This document introduces database management systems. It defines a database as a collection of interrelated data used to efficiently retrieve, insert, and delete data organized in tables, schemas, views, and reports. A database management system (DBMS) is software that manages databases and provides interfaces to perform operations like creating, storing, updating, and querying data. The document outlines characteristics, applications, and components of DBMS, as well as conceptual, representational, and physical data models used to design databases at different levels of abstraction.

1. Introduction
of
Database Management System

2. Introduction: Database
 The database is a collection of inter-related data which is used to
retrieve, insert and delete the data efficiently. It is also used to
organize the data in the form of a table, schema, views, and
reports, etc.
 For example: The college Database organizes the data about the
admin, staff, students and faculty etc.
 Using the database, you can easily retrieve, insert, and delete the
information.

3. Database Management System
 Database Management System is a software which is used to
manage the database. For example: MySQL, Oracle etc are a very
popular commercial database which is used in different
applications.
 DBMS provides an interface to perform various operations like
database creation, storing data in it, updating data, creating a table
in the database and a lot more.

4. Characteristics of DBMS
 It can provide a clear and logical view of the process that
manipulates data.
 DBMS contains automatic backup and recovery procedures.
 It can reduce the complex relationship between data.

5. Conti…
 It is used to support manipulation and processing of data.
 It is used to provide security of data.
 It can view the database from different viewpoints according to
the requirements of the user.

6. Applications of DBMS
 Railway Reservation System
 Library Management System
 Banking System
 Education Sector (Schools ,Colleges & Universities)
 Social Media Sites
 Broadcast communications
 Online Shopping
 Manufacturing
 Airline Reservation System

7. DBMS Components
 Hardware
 Software
 Data
 Users
 Procedures

8. Data Models in DBMS
 A Data Model in Database Management System (DBMS), is the
concept of tools that are developed to summarize the description
of the database.
 It is classified into 3 types:

9. Conceptual Data Model :
 Conceptual data model, describes the database at a very high level
and is useful to understand the needs or requirements of the
database.
 This model is used in the requirement gathering process i.e.,
before the Database Designers start making a particular database.
One such popular model is the Entity/Relationship model (ER
model).

10. Entity-Relationship Model
 Entity-Relationship (ER) Model is based on the notion of real-world entities and
relationships among them. While formulating real-world scenario into the database
model, the ER Model creates entity set, relationship set, general attributes and
constraints.
 ER Model is best used for the conceptual design of a database.
 ER Model is based on −
 Entities and their attributes.
 Relationships among entities.

11. Conti…
 Entity − An entity in an ER Model is a real-world entity having properties
called attributes. Every attribute is defined by its set of values called domain.
For example, in a school database, a student is considered as an entity. Student
has various attributes like name, age, class, etc.
 Relationship − The logical association among entities is called relationship.
Relationships are mapped with entities in various ways. Mapping cardinalities
define the number of association between two entities.

12. Conti…
 Mapping cardinalities −
one to one
one to many
many to one
many to many

13. Representational Data Model :
 This type of data model is used to represent only the logical part
of the database and does not represent the physical structure of
the databases. The representational data model allows us to focus
primarily, on the design part of the database. A popular
representational model is Relational model.

14. Relational Model

15. 3. Physical Data Model :
 Ultimately, all data in a database is stored physically on a
secondary storage device such as discs and tapes. This is stored in
the form of files, records and certain other data structures. It has
all the information of the format in which the files are present and
the structure of the databases, presence of external data structures
and their relation to each other.

16. Schemas & Instance
 The overall description of the database is called as the Database
Schema
 Databases change over time when we insert or delete the
information.
The collection of information stored in the database at a
particular moment is called as an instance of the database