CS403 Midterm Online Quiz

2 votes, 5 avg

CS403-Midterm

1 / 50

Identify the correct statement.

Entity integrity constraints are specified between weak entities.

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.

2 / 50

Which of the following statements is NOT correct?

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

The functional dependency ProjNo -> DeptNo holds over R.

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

The functional dependency EmpNo -> DeptNo holds over R.

3 / 50

User rights information is stored in

Buffer

Physical database

Logical database

Catalog

4 / 50

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

all sources/sinks (external entities)

one process (which represents the entire system)

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

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

5 / 50

Which of the following is not a benefit of normalization?

Minimize updation anomolies

Maximize redundancy

Minimize deletion anomolies

Minimize insertion anomolies

6 / 50

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

input and output

hardware

software

computer infrastructure

7 / 50

The ER- data model is an example of:

Logical database

Relational database

Physical database

Conceptual database

8 / 50

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

End User

Database Administrator

Database Designer

Application Programmer

9 / 50

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

specialization

completeness

inheritance

uniqueness

10 / 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.

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

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

11 / 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

12 / 50

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

NOT NULL

FOREIGN KEY

UNIQUE

CHECK

13 / 50

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

ternary

unary

binary

weak

14 / 50

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

Data

Database

DBMS

Data model

15 / 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

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

any user to access all its data.

16 / 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 the data into two tables with primary key and foreign key relationships.

by splitting each table into three

17 / 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.

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.

Normalization can be used as a top-down standalone database design technique.

18 / 50

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

specialization

uniqueness

completeness

inheritance

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 ProjNo -> DeptNo holds over R.

The functional dependency DeptNo -> ProjNo holds over R.

20 / 50

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

Database

Data model

DBMS

Data

21 / 50

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

Non-transitive dependency

Any kind of dependency

Transitive dependency

Full functional dependency

22 / 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 3NF

The FD3 violates 3NF.

The FD2 violates 2NF.

The relation Interview is in BCNF.

23 / 50

User rights information is stored in

Buffer

Catalog

Physical database

Logical database

24 / 50

Which of the following is true about relational schema?

Contains only derived attributes.

The sequence of rows is significant.

The sequence of columns is significant

Values are atomic.

25 / 50

A software package designed to store and manage databases

Data

Database

Data model

DBMS

26 / 50

Which of the following statements is NOT correct?

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.

The functional dependency EmpNo -> DeptNo holds over R.

27 / 50

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

primary key

determinant

index

foreign key

28 / 50

Which of the following is not true about relational tables?

Each row is unique.

The sequence of rows is significant.

Column values are of the same kind.

Each column must have a unique name.

29 / 50

Select the correct statement among the following.

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

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.

30 / 50

Which of the following is correct?

The relation Interview is in BCNF.

The FD2 violates 2NF.

The FD3 violates 3NF.

The relation Interview is in 3NF

31 / 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.

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.

all tuples in a particular relation may have different attributes.

32 / 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

33 / 50

Structural constraints of a relationship type refer to

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.

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.

34 / 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.

A and B

B and C

Only B

Only A

35 / 50

B and C

A and B

Only A

Only B

36 / 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.

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

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

37 / 50

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

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.

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.

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

38 / 50

statement among the following on the above diagram.

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

The diagram depicts existence dependencies.

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

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

39 / 50

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

A ternary relationship

An identifying relationship

A recursive relationship

A binary relationship

40 / 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.

allow any actions that would destroy links between tables

limit the values that can be placed in a column.

41 / 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.

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

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.

42 / 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

43 / 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.

44 / 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 B and C.

Only C.

Only A.

Only A and B.

45 / 50

Which of the following constraints enforces entity integrity?

CHECK

FOREIGN KEY

PRIMARY KEY

NOT NULL

46 / 50

Which of the following constraints enforces entity integrity?

NOT NULL

CHECK

FOREIGN KEY

PRIMARY KEY

47 / 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.

48 / 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.

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

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

49 / 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

50 / 50

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

Communicating with database users

Establishing standards and procedures for database systems

Planning, designing and implementing database systems

Allocation of storage locations and data structures

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