Sample Copy. Not For Distribution.UNIT III TRANSACTION PROCESSING AND CONCURRENCY CONTROL 115...

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Exam Made Easy


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iii

Exam Made Easy Database Management Systems

(AS PER NEW SYLLABUS OF UNIVERSITY)

By

Dr. V. Rajeswari, Ph.D.

Ms. M. Kavitha, MCA.,M.Phil

EDUCREATION PUBLISHING (Since 2011)

www.educreation.in


iv

PREFACE

The Technical education in India is changing rapidly in the emerging fields to meet future

challenges. Newer areas like BigData and DataScience have become extended database

subjects. In this process, UNIVERSITY has revised the syllabus for B.E/ B.Tech, B.Sc

(Computer Science), BCS, MCA to incorporate the latest developments in technology.

In view of this, the book covers the latest revised syllabus of UNIVERSITY for the

subject “DATABASE MANAGEMENT SYSTEMS” for the B.E / B.Tech students/BCA,

B.Sc (Computer Science)/MCA.

The book “UNIVERSITY Q & A for DATABASE MANAGEMENT SYSTEMS”

has been compiled for students studying at undergraduate level and covers almost all

topics required to enhance the knowledge in Database Management Systems. The book is

organized in a way to help beginners in understanding the database concepts better.

This book owes its existence to the collaboration made possible by the Internet and

the free software movements.

Salient features of this book:

This book provides 500 + multiple choice questions on Database Management

Systems, separated into 30 categories. The questions have been used in examinations

for undergraduate introductory courses and as such reflect the focus of these

particular courses and are pitched at the level to challenge students that are beginning

their training in Database Management Systems.

This book provides 200+ Two Marks Questions and Answers, 100+ Sixteen Mark

Questions and Previous year Question Papers.

The Questions are competent and handy for those who appear for the University

Exams, Certification Exams, Competitive Exams and Entrance Exams.

The questions and answer combinations are to be used both by teachers, to select

questions for their next examinations, and by students, when studying for an

upcoming test.

While preparing the book immense care has been taken to help students who are

preparing for the technical rounds to win competitions.

We wanted the questions to cover a wide range of topics, so that this book would

provide a comprehensive approach for the students

In recent years, the evolution of internet and communication technologies and the

proliferation of product alternatives have led to a more dynamic but also more

complex search and decision process for consumers. We thank the communication

technologies for these path-breaking tools that enable access to vast knowledge base.

We welcome your suggestions for improvement and those will be gratefully

acknowledged.

Dr. V. Rajeswari

Ms. M. Kavitha


v

SYLLABUS DATABASE MANAGEMENT SYSTEMS

S. No. Content Page

1. UNIT I INTRODUCTION TO DBMS 1

File Systems Organization - Sequential, Pointer, Indexed, Direct

- Purpose of Database System- Database System Terminologies-

Database characteristics- Data models – Types of data models –

Components of DBMS- Relational Algebra. LOGICAL

DATABASE DESIGN: Relational DBMS - Codd's Rule -

Entity-Relationship model - Extended ER Normalization –

Functional Dependencies, Anomaly- 1NF to 5NF- Domain Key

Normal Form – Denormalization

2. UNIT II SQL & QUERY OPTIMIZATION 33

SQL Standards - Data types - Database Objects- DDL-DML-

DCL-TCL-Embedded SQL-Static Vs Dynamic SQL - QUERY

OPTIMIZATION: Query Processing and Optimization -

Heuristics and Cost Estimates in Query Optimization.

3. UNIT III TRANSACTION PROCESSING AND

CONCURRENCY CONTROL

115

Introduction-Properties of Transaction- Serializability-

Concurrency Control – Locking Mechanisms- Two Phase

Commit Protocol-Dead lock.

4. UNIT IV TRENDS IN DATABASE TECHNOLOGY 132

Overview of Physical Storage Media – Magnetic Disks – RAID

– Tertiary storage – File Organization – Organization of Records

in Files – Indexing and Hashing –Ordered Indices – B+ tree

Index Files – B tree Index Files – Static Hashing – Dynamic

Hashing - Introduction to Distributed Databases- Client server

technology- Multidimensional and Parallel databases- Spatial

and multimedia databases-Mobile and web databases- Data

Warehouse-Mining- Data marts.

5. UNIT V ADVANCED TOPICS 167

DATABASE SECURITY: Data Classification-Threats and risks

– Database access Control – Types of Privileges –Cryptography-

Statistical Databases.- Distributed Databases-Architecture-


vi

Transaction Processing-Data Warehousing and Mining-

Classification-Association rules-Clustering-Information

Retrieval- Relevance ranking-Crawling and Indexing the Web-

Object Oriented Databases-XML Databases.


