This document provides an overview of database management systems (DBMS). It discusses the objectives and features of DBMS, including organizing data in a structured way and storing data only once. Common applications of DBMS are also outlined, such as enterprise information systems, banking, universities, and telecommunications. The document then examines the purpose of using a DBMS to share and secure data. Key concepts like data models, database languages, and the relational database model are introduced at a high level.

1. SESSION NO - I
DBMS
By Dr. Dhobale J V
Assistant Professor
IBS, IFHE, Hyderabad.
IBS Hyderabad 1

2. Objectives
 Database System Applications.
 Purpose of Database systems.
 View of Data.
 Database Language.
 Relational Database.
 Database Design.
 Database Architecture.
 Database Users and DBA.
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3. DBMS
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4. DBMS
 DBMS (Database Management Systems)?
 Is a collection of interrelated data and a set of
programs to access those data.
 The collection of data, usually referred to as
database, contains information relevant to an
enterprise.
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5. DBMS
 Database systems are designed to manage
large bodies of information.
 Management of data involves both defining
structures for storage of information and
providing mechanism for the manipulation of
information.
 Ensures safety of information.
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6. Data and Information
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7. Data and Information
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8. DBMS features
1. It is well organized.
2. It is related.
3. It is accessible in different orders without
great difficulty.
4. It is stored only once.
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9. DBMS Applications
 Databases are widely used –
1. Enterprise Information –
 Sales – Customer, Product & Purchase information.
 Accounting – Payments, Receipts, account
balances, assets and other accounting information.
 HR – Employees information, salaries, payroll taxes
& benefits.
 Manufacturing – Management of SCM, inventories
of items in warehouses & stores and ordered items.
 Online retailers – Online order tracking generation,
maintenance of online product evaluation.
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10. DBMS Applications
2. Banking and Finance –
 Banking – Customer information, account, loans,
banking transactions.
 Credit card transactions – Purchases on credit
cards and generation of monthly statements.
 Finance – information about holdings, sales, and
purchase of financial instruments such as stocks
and bonds.
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11. DBMS Applications
3. Universities – Student information, course
registrations and grades along with enterprise
information.
4. Airlines – Reservations and schedule
information.
 Firstly use DBMS capabilities in a
geographically distributed manner.
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12. DBMS Applications
5. Telecommunication – records of calls made,
Billing information, record of prepaid calling
and balances, communication network
information.
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13. Purpose of DBMS
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14. Purpose of DBMS
 Database Approach –
 Many programs and users can share data in
database.
 Secures data so that authorized users can
access certain data.
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15. Purpose of DBMS
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16. Purpose of DBMS
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17. Purpose of DBMS
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18. Views of Data - Abstraction
 We know that the same thing, if viewed from
different angles produces difference sights.
Likewise, the database that we have created
already can have different aspects to reveal if
seen from different levels of abstraction.
 Abstraction means the amount of detail you
want to hide.
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19. Views of Data – Abstraction Example
 A computer reveals the minimum of its internal
details, when seen from outside.
 We do not know what parts it is built with. This
is the highest level of abstraction.
 If we open the computer case and look inside
at the hard disc, motherboard, CD drive, CPU
and RAM, we are in middle level of
abstraction. 19IBS Hyderabad

20. Views of Data – Abstraction Example
 If we move on to open the hard disc and
examine its tracks, sectors and read-write
heads, we are at the lowest level of
abstraction.
 In the same manner, the database can also be
viewed from different levels of abstraction to
reveal different levels of details. where no
details are invisible. 20IBS Hyderabad

