The document is from Trinity Institute of Professional Studies and discusses database management systems (DBMS). It defines a DBMS as software used to create and maintain databases. It describes the key functions of a DBMS including defining and constructing the database, manipulating data through queries and updates, and allowing concurrent access. The document outlines several main characteristics of the database approach like self-describing schemas, insulation between programs and data, and supporting multiple views of data.

1. TRINITY INSTITUTE OF PROFESSIONAL STUDIES
Sector – 9, Dwarka Institutional Area, New Delhi-75
Affiliated to Institution of G.G.S.IP.U, Delhi
BBA DBMS 108
Assistant Professor
Ruchika Bajaj

2. TRINITY INSTITUTE OF PROFESSIONAL STUDIES
Sector – 9, Dwarka Institutional Area, New Delhi-75
Database Management System
(DBMS)
• Database Management System (DBMS): A
software system used to create and maintain
database.
• Database System: The DBMS software having
data . Sometimes, the applications are also
included.

3. TRINITY INSTITUTE OF PROFESSIONAL STUDIES
Sector – 9, Dwarka Institutional Area, New Delhi-75
DBMS Functionality
• Define a database : in terms of data types,
structures and constraints
• Construct or Load the Database on a
secondary storage medium
• Manipulating the database : querying,
generating reports, insertions, deletions and
modifications to its content
• Concurrent Processing and Sharing by a set of
users and programs – yet, keeping all data
valid and consistent

4. TRINITY INSTITUTE OF PROFESSIONAL STUDIES
Sector – 9, Dwarka Institutional Area, New Delhi-75
Main Characteristics of the Database
Approach
• Self-describing nature of a database system: A
DBMS catalog stores the description of the
database. The description is called meta-data).
This allows the DBMS software to work with
different databases.
• Insulation between programs and data: Called
program-data independence. Allows changing
data storage structures and operations without
having to change the DBMS access programs.

5. TRINITY INSTITUTE OF PROFESSIONAL STUDIES
Sector – 9, Dwarka Institutional Area, New Delhi-75
Main Characteristics of the Database
Approach
• Data Abstraction: A data model is used to
hide storage details and present the users
with a conceptual view of the database.
• Support of multiple views of the data: Each
user may see a different view of the
database, which describes only the data of
interest to that user.
• Sharing of data and multiuser transaction
processing :

6. TRINITY INSTITUTE OF PROFESSIONAL STUDIES
Sector – 9, Dwarka Institutional Area, New Delhi-75
Instances and Schemas
• Schema – overall description of the database
• ex: cust_id : string;
cust_name : string;
cust_street : string;
cust_city : string;
• 2 Types of schema :
– Physical schema: database design at the physical level
– Logical schema: database design at the logical level
• Instance – the actual content of the database at a
particular point in time

7. TRINITY INSTITUTE OF PROFESSIONAL STUDIES
Sector – 9, Dwarka Institutional Area, New Delhi-75
Data independence
• Physical Data Independence – the ability to
modify the physical schema without changing
the logical schema
• Logical Data Independence- the ability to
modify the logical schema without changing
the external view

8. TRINITY INSTITUTE OF PROFESSIONAL STUDIES
Sector – 9, Dwarka Institutional Area, New Delhi-75
The Entity-Relationship Model
• It is collection of entities and relationships
– Entity: real life “object” in the enterprise
– Relationship: an association among several
entities

9. TRINITY INSTITUTE OF PROFESSIONAL STUDIES
Sector – 9, Dwarka Institutional Area, New Delhi-75
Database Users
Actors on the scene
– Database administrators(DBA): responsible for
authorizing access to the database, for co-ordinating
and monitoring its use.
• Casual : access database occasionally when needed
• Naïve or Parametric : they know little about Dbms and
databases.
• Sophisticated : these include business analysts,
scientists, engineers, others thoroughly familiar with
the system capabilities..

10. TRINITY INSTITUTE OF PROFESSIONAL STUDIES
Sector – 9, Dwarka Institutional Area, New Delhi-75
Advantages of Using the Database
Approach
• Controlling redundancy in data storage and in
development and maintenence efforts.
• Sharing of data among multiple users.
• Restricting unauthorized access to data.
• Providing persistent storage for program
Objects (in Object-oriented DBMS’s –
• Providing Storage Structures for efficient
Query Processing