This document provides an introduction to database systems. It begins by explaining that databases allow for efficient data storage and management which enables good decision making. The document then defines key database concepts like data, information, databases, and DBMS. It describes how databases solve problems with data management compared to file systems by reducing redundancy and inconsistencies. Finally, it outlines the typical components of a database system including hardware, software, users, procedures, and data.

1. DATABASE SYSTEMS
M AHMAD ABBAS
Dept. of Computer SciencE
INTRO LACTURE

2. INTRODUCTION
 Good decisions require good information derived
from raw facts
 Data is managed most efficiently when stored in a
database
 Databases evolved from computer file systems
 Understanding file system characteristics is
important

3. BASICS
 First we will talk about basic,
 Data
 Information
 Database
 DBMS etc…

4. DATA V INFORMATION
Data
 Data is the raw material that is to be processed for
information
 Data is useless unless it is processed or has been
made into something meaningful
 Data has no meaning when it has not been
interpreted
For Example:
 During census, data of all citizens is collected
 Companies collect data by survey to know the opinion of
people about their product

5. DATA V INFORMATION CONTINUED..
Information
 Information is processed data
 The data that can be made useful is known as
information
 Information is the meaning that has been formed
with the help of data
For example:
 Census data is used to get information about total population
of a country
 Survey data is summarized into information to present to
management of the company

6. DATABASE
 A database is a gathering of data, stored on a
server
 The data is organized in a way it can easily be
retrieved, managed and edited in significant ways
by the end-user
 Mostly used Database model is Relational
database model
 Stored Data in the form of rows and columns

7. WHY DATABASES?
 Databases solve many of the problems
encountered in data management
 Used in almost all modern settings involving data
management:
 Business
 Research
 Administration
 Important to understand how databases work and
interact with other applications

8. COMPONENTS OF DATABASE SYSTEM

9. OBJECTIVES OF TODAY’S LECTURE
 Know common database terminology
 Understand requirements and uses of data
 Realize the importance and need for databases
in problem-solving
 Understand the different types of databases and
their differences

10. DBMS
 Database management system (DBMS) helps you
to create and manage database,
 DBMS is a computer software providing the
interface between users and database.
For example,
 SQL server (Microsoft), Oracle (ORACLE), DB2 (IBM) etc..

11. DBMS CONT’D
 Software system that is designed to allow users to
create , design and manipulate databases.
 Mostly commonly used commands to create,
retrieve and manipulate databases
 DML(Data Manipulation Language ) Commands
 DDL(Data Definition Language) Commands
 DCL (Data Control Language) Commands

12. STRUCTURE OF THIS SEMESTER
Database
Fundamentals
Relational
Model
Normalization
Conceptual
Modeling
Query
Languages
Advanced
SQL
SQL Server Databases
Apps
0. Intro 1. Design 3. Applications
Newbie Users Designers
Databases
2. Querying
Developers

13. ROLE AND ADVANTAGES OF THE DBMS
 DBMS is the intermediary between the user and the
database
 Database structure stored as file collection
 Can only access files through the DBMS
 DBMS enables data to be shared
 DBMS integrates many users’ views of the data

15. ROLE AND ADVANTAGES OF THE DBMS
(CONT’D.)
 Advantages of a DBMS:
 Improved data sharing
 Improved data security
 Minimized data inconsistency
 Improved data access
 Improved decision making
 Increased end-user productivity

16. TYPES OF DATABASES
 Databases can be classified according to:
 Number of users
 Database location(s)
 Expected type and extent of use
 Single-user database supports only one user at a time
 Desktop database: single-user; runs on PC
 Multiuser database supports multiple users at the
same time
 Workgroup and enterprise databases

17. EVOLUTION OF FILE SYSTEM DATA
PROCESSING
 Reasons for studying file systems:
 Complexity of database design is easier to understand
 Understanding file system problems helps to avoid
problems with DBMS systems
 Knowledge of file system is useful for converting file
system to database system
 File systems typically composed of collection of file
folders, each tagged and kept in cabinet
 Organized by expected use

18. 18DatabaseSystems,9thEdition

19. PROBLEMS WITH FILE SYSTEM DATA
PROCESSING
 File systems were an improvement over manual
system
 File systems used for more than two decades
 Understanding the shortcomings of file systems aids in
development of modern databases
 Even simple file system retrieval task required
extensive programming
 Ad hoc queries impossible
 Changing existing structure difficult

20. DATA REDUNDANCY
 File system structure makes it difficult to combine data
from multiple sources
 Vulnerable to security breaches
 Organizational structure promotes storage of same data
in different locations
 Islands of information
 Data stored in different locations is unlikely to be
updated consistently
 Data redundancy: same data stored unnecessarily in
different places

21. DATA REDUNDANCY (CONT'D.)
 Data inconsistency: different and conflicting
versions of same data occur at different places
 Data anomalies: abnormalities when all changes in
redundant data are not made correctly
 Update anomalies
 Insertion anomalies
 Deletion anomalies

22. DATABASE SYSTEMS
 Database system consists of logically related data
stored in a single logical data repository
 May be physically distributed among multiple storage
facilities
 DBMS eliminates most of file system’s problems

23. 23DatabaseSystems,9thEdition

24. THE DATABASE SYSTEM ENVIRONMENT
 Database system: defines and regulates the
collection, storage, management, use of data
 Five major parts of a database system:
 Hardware
 Software
 People
 Procedures
 Data
24Database Systems, 9th Edition

25. THE DATABASE SYSTEM ENVIRONMENT
(CONT'D.)
 Hardware: all the system’s physical devices
 Software: three types of software required:
 Operating system software
 DBMS software
 Application programs and utility software

26. THE DATABASE SYSTEM ENVIRONMENT
(CONT'D.)
 People: all users of the database system
 System and database administrators
 Database designers
 Systems analysts and programmers
 End users
 Procedures: instructions and rules that govern the
design and use of the database system
 Data: the collection of facts stored in the database

27. THE DATABASE SYSTEM ENVIRONMENT
(CONT'D.)
 Database systems are created and managed at
different levels of complexity
 Database solutions must be cost-effective as well
as tactically and strategically effective
 Database technology already in use affects
selection of a database system

28. And
 Be Confident and Be determine to achieve
something ahead in life!!