21. Views of Data – Abstraction Levels
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22. Views of Data – Abstraction Levels
 The word schema means arrangement (design) – how
we want to arrange things that we have to store.
 The diagram above shows the three different schemas
used in DBMS, seen from different levels of
abstraction.
 The collection of information stored in the database at
a particular moment is called an instance.
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23. Data Models
 Data Models are nothing but Rules and
Standards that define how database organizes
data.
 Different data models are –
1. Relational Model
2. Entity-Relationship Model
3. Object-Based Data Model
4. Semi structured Data Model
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24. Data Models
1. Relational Model – Collection of tables to
represent both data and the relationship
among those data.
 Is Record based model.
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25. Data Models
2. Entity-Relationship Model : Collection of basic
objects called entities.
 It is based on entities and its relationship.
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26. Data Models
3. Object-Based Data Model: Object oriented
programming has become the dominant
software development methodology.
 It leads to develop an object oriented data
models which is extending the E-R model
with notions of encapsulation, methods
(functions) , and object entity.
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27. Data Models
4. Semi structured Data Model : This data
model permits the specification of data where
individual data items of the same type may
have different set of attributes.
 The Extensible Markup Language (XML) is
widely used to represent semi structured
data.
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28. Database Languages
 A DBMS provides a data-definition
language to specify the database
schema and a data-manipulation
language to express database queries
and updates.
 Data-definition and data-manipulation
languages are parts of single database
language.
 Ex. - SQL - Structured Query Language
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29. Database Languages
 Data-Manipulation Languages- which
enables users to access or manipulate
data as organized by the appropriate
data model.
 Access types (operations) – Retrieval,
Insertion, Deletion & Modification.
 There are two types of DMLs.
1. Procedural DMLs – What & How (data).
2. Declarative (Non procedural) DMLs –
What.
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30. Database Languages
 Data-Definition Language: Data
Definition Language (DDL) statements
are used to classify the database
structure or schema.
 It is a type of language that allows the
DBA or user to depict and name those
entities, attributes, and relationships that
are required for the application along
with any associated integrity and security
constraints.
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31. Database Languages
 Data-Definition Language: Here are the
lists of tasks that come under DDL-
 CREATE – used to create objects in the database.
 ALTER – used to alters the structure of the database.
 DROP – used to delete objects from the database.
 TRUNCATE – used to remove all records from a table,
including all spaces allocated for the records are
removed.
 COMMENT – used to add comments to the data
dictionary.
 RENAME – used to rename an object.
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32. Relational Database
 The relational model is the theoretical basis of
relational databases which is a technique or
way of structuring data using relations, which
are grid-like mathematical structures
consisting of columns and rows.
 Codd proposed the relational model for IBM.
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33. Relational Database
 In the relational model, all data is logically
structured within relations i.e. tables.
 Each relation has a name and is formed from
named attributes or columns of data.
 Each tuple or row holds one value per
attribute.
 The greatest strength of the relational model is
this simple logical structure that it forms. 33IBS Hyderabad

34. Relational Database
 Objectives of Relational Model:
1. To allow a high degree of data independence.
2. To provide considerable grounds for dealing with
data semantics, reliability, and redundancy
problems.
3. To allow the expansion of set-oriented data
manipulation languages.
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35. Relational Database
 Tables:
 Each table has multiple columns and each
column has a unique name.
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36. Relational Database
 Tables: Relational Model Terms -
 Relation: A relation is a table with columns and
rows.
 Attribute: An attribute is a named column of a
relation.
 Domain: A domain is the set of allowable values for
one or more attributes.
 Tuple: A tuple is a row of a relation.
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37. Relational Database
 Tables: Ex.
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38. Relational Database
 Data-Manipulation Language – The SQL query
language is nonprocedural.
 A query takes as input several tables/table and
always return a single table.
 SQL statement for finding the names of all
instructors in the History department.
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39. Relational Database
 Data-Manipulation Language : -
 The query specifies that those rows from the
table instructor where dept_name is History
must be retrieved and name attribute of these
rows must be displayed.
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40. Relational Database
 DMLs: .
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41. Relational Database
 Data-Manipulation Language : - Query may
involve information from more than one table.
 This query finds the instructors ID and of all
the instructors associated with a department
name department with budget greater than
$95000. 41IBS Hyderabad