Database Management Systems

1 | Exam Made Easy

UNIT - I

Multiple Choice Questions and Answers

Two Mark Questions and Answers

Sixteen Mark Questions



2 | Exam Made Easy

UNIT – 1 - Multiple Choice Questions and Answers

Q. No: 1

____________ is software to store, organize and retrieve data from database.

A) Data dictionary

B) Database management system (DBMS)

C) Decision support system

D) Relational Database

Answer: B

Q. No: 2

The database report writer __________.

A) is a career path that focuses on creating, managing and supporting the reports

generated from databases

B) Provide limited control over how information is displayed and reported.

C) Provides the tools for database designer to display information in the desired format

D) Provides the tools for the database admin monitor and report on database use and

activity

Answer: C

Q. No: 3

_________ is the power to change the physical data without impacting the schema or

logical data.

A) Data dictionary

B) Physical Data independence

C) Data integrity

D) Referential integrity

Answer: B

Q. No: 4

The database in client/server model __________.

A) is downloaded to the client upon request

B) is shared by both the client and server

C) resides on the client side

D) resides on the server side

Answer: D

Q. No: 5

__________ model stores data in separate folders in filing cabinets.

A) Hierarchical

B) Network

C) Object oriented

D) Relational



3 | Exam Made Easy

Answer: A

Q. No: 6

__________ stores data in the form of tables which are linked together through matching

process.

A) Hierarchical database

B) Network database

C) Object oriented database

D) Relational Database

Answer: D

Q. No: 7

The main limitation of Hierarchical Database is __________.

A) Limited capacity (unable to hold much data)

B) Limited flexibility in accessing data

C) Overhead associated with maintaining indexes

D) The performance of the database is poor

Answer: B

Q. No: 8

What is the use of Abstract data type?

A) link data from remote databases

B) prevent users from getting to database security Information

C) provide a conceptual view of the data so it is easier to Understand

D)store complex data structure to represent the properties of objects

Answer: D

Q. No: 9

___________ is the phase which involves critical areas, expensive hardware or software

within the organization.

A) Analysis phase

B) Feasibility study

C) Investigation stage

D) System design

Answer: B

Q. No: 10

Which component of the database management system (DBMS) affects the ability to

handle large problems (scalability)?

A) Data Storage Subsystem

B) Database Engine

C) Query Processor

D) Security subsystem

Answer: B



4 | Exam Made Easy

Q. No: 11

The primary difference between the Relational databases (RDB) and Object Oriented

database (OODB) models are ______________.

A) OODB incorporates methods in with the definition of the data structure, while RDB

does not

B) OODB supports multiple objects in the same database while RDB only supports a

single table per database

C) RDB allows the definition of the relationships Between the different tables, while

OODB does not allow the relationships to be defined between objects

D) RDB supports indexes, while OODB does not support indexes

Answer: A

Q. No: 12

is/are advantages of database management system.

A) Improved ability to enforce standards

B) Improved data consistency

C) Local control over the data

D) Minimal data redundancy

Answer: A, B, C

Q. No: 13

The predominant way of storing data today is using .

A) Hierarchical

B) Network

C) Object oriented

D) Relational

Answer: D

Q. No: 14

Characteristics of entity are described by .

A) Classes

B) Entities

C) Properties

D) Traits

Answer: C

Q. No: 15

The data dealing with an entity is termed as .

A) Attribute

B) Class

C) Object

D) Table

Answer: B

Q. No: 16

Database system modelers use to graphically represent both the data

structure and how the Different objects are interrelated.

A) Class Diagram

B) Data Diagram



5 | Exam Made Easy

C) Object Diagram

D) Table Relationship Diagram

Answer: A

Q. No: 17

In relational database model the information contained in a single class would be stored

in a _________ .

A) Database

B) Field

C) Property

D) Table

Answer: D

Q. No: 18

_________ is used to retrieve unique record from a table.

A) Identifier

B) Index

C) Primary Key

D) Symmetric Key

Answer: C

Q. No: 19

____________ represents the business rules of database.

A) Associations (or relationships)

B) Attributes

C) Properties

D) Secondary keys

Answer: A

Q. No: 20

The Association rule defines __________.

A) How frequently the items appear in the database.

B) The relationship between the class diagram and the Tables in the database

C) The tables that each attribute is contained

D) Which attribute is the table's primary key

Answer: A

Q. No: 21

__________ is the purpose of an N-Ary association.

A) Capture a parent-child relationship

B) Deal with one to many relationships

C) Relationships with more than two tables

D) None of the above

Answer: C

Q. No: 22

A Composition association depicted in ER by __________.

