View
1.254
Download
0
Category
Tags:
Preview:
DESCRIPTION
Citation preview
Database System
Lecturer: Mr. Prum Chan Samedy, MScITTel: 012 456-896E-mail: chan_samedy@yahoo.com
Bachelor of Science in Information Technology
Database system 2
Objectives
After finished this course students able to design to manage large bodies of information. Management of data involves both designing structure for storage of information and providing mechanisms for the manipulation of information.
Data Management– Build an Entity-Relationship model for a relational DBMS– Implement the database in MS Access/SQL Server– Normalize tables– Produce SQL coding to manage data
Application Development– Plan and design an application system– Implement an application in MS Access
Database system 3
Fundamental of
Database systems, Elmasri & Navatthe
Class References
Database system 4
Chapter 1:
Introduction Databases and
Database users
Database System
Database system 5
Outline
Basic Definitions Typical DBMS Functionality Example of a Database (UNIVERSITY) Advantages of Using the Database Approach Database Users
Database system 6
Basic Definitions- Data VS Information
DATA: Facts concerning people, objects, vents or other entities. Databases store data.INFORMATION: Data presented in a form suitable for interpretation. Data is converted into information by programs and queries.
Figure 1.1 Input-process-output
Database system 7
Example of Data
Database system
Why every employees in company need information?
Shopping in supermarket
Database system 9
Basic Definitions – Database VS DBMS
DATABASE:
DATABASE MANAGEMENT SYSTEM (DBMS) :
A software system that enables users to define, create, and maintain the database and that provides controlled access to this database.
Database system
Basic Definitions – Database System
DATABASE SYSTEM:
Database System =DBMS+Database
The DBMS software together with the data itself. Sometimes, the applications are also included.
Oracle, SQL Server,DB2, MySQL, Infomix,…
Database system 11
Basic Definitions – Metadata
Metadata
“Data about data” Description of fields Display and format instructions
Structure of files and tables Security and access rules Triggers and operational rules
Example of Metadata
Database system 12
Basic Definitions –Sample of Metadata
Sample of Metadata
Database system 13
Simplified database system environment
A simplified database system environment
Database system
Database application program
A software program that interacts with the database by issuing an appropriate request (typically an SQL statement) to the DBMS.
Database system
Database Overview- Why Use a DBMS?
Using a DBMS to manage data has many advantages:
– Data independence – Sharing of data among multiple applications – Data integrity and security – Concurrent access and crash recovery– Data administration – Reduced application development time
Database system 16
Database Users-1
Users may be divided into– Those who actually use and control the database
content, and those who design, develop and maintain database applications (called “Actors on the Scene”), and
– Those who design and develop the DBMS software and related tools, and the computer systems operators (called “Workers Behind the Scene”).
Database system 17
Database Users-2
Actors on the scene– Database administrators:
Responsible for authorizing access to the database, for coordinating and monitoring its use, acquiring software and hardware resources, controlling its use and monitoring efficiency of operations.
– Database Designers/Ananyst: Responsible to define the content, the structure, the
constraints, and functions or transactions against the database. They must communicate with the end-users and understand their needs.
Database system 18
Database Users-3
Application programmer/Application DeveloperThey access the data from programs written in high-level language such as Visual basic or C++,C#, Java. The application programmers design systems such as payroll, Inventory, and billing.
End userThey use the data for queries, reports and some of them update the database content.
Database system 19
Exercise 1.1
Indicate which type of user would perform the following functions for a payroll system in a large company:
A. Write an application program to generate and print the checks.
B. Change the address in the database for an employee who has moved.
C. Create a new user account for a newly hired payroll clerk
Database system 20
RDBMS
Relational Database Management System (RDBMS) – Relational Database is a collection of relations
(table) Oracle, SQL Server, DB2, My SQL,…
User tables Data dictionary
Database system 21
Index
199011913 19959999
19860001 19901913 19911123 19959999
Indexcolumn
4327 2271 . . .
200000190000...
Prum Chan DaraKeo Rithy...
00427699...
19871992 . . .
5648180000Pich Oudam19131990
Dept_NoSalaryEmp_NameSerial_ No
Hire_Year
Row
Field
[EMPLOYEE table]
[DEPARTMENT table]
Dept_No Department Area
5648432722710381...
SystemsPersonnelGeneral affairsSales...
P.PKDKPKK...
Sample of Relational Database
Database system 22
Database Architecture
Single tier Architecture Two-tier Architecture Three-tier Architecture
Database system 23
DBMSSoftware
Database
a. Single tier:All on one machine Access by terminals
Single tier
Database system 24
Client/Server (Two tier )
DBMS manages data resources like an operating system manages hardware resources
DBMSServer
Software
DBMSServer
Software
Databasecontainingcentralized
shared data
Application#1
Application#2
Application#3
Front-End/Client
b. Two-Tier:Server with many clients
Database system 25
Three-tier architecture
c. Three-tier:Two kings of DBMS
Connected by Middleware
DBMS IServer
Software
Database
Middleware
Application#1
Application#2
DBMS IIServer
Software
Database
Application#3
Applicatio4#3
Front-End/ClientFront-End/Client
Database system
Also call Distributed SystemsSolutions are distributed between client PC’s and one or more servers.
Three-tier architecture
Database system 27
Exercise 1.2
Specify whether each system would be single-tiered, two-tiered, or three-tiered.
a. The Happy Nights motel chain allows local managers to purchase a franchise. They can install and use the DBMS of their choice for their reservation system. The only requirement is that they be able to connect and communicate with the central office’s system.
b. The Sticky Wicket Company has home offices in Detroit and branches in Chicago and Baltimore. The inventory and parts database is distributed with each branch keeping its own inventory. One central DBMS located in Detroit allows instant ordering of supplies through the central office.
Database system 28
Recommended