42. Relational Database
 DMLs: .
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43. Relational Database
 Data-Definition Language: SQL provides a rich
DDL that allows one to define tables, integrity
constraints, assertions, etc.
 Following SQL DDL statement defines the
department table:
create table department
(dept_name char (20),
building char (15),
budget numeric (12,2));
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44. Relational Database
 Database Access from Application
Programs:
 SQL is a query language which deals with
creation and manipulation of data base and
data respectively.
 SQL does not support actions like input from
user, output to display & network
communication.
 Such actions and computations must be
written using general purpose languages like
C, C++, Java etc.
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45. Relational Database
 Database Access from Application
Programs:
 Application programs are programs that are
used to interact with the database for specific
application, like filling of the forms, doing
calculations, generation of reports, etc.
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46. Database Design
 DBMS are designed to manage large bodies
of information.
 These large bodies of information do not exist
in isolation.
 Here DBMS plays only supporting role by
providing required information or service.
 Database design mainly involves the design of
the database schema.
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47. Database Design
 Design Process:
1. Database Conceptual Framework – data
requirements, database structure.
2. Data Needs of the prospective database users –
outcome of the this phase is specification of user
requirements.
3. The designer needs to choose a data model and
translates user requirements into conceptual
schema of the database.
4. The designer reviews the schema to confirm data
requirements and its conflicts; focus is on data &
its relationship.
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48. Database Design
 Design Process:
5. A fully developed conceptual schema indicates
the functional requirements of the enterprise; at
this stage of conceptual design, the designer can
review the schema to ensure it meets functional
requirements.
6. Design to implementation can be taken into two
different ways – Logical design phase & Physical
design phase.
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49. Database Design
 Design Process; Example -
 Database design for a University: Points to be
considered.
 The University is organized into departments
(dept_name, bulding, budget).
 Each department has a list of courses it offers
(course_id, dept_name, credit, and prerequisites).
 Instructors are identified by their unique ID (name,
dept_name, salary).
 Students are identified by their unique ID (name,
dept_name, total_cred).
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50. Database Design
 Design Process; Example -
 Database design for a University: Points to be
considered.
 The University maintains a list of classrooms
(building, room_number & room_capacity).
 The university maintains a list of classes
(sections) taught (course_id, sec_id, year,
semester).
 The department has a list of teaching assignments
specifying, for each instructor, the section the
instructor is teaching.
 The University has a list of all student course
registration. 50IBS Hyderabad

