1 INTRODUCTION TO DATABASE MANAGEMENT SYSTEM L E C T U R E This repository of slides is intended to support the named chapter. The slide repository should be used as follows: Copy the file to a unique name for your course and unit. Edit the file by deleting those slides you don’t want to cover, editing other slides as appropriate to your course, and adding slides as desired. Print the slides to produce transparency masters or print directly to film or present the slides using a computer image projector. Each slide includes instructor notes. To view those notes in PowerPoint, click left on the View Menu; then click left on Notes View sub-menu. You may need to scroll down to see the instructor notes. The instructor notes are also available in hard copy as the Instructor Guide to Accompany Systems Analysis and Design Methods, 5/ed. Chapter 7 - Data Modeling and Analysis

The database environment To be able to function, an organisation needs information, e.g. list of books in a library, customer details in a retail business, specifications of cars and their components for a car manufacturer Information may be defined as data represented in a meaningful form. Same data shown in different ways will provide different information to different viewers

A major requirement of any computer system is to store and retrieve data in a way that is meaningful to the end user – so the core of any Information System is data, which is to be transformed into information through data modelling.

Data: Database: Information: Definitions Meaningful facts, text, graphics, images, sound, video segments. Database: An organized collection of logically related data. Information: Data processed to be useful in decision making.

Metadata: Data that describes the properties or characteristics of other data. Does not include sample data Allows database designers and users to understand the meaning of the data

A database is a collection of related information. What is Databases? Often abbreviated DB. A database is a collection of related information. A database is a collection of information that is organized so that it can easily be accessed, managed, and updated. For example, a phone book is a database of names, addresses and phone numbers.

A collection of information organized in such a way that a computer program can quickly select desired pieces of data. You can think of a database as an electronic filing system

Traditional databases are organized by fields, records, and files. A field is a single piece of information; a record is one complete set of fields; and a file is a collection of records. For example, a telephone book is similar to a file. It contains a list of records, each of which consists of three fields: name, address, and telephone number.

Database Management System (DBMS) To access information from a database, you need a database management system (DBMS). This is a collection of programs that enables you to enter, organize, and select data in a database. OR A Database Management System (DBMS) is a software tool that facilitates creating, maintaining, and manipulating an information database.

The following are examples of database applications: DMBS is a collection of programs that enables you to store, modify, and extract information from a database. There are many different types of DBMSs, ranging from small systems that run on personal computers to huge systems that run on mainframes. The following are examples of database applications: computerized library systems automated teller machines flight reservation systems

Requests for information from a database are made in the form of a query. In fact, most of today's database systems are referred to as a Relational Database Management System (RDBMS), because of their ability to store related data across multiple tables.

Relational Database Management System (RDBMS) A relational database management system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by E. F. Codd. Most popular databases currently in use are based on the relational database model.

A short definition of an RDBMS is: a DBMS in which data is stored in tables and the relationships among the data are also stored in tables. The data can be accessed or reassembled in many different ways without having to change the table forms.

Relational Database Management System (RDBMS) A relational database management system (RDBMS) is a program that lets you create, update, and administer a relational database. Relational Database Management System a type of database management system (DBMS) that stores data in the form of related tables. An important feature of relational systems is that a single database can be spread across several tables.

Some of the more popular relational database management systems include: Microsoft Access Filemaker Microsoft SQL Server MySQL Oracle

What is Record? In the context of a relational database, a row—also called a record or tuple—represents a single, structured data item in a table. In simple terms, a database table can be thought of as consisting of rows and columns or fields. Each row in a table represents a set of related data, and every row in the table has the same structure.

EMPNO FIRSTNME LASTNAME WORKDEPT JOB 000010 Christine Haas A00 President 000020 Michael Thompson B01 Manager 000120 Sean O'Connell Clerk

In a relational database, entities are represented as tables. What is Entity? The first step in developing a database design is to identify the types of data to be stored in database tables. A database includes information about the entities in an organization or business, and their relationships to each other. In a relational database, entities are represented as tables.

An entity is a person, object, or concept about which you want to store information. Some of the entities described in the sample tables are employees, departments, and projects. EMPNO FIRSTNME LASTNAME WORKDEPT JOB 000010 Christine Haas A00 President 000020 Michael Thompson B01 Manager 000120 Sean O'Connell Clerk

There are characteristics to each piece of data in each row. What is Field/Column? Within a relational table, each row of data in the table is a collection of related data values. There are characteristics to each piece of data in each row. Columns are used to identify and classify each piece of data. Each column in a table must have a name that is unique for that table.

The data type and length specify the type of data and the maximum length that are valid for the column. Data types may be chosen from those provided by the database manager or you may choose to create your own user-defined types.

Database Applications Banking: all transactions Airlines: reservations, schedules Universities: registration, grades Sales: customers, products, purchases Online retailers: order tracking, customized recommendations Manufacturing: production, inventory, orders, supply chain Human resources: employee records, salaries, tax deductions

Data Manipulation Language (DML) Language for accessing and manipulating the data. DML also known as query language. Structured Query Language (SQL) is the most widely used query language.

Relational Model Attributes

A Sample Relational Database

Architecture for a Database System

The DBMS Manages the Interaction Between the End User and the Database.

The Database System Components Hardware Computer Peripherals Software Operating systems software DBMS software Applications programs and utilities software

People Systems administrators Database administrators (DBAs) Database designers Systems analysts and programmers End users

Procedures Instructions and rules that govern the design and use of the database system Data Collection of facts stored in the database

Types of Database Systems Number of Users Single-user Desktop database Multiuser Workgroup database Enterprise database

Location Use Centralized Distributed Transactional (Production) Decision support Data warehouse