1. System Analysis and Design
System Design
- Mr. Ahmad Al-Ghoul
In this sequence we will discuss the components of a database management system, then we will Describe Web-based data design

2. System Analysis and Design System Design
learning Objectives
Understand the components of a database management system (DBMS)
Describe Web-based data design, including characteristics of Web-Based Design, Internet terminology, connecting a Database to the Web, and data Security
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System Analysis and Design System Design

3. System Analysis and Design System Design
DBMS Components
A DBMS provides an interface between a database and users who need to access the data
In addition to interfaces for users, database administrators, and related systems, a DBMS also has a data manipulation language, a schema and subschemas, and a physical data repository
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System Analysis and Design System Design

4. System Analysis and Design System Design
DBMS Components
Interfaces for Users, Database Administrators, and Related Systems
When users, database administrators, and related information systems request data and services, the DBMS processes the request, manipulates the data, and provides a response
Users: typically work with predefined quires and switchboard commands, but also use a query language to access stored data
Query language: A query language allows a user to specify a task without specifying how the task will be accomplished. Some query languages use natural language commands that resemble ordinary English sentences.
SQL (structured query language): is a query language that allows PC users to communicate with servers and mainframe computers.
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System Analysis and Design System Design

5. System Analysis and Design System Design
DBMS Components
Interfaces for Users, Database Administrators, and Related Systems
Database Administrators
A DBA is responsible for DBMS management and support
DBA is concerned with data security and integrity, preventing unauthorized access, providing backup and recovery, audit trails, maintaining the database, and supporting users needs
Related information systems
A DBMS can support several related information systems that provide input to, and require specific data from, the DBMS
A data manipulation language (DML) controls database operations, including storing, retrieving, updating, and deleting data
Commands in this category allow you to manipulate data in existing database objects. The most popular commands in this category are INSERT, UPDATE, and DELETE.
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System Analysis and Design System Design

6. System Analysis and Design System Design
DBMS Components
Schema
The complete definition of a database, including descriptions of all fields, tables, and relationships, is called a schema
You also can define one or more subschemas.
A subschema is a view of the database used by one or more systems or users. A subschema defines only those portions of the database that a particular system or user needs or is allowed to access.
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System Analysis and Design System Design

7. System Analysis and Design System Design
DBMS Components
Physical Data Repository
The data dictionary which describes all data elements included in the logical design, is transformed into a physical data repository, which also contains the schema and subschemas
The physical repository might be centralized, or distributed at several locations
To resolve potential database connectivity and access problems, companies use
ODBC – open database connectivity: is an industry-standard protocol that makes it possible for software from different vendors to interact and exchange data uses SQL statements
JDBC – Java database connectivity: JDBC enables Java applications to exchange data with any database that uses SQL statements and is JDBC-compliant
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System Analysis and Design System Design

8. Web-Based Database Design
Characteristics of Web-Based Design
In a Web-based design, the Internet serves as the front end, or interface for the database management system. Internet technology provides enormous power and flexibility
In internet the system is not tied to any specific combination of hardware and software
Access to the database require only a Web browser and an Internet connection
Web-based systems are popular because they offer ease of access, cost-effectiveness, and worldwide connectivity
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System Analysis and Design System Design

9. Web-Based Database Design
Web-based design characteristics [1]
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System Analysis and Design System Design

10. Web-Based Database Design
Internet Terminology
Web browser: An application that enables the user to navigate, or browse the Internet and display Web pages on his or her local computer.
Web page: Text and multimedia documents that are found on the World Wide Web.
HTML – Hypertext Markup Language: Is the language used to write Web pages for the Internet.
Web server: A computer that is used to store and house Web sites.
Web site: A collection of related Web pages.
Intranet: A private, company-owned network that provides Web-based access to internal users
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System Analysis and Design System Design

11. Web-Based Database Design
Internet Terminology
Extranet: An extension of a company intranet that allows access by external users, such as customers and suppliers.
Protocols: A set of standards that govern network data transmission. Also, preset conditions used by firewalls to determine whether or not to allow traffic to pass.
Web-centric: A strategy or approach that emphasizes a high degree of integration with other Web-based components. A Web-centric architecture follows Internet design protocols and enables a company to integrate the new application into its e-commerce strategy.
Clients: Workstations that users interact with in a client/server design. These workstations, or computers, are supplied data, processing services, or other support from other computers, called servers.
Servers: Computers in a client/server design that supply data, processing, and services to the client workstations.
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System Analysis and Design System Design

12. Web-Based Database Design
Connecting a Database to the Web
Database must be connected to the Internet or intranet
The database and Internet speak two different languages
Database are created and managed using various programming languages and commands that have nothing to do with HTML
To bridge the gab, it is necessary to use middleware
Middleware: is software that connects dissimilar applications and enables them to communicate and exchange data. For example, middleware can link a departmental database to a Web server that can be accessed by client computers via the Internet or a company intranet.
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System Analysis and Design System Design

13. Web-Based Database Design
When a client workstation requests a Web page (1), the Web server uses middleware to generate a data query to the database server (2). The database server responds (3) and middleware translates the retrieved data into an HTML page that can be sent by the Web server and displayed by the user's browser (4).
[1]
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System Analysis and Design System Design

14. Web-Based Database Design
Data Security
Web-based data must be totally secure, yet easily accessible to authorized users
To achieve this goal, well-designed systems provide security at three levels:
the database itself, the Web server, and the telecommunication links that connect the components of the system
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System Analysis and Design System Design

15. System Analysis and Design System Design
Sequence Summary
DBMS components include interfaces for users, database administrators, and related systems; data manipulation language; a schema; and physical data repository
The physical repository might be centralized, or distributed at several locations
In a Web-based design, the Internet serves as the front end, or interface for the database management system.
Internet terminology include, web browser, web page, web server, web site, HTML, intranet, extranet, protocols, web-centric, clients, and servers
When connecting database to the Internet they speak two different languages you need To bridge the gab, it is necessary to use middleware
Middleware: is software that connects dissimilar applications and enables them to communicate and exchange data
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System Analysis and Design System Design

16. System Analysis and Design System Design
Sequence Summary
In this Sequence we have
Described the components of a database management system (DBMS)
Described Web-based data design, including characteristics of Web-Based Design, Internet terminology, connecting a Database to the Web, and data Security
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System Analysis and Design System Design

17. System Analysis and Design System Design
Reference
[1] System Analysis and Design, Sixth Edition
Authors: Gary B. Shelly, Thomas J. Cashman and Harry J. Rosenblatt
Publisher: SHELLY CASHMAN SEWIES.
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System Analysis and Design System Design