51. Database Design
 Design Process-
 The Entity- Relationship Model – This model
uses a collection of basic objects, called
entities, and relationships among these
objects.
 Ex. Person, bank account;
 Entities are described in a database by a set
of attributes.
 Ex. ID, name, and salary may describe
instructor from university.
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52. Database Design
 Design Process-
 The Entity- Relationship Model –
 The external attribute ID is used to identify an
instructor uniquely.
 A relationship is an association among several
entities.
 Ex. A member relationship associates an
instructor with her department.
 Entity set – same types of entities.
 Relationship set – same type of relations.
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53. Database Design
 Design Process-
 The Entity- Relationship Model –
 The overall logical structure (schema) of a
database can be expressed graphically by an
entity-relationship (E-R) diagram.
 Several ways to draw these diagrams but most
popular is Unified Modeling Language (UML).
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54. Database Design
 Design Process-
 The Entity- Relationship Model –
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55. Database Design
 Design Process-
 The Entity- Relationship Model –
 Entity sets are represented by a rectangular
box with the entity set name in the header and
the attributes listed below it.
 Relationship sets are represented by a
diamond connecting a pair of related entity
sets. The name of the relationship is placed
inside the diamond.
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56. Database Design
 Design Process-
 The Entity- Relationship Model –
 In addition to entities and relationships, the E-
R model represents certain constraints to
which the contents of database must conform.
 Mapping Cardinalities, which expresses the
number of entities to which another entity can
be associated via a relationship set.
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57. Database Design
 Design Process-
 Normalization: Another commonly used
method of designing Relational database is.
 It creates schema to store information without
unnecessary redundancy and also allows us to
retrieve information easily.
 The approach is to design schemas that are in
an appropriate normal forms.
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58. Database Design
 Design Process-
 Normalization: To determine whether a
relation schema is in one of the desirable
normal forms, we need additional information
about the real world.
 Most commonly used approach is to use
functional dependencies.
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59. Database Design
 Design Process-
 Normalization: Example
 bad database design consists of –
 Repetition of Information.
 Inability to represent certain information.
 We shall discuss these problems with the help
of a modified database design for our
university example.
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60. Database Design
 Design Process-
 Normalization: Example.
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61. Database Design
 Design Process-
 Normalization: Example.
 Notice the present table contains repetition of
information with departments (building,
budget) – redundancy problem.
 This redundancy leads to inconsistency in
managing database.
 Another problem is “inability to represent
certain information”. (addition/deletion of
department without instructor is not possible).
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62. Data Storage and Querying
 A database system is partitioned into modules
that deal with each of the responsibilities of the
overall system.
 Functional Modules –
1. Storage Manager.
2. Query Processor Components.
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63. Data Storage and Querying
 Storage Manager is important because
database typically require a large amount of
storage space.
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64. Data Storage and Querying
 Main memory of computer cannot store this
much information, the information is stored on
disks.
 Data are moved between disk and main
memory as needed.
 Movement of data from disk to main memory
is slow relative to speed of CPU, therefore
database system structure the data so as to
minimize the need to move data between disk
and main memory.
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65. Data Storage and Querying
 The query processor simplifies database
access facility.
 It works at view level without understanding
the physical level implementation details.
 Database system translates and updates the
queries written in nonprocedural language, at
logical level into an efficient sequence of
operations at physical level with the help of
query processor.
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66. Data Storage and Querying
 Storage Manager: It provides interface
between the low-level data stored in database
and the application program and queries
submitted to the system.
 Is responsible for the interaction with the file
manager supported by operating system.
 It is also responsible for storing, retrieving, and
updating data in the database.
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67. Data Storage and Querying
 Storage Manager Components:
1. Authorization and integrity Manager.
2. Transaction Manager.
3. File Manager.
4. Buffer Manager.
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68. Data Storage and Querying
 Storage Manager data structures:
1. Data Files.
2. Data Dictionary.
3. Indices.
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69. Data Storage and Querying
 The Query Processor Components:
1. DDL interpreter.
2. DML Compiler.
3. Query evaluation engine.
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70. Transaction Management
 A transaction is a collection of operations that
performs a single logical function in a
database.
 The transaction Management consists of the
Concurrency-control manager and the
recovery manager.
 Each transaction is a unit of both atomicity and
consistency.
 It is programmer’s responsibility to define
properly the various transactions, so that each
preserves the consistency of the database.
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71. Transaction Management
 Recovery management ensures atomicity and
durability.
 The database system must perform failure
recovery, that is, detect system failures and
restore the database to the state that existed
prior to the occurrence of the failure.
 It is the responsibility of the concurrency-
control management to control the interaction
among the concurrent transactions, to ensure
the consistency of the database.
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72. Database Architecture
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73. Database Architecture
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74. Database Architecture
 The architecture of a database system is
greatly influenced by the underlying computer
system on which the database system runs.
 It can be centralized or client-server types.
 It can also be designed to exploit parallel
computer architectures.
 Distributed database span multiple
geographically separated machines.
 ODBC & JDBC is used to provide interface
between client and sever.
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75. Database Users and Administrators
 A primary goal of a database system is to
retrieve information from and store new
information into the database.
 People who work with a database can be
categorized as database users or database
administrators.
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76. Database Users and Administrators
 Four types of database Users – based on the
way they expect to interact with system.
1. Naïve User: Sophisticated users who
interacts with the system by invoking one of
the application programs.
 Ex, - Clerk adds new record to the existing
database using program specifically designed
to add record.
 A Form based user interface is preferred to
naive users.
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77. Database Users and Administrators
 Four types of database Users – based on the
way they expect to interact with system.
2. Application Programmers: are computer
professionals who write application programs.
 Rapid Application Development (RAD) tools
speeds up programming capabilities with
minimization of efforts to develop user
interfaces.
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78. Database Users and Administrators
 Four types of database Users – based on the
way they expect to interact with system.
3. Sophisticated Users: interacts with the
system without writing programs.
 Instead, they form their requests either using a
database query language or by using tools
such as data analysis software.
 Analysts who submit queries to explore data in
the database fall in this category. 78IBS Hyderabad

79. Database Users and Administrators
 Four types of database Users – based on the
way they expect to interact with system.
4. Specialized Users: are sophisticated users
who write specialized database applications
that do not fit into the traditional data-
processing framework.
 Ex.- Computer Aided Design, Knowledge
based expert systems.
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80. Database Users and Administrators
 Database Administrator: One of the main
reason for using DBMSs is to have central
control of both the data and the programs that
access those data.
 A person who has such central control over
the system is called a database Administrator
(DBA).
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81. Database Users and Administrators
 Database Administrator: Functions of a
DBA-
1. Schema definition – The DBA creates the
original database schema by executing a set
of data definition statements in the DDL.
2. Storage structure and access-method
definition –
3. Schema and physical-orginzation
modification -
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82. Database Users and Administrators
 Database Administrator: Functions of a
DBA-
4. Granting of authorization for data access -
5. Routing maintenance – like, backup, free
space management, monitoring jobs and
performance of the database.
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83. Reviews
 Database System Applications.
 Purpose of Database systems.
 View of Data.
 Database Language.
 Relational Database.
 Database Design.
 Database Architecture.
 Database Users and DBA.
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84. Thank You!
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