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

Authorization service

Recovery service

Data processing

User accessible catalog

8 / 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.

Only B and C.

Only A and B.

9 / 50

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

uniqueness

specialization

inheritance

completeness

10 / 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.

Any given database has many conceptual schemas and one physical schema, but it has only one external schemas.

The external level is not concerned with individual user perceptions, while the conceptual level is concerned with a community user perception.

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

11 / 50

User rights information is stored in

Buffer

Catalog

Physical database

Logical database

12 / 50

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

FOREIGN KEY

CHECK

NOT NULL

UNIQUE

13 / 50

User rights information is stored in

Catalog

Logical database

Physical database

Buffer

14 / 50

Identify the correct statement with respect to normalization.

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 dependency reservation property at any cost whereas the lossless join property is sometimes sacrificed.

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

15 / 50

Which of the following constraints enforces entity integrity?

NOT NULL

CHECK

PRIMARY KEY

FOREIGN KEY

16 / 50

The ER- data model is an example of:

Physical database

Conceptual database

Relational database

Logical database

17 / 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.

any user to access all its data.

integration of data across multiple applications into a single application

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

18 / 50

The ER- data model is an example of:

Logical database

Conceptual database

Physical database

Relational database

19 / 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 between weak entities.

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

Entity integrity constraints are specified on individual relations.

20 / 50

A software package designed to store and manage databases

Database

Data

DBMS

Data model

21 / 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.

22 / 50

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

A recursive relationship

A ternary relationship

An identifying relationship

A binary relationship

23 / 50

Controlling redundancy in a database management system DOES NOT help to

avoid inconsistency among data

avoid unauthorised access to data

avoid unnecessary wastage of storage space

avoid duplication

24 / 50

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

ternary

binary

weak

unary

25 / 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

Student ∩ Instructor

Instructor ÷ Student

26 / 50

Select the correct statement among the following.

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

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

27 / 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.

28 / 50

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

Database

Data model

Data

DBMS

29 / 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.

30 / 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)

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

one process (which represents the entire system)

31 / 50

Which of the following is true about relational schema?

The sequence of rows is significant.

The sequence of columns is significant

Contains only derived attributes.

Values are atomic.

32 / 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 on individual relations.

Entity integrity constraints are specified between weak entities.

33 / 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.

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.·

34 / 50

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

uniqueness

specialization

completeness

inheritance

35 / 50

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

primary key

index

determinant

foreign key

36 / 50

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

unique identifier for a row within a database table.

enforces that the column will only accept null values.

limit the values that can be placed in a column.

allow any actions that would destroy links between tables

37 / 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

38 / 50

Identify the INCORRECT statement among the given

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.

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

39 / 50

Which of the following is correct?

The FD2 violates 2NF.

The relation Interview is in BCNF.

The relation Interview is in 3NF

The FD3 violates 3NF.

40 / 50

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

Database Administrator

End User

Database Designer

Application Programmer

41 / 50

Which of the following constraints enforces entity integrity?

PRIMARY KEY

NOT NULL

CHECK

FOREIGN KEY

42 / 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

enforce domain integrity

enforces the uniqueness of the values in a set of columns

43 / 50

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

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

by splitting each table into three

44 / 50

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

one process (which represents the entire system)

all sources/sinks (external entities)

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

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

45 / 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.

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.

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.

46 / 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

47 / 50

Which of the following is true about relational schema?

Contains only derived attributes.

Values are atomic.

The sequence of rows is significant.

The sequence of columns is significant

48 / 50

Which of the following statements is NOT correct?

The functional dependency EmpNo -> DeptNo holds over R.

The functional dependency DeptNo -> ProjNo holds over R.

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

The functional dependency ProjNo -> DeptNo holds over R.

49 / 50

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

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.

all tuples in a particular relation may have different attributes.

50 / 50

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

Communicating with database users

Planning, designing and implementing database systems

Allocation of storage locations and data structures

Establishing standards and procedures for database systems

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