A) A line which loops back onto the same table

B) Small closed diamond at the end of a line connecting two tables



6 | Exam Made Easy

C) Small open diamond at the end of a line connecting two tables

D) Small triangle at the end of a line connecting the aggregated item and multiple

component items

Answer: B

Q. No: 23

A Reflexive association is represented by ____________.

A) A line which loops back onto the same table

B) Small closed diamond at the end of a line connecting two tables

C) Small open diamond at the end of a line connecting two tables

D) Small triangle at the end of a line connecting the aggregated item and multiple

component items

Answer: A

Q. No: 24

What is the most appropriate special association to model that a class may have multiple

pre-requisites while creating a database for the college?

A) Aggregation association

B) Generalization association

C) N-ary association

D) Reflexive association

Answer: D

Q. No: 25

What is the most appropriate special association to model degree requirements (i.e.,

required number of courses in Humanity, science, math, etc) while creating a database

for the college?

A) Composition association




Answer: A

Q. No: 26

What is the most appropriate special association to model that a course has an assigned

instructor, Teaching Assistants, a classroom, meeting time slot, and class roster while

creating a database for the college?





Answer: C

Q. No: 27

__________ is the most appropriate special association that indicates that multiple

textbooks make up a course required reading list.




7 | Exam Made Easy




Answer: C

Q. No: 28

_________ specifies an object with common properties that can be used at lower levels

with specialized properties.

A) Composition association




Answer: B

Q. No: 29

__________ is the ability to define common properties or functions in the higher class

and then modify them in the lower classes.

A) Inheritance

B) Polymorphism

C) Reflexive

D) Transformance

Answer: B

Q. No: 30

In a reflexive association one class is_________ .

A) Broken down into special cases

B) Combined with multiple other classes

C) Combined with one other class

D) Linked back to itself

Answer: D

Q. No: 31

Choose the incorrect statement from the following.

A) A primary goal of a database system is to share data with multiple users

B) It is possible to change a method or property inherited from a higher level class

C) While companies collect data all the time, the structure of the data changes very often.

D) In a client / server environment, data independence causes client side applications to

be essentially independent of the database stored on the server side.

Answer: C

Q. No: 32


A) Data Normalization is the process of defining the table structure

B) The purpose of class diagrams is to model the interrelationships between the different

classes in the database

C) Individual objects are stored as rows in a table

D) Properties of an object are stored as columns in a table.

Answer: A



8 | Exam Made Easy

Q. No: 33


A) The primary key must be unique for a given table

B) Specifying a zero (0) for the lower bound for the association multiplicity on a class

diagram indicates that the item is required

C) Specifying a one (1) for the lower bound for the association multiplicity on a class

diagram indicates that the item is required

D) Most databases allow multiple records that are identical (i.e., records that have the

same values for all properties).

Answer: B

Q. No: 34


A) All many-to-many relationships must be converted to a set of one-to-many

relationships by adding a new entity

B) In a one-to-one relationship between two classes, the two classes are generally

described by one table in relational database model

C) Encapsulation provides some security and control features

D) Properties and functions can be protected from other areas of the applications

Answer: B

Q. No: 35

___________ is a very small unit of a program and it may contain several lowlevel tasks.

A) Transaction

B) Commit

C) Rollback

D) Flashback

Answer: A

Q. No: 36

_________ saves the data permanently in database.

A) View

B) Commit

C) Rollback

D) Flashback

Answer: B

Q. No: 37

Consider the following

Savepoint s1…

Transaction 1..

savepoint s2…

Transaction 2..

Commit..

save point s3..

Transaction 3..

Rollback to s1

What does Rollback do?



9 | Exam Made Easy

A) Undoes all Transaction after savepoint 1

B) No such savepoint – Error.

C) Undoes upto savepoint s3

D) No Action.

Answer: B

Q. No: 38

Consider the following

Transaction 1…

Commit;

Transaction 2..

Rollback;

What does Rollback do?

A) Undoes both Transactions 1 and 2

B) Undoes Transaction 2 alone.

C) Clears all transaction from the beginning of the session

D) No Action.

Answer: B

Q. No: 39

_________ statement is executed automatically when a transaction ends before commit.

A) View

B) Commit

C) Rollback

D) Flashback

Answer: C

Q. No: 40

Consistency in database is maintained through __________ operation.

A) Commit

B) Atomic

C) Flashback

D) Retain

Answer: B

Q. No: 41

Transaction processing is associated with ___________.

A) Conforming a action or triggering a response

B) Producing detail summary or exception report

C) Recording a business activity

D) Maintaining a data

Answer: B,C,D

Q. No: 42

A transaction is said to be complete only when it is ___________.

A) Committed

B) Aborted

C) Rolled back


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