dba lecture 1

7/29/2019 DBA Lecture 1

1/26

Modern Database Management 6thEdit ionJeffrey A . Ho ffer, Mary B . Presco tt, Fred R.

McFadden

Ins truc tor : Mr. Sadiq ShahDate: 10/09/12

1

Chapter 1:The Database Environment


2/26

Chapter 1

Tentative Grading Policy

2

20% Mid Tem Exam

70% Final Exam

5% Project/Assignments/Presentation

5% Quizzes


3/26

Chapter 1

Class Etiquettes

3

Respect each others

Keep your mobiles switched off

Be careful of class timing

Late comer may be not allowed

Delay talks with colleagues

Avoid interruption in class


4/26

Chapter 1

Definitions

4

Data: facts, text, graphics, images, sound,

video segments that have some meaning.

Database: An organized collection of logicallyrelated data

Information: Data processed to be useful in

decision making

Metadata: Data that describes data


5/26

Chapter 1

5

Figure 1-1a Data in Context

Large volume of facts, difficultto interpret or make decisions

based on


6/26

Chapter 1

6

Figure 1-1b Summarized data

Useful information that managers can use for

decision making and interpretation


7/26

Chapter 17

Table 1-1 Metadata

Descriptions of the properties or characteristics of the

data, including data types, field sizes, allowablevalues, and documentation


8/26

Chapter 1

Disadvantages of File Processing

8

Program-Data DependenceAll programs maintain metadata for each file they use

Data Redundancy (Duplication of data)

Different systems/programs have separate copies of the same

data Limited Data Sharing

No centralized control of data

Lengthy Development Times

Programmers must design their own file formats

Excessive Program Maintenance

80% of of information systems budget


9/26

Chapter 19

Figure 1-2 Three file processing systems at Pine

Valley FurnitureDuplicate

Data


10/26

Chapter 1

Problems with Data Dependency

10

Each application programmer must maintaintheir own data

Each application program needs to includecode for the metadata of each file

Lack of coordination and central control

Non-standard file formats


11/26

Chapter 1

Problems with Data Duplication

11

Waste of space to have duplicate data

Causes more maintenance headachesThe biggest Problem:

When data changes in one file, could

cause inconsistenciesCompromisesdata integri ty


12/26

Chapter 1

SOLUTION:

The DATABASE Approach

12

Central repository of shared data

Data is managed by a controlling

agent

Stored in a standardized,

convenient formRequires a Database Management System (DBMS)


13/26

Chapter 1

Database Management System

13

A DBMS is a data storage and retrieval system

which permits data to be stored non-redundantlywhile making it appear to the user as if the data is

well-integrated.


14/26

Chapter 1

Database Management System

14

DBMS manages dataresources like an operating

system manages hardware

resources

DBMS Databasecontainingcentralizedshared data

Application#1

Application

#2

Application#3


15/26

Chapter 1

Advantages of Database Approach

15

Program-Data Independence Metadata stored in DBMS, so applications dont need to

worry about data formats

Results in: increased application development and

maintenance productivityMinimal Data Duplication

Leads to increased data integrity/consistency


16/26

Chapter 1

Advantages of Database Approach

16

Improved Data Sharing Different users get different views of the data

Enforcement of StandardsAll data access is done in the same way

Better Data Accessibility/ Responsiveness Use of standard data query language (SQL)

Security, Backup/Recovery, Concurrency Disaster recovery is easier


17/26

Chapter 1

Costs and Risks of the

Database Approach

17

Up-front costs: Installation Management Cost and Complexity

Conversion Costs

Ongoing Costs Requires New, Specialized Personnel

Need for Explicit Backup and Recovery

Organizational Conflict Old habits die hard


18/26

Chapter 118

Figure 1-5

Client/server

system forPine Valley

Furniture

Company

Fi 1 6 C t i i (Pi V ll F it C )


19/26

Chapter 119

Figure 1-6 Customer invoice (Pine Valley Furniture Company)

Application program functions:

inserting new data, updatingexisting data,

deleting existing data, reading data for display


20/26

Chapter 1

The Range of

Database Applications

20

Personal Database standalone desktopdatabase

Workgroup Database local area network (


21/26

Chapter 121

Figure 1-7

Typical data

from apersonal

computer

database


22/26

Chapter 122

Figure 1-8 Workgroup database with local area network


23/26

Chapter 123

Figure 1-9 An

enterprise

datawarehouse


24/26

Chapter 1

Components of the

Database Environment

24

CASE Tools computer-aided software engineering

Repository centralized storehouse of metadata

Database Management System (DBMS) software formanaging the database

Database storehouse of the data

Application Programs software using the data

User Interface text and graphical displays to users

Data Administrators personnel responsible for maintainingthe database

System Developers personnel responsible for designingdatabases and software

End Users people who use the applications and databases


25/26

Chapter 125

Figure 1-10

Componentsof the

database

environment


26/26

Chapter 126

End of lecture 1

dba lecture 1

Documents