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Introduction:

What is a Data Base?

Lecture: Fundamentals of Data Base

SystemsAbdul Rahman Sherzad

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Brainstorming

In what context have you heard of the term

data base or database?

Have you ever used a database system?

In which situations in our everyday life do we

interact with data base systems?

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Database System Application

Banking:

For customer information, accounts, and loans,

and banking transactions.

Universities:

For student information, course registrations, and

grades.

Sales:

For customer, product, and purchase information.

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Database System Application

Airlines:

For reservations and schedule information.

Credit card transactions:

For purchases on credit cards and generation ofmonthly statements printed record of accountactivity.

Human resources: For information about employees, salaries, payroll

taxes and benefits, and for generation ofpaychecks salary voucher.

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Database System Application

Telecommunication: For keeping records of calls made, generating

monthly bills, maintaining balances on prepaid callingcards, and storing information about the

communication network. Finance:

For storing information about sales, and purchases offinancial instruments such as stocks and bonds.

Manufacturing: For management of supply chain and for tracking

production of items in factories, inventories of itemsin warehouses/stores, and orders for items.

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Brainstorming

Summary

Databases play a critical role in almost all

areas in which computers are used!

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What is Database?

Definition

Elmasri & Navathe (2007):

A database is a collection of related data.

By data, we mean known facts that can be

recorded and that have implicit meaning.

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What is Database?

Definition

Properties of a database:

A database represents some aspect of the real

world, sometimes called mini-world or the

universe of discourse (UoD).

Changes to the mini-world are reflected in the

database.

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What is Database?

Definition

Properties of a database:

A database is a logically coherent consistent or

logical collection of data with some inherent

meaning.

A random assortment of data cannot correctly be

referred to as a database.

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What is Database?

Definition

Properties of a database:

A database is designed, built, and populated with

data for a specific purpose.

It has an intended group of users and some

preconceived applications in which these users

are interested.

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Databases

Size and Complexity

A database can be of any size and complexity

Example for a small database:

Personal DB with addresses with only a few hundred

records (each with a simple structure)

Example for a large database:

Amazon.com: with more than 20 million of books, CDs,eBooks, magazines, journals and etc. In a DB with the

size of 2 terabytes

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Definition:

Database Management System

A Database Management System (DBMS) is a

collection of interrelated data and set of

programs to access those data.

The collection of data, usually referred to as

the database, contains information related to

an enterprise.

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Definition:

Database Management System

Elmasri & Navathe (2007):

A database management system (DBMS) is acollection of programs that enables users to

create and maintain a database.

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Definition:

Database Management System

A DBMS fulfills several purposes:

defining databases constructing databases

manipulating databases

sharing databases among various users andapplications

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DBMS

MS Access

MySQL (Open Source)

SQL-Server (Microsoft)

Oracle

PostgreSQL

FoxPro

SQLite

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Definition:

Application Program

Elmasri & Navathe (2007), p. 6:

An application program accesses the database

by sending queries or requests to the DBMS.

A query (question, inquiry) is the interaction with the

database, e.g. retrieving or manipulating data.

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Definition:

Database System

The database, the DBMS software, and the

application program together are called adatabase system.

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Overview

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Example of a database system

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Actors around Database

Systems

What roles do people take around adatabase system?

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Actors around Database

Systems

What roles do people take around a

database system?

End users DB designers

DB administrators

Application programmers

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Actors around Database

Systems

End users:

the people who will use the DB when it is finished

normally little technical knowledge use of the DB

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Actors around Database

Systems

Database Designers:

the database designers conceptually design and

implement the DB

analyze requirements for the DB

gathering of information about the application field

conceptual schema. (conceptual = of an idea or

concept)

choice of DBMS

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Actors around Database

Systems

Database Administrators:

when the database is designed and implemented

it is handed over to the DB administrator person responsible for the DB during its lifetime

management of user accounts, hardware

resources, backups, etc.

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Actors around Database

Systems

Application Programmers:

programmers that write programs that use the DB

programmers of a graphical user interface (GUI)

for the database

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Thats all for today

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