Matakuliah : Web Database
Tahun
: 2008
Web Database Implementation
Session 8, 9 and 10
Last Session Review:
•Complication in Web Database
•Limitation in Web Database Method
•Web Database Design Method
•Web Data Analysis
•Logical Web Data Design
•Physical Web Database Design
2
Agenda:
•Physical Database Design
•Physical Web Database Design
•Web Architecture
•Client Processing
•Server Processing
•Java
•Implementation Choice
3
Objectives:
•Student can implement Physical Database Design,
and Physical Web Database Design
•Student can choose the suitable Web
Architecture for the web database application
•Student can choose to implement Client
Processing or Server Processing or combination
•Student can use Java Technology
4
Physical Database Design
• What is Physical Database Design?
– The process of producing a description of the implementation of the database
on secondary storage; it describes the base relations, file organizations, and
indexes used to achieve efficient access to the data, and any associated
integrity contraints and security measures.
• Property to select physical representations?
– speed
– capacity
– Resilient to catastrophes
• Implementation of physical Database Design highly depend on the
DBMS, thats why it is important to choose DBMS according to
physical database implementation needs
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Physical Database Design (cont.)
• Consideration when implement Physical Database Design?
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Logical Database Design
Quantities and volatility of data
The ways in which the data is to be used
Transaction properties
Cost
• After choosing DBMS for Physical Database Design, ERD Normal can be
implemented according to DBMS
• Steps of the physical database design methodology?
– Translate logical data model for target DBMS: involve the design of the ERD Normal
and general contraints using the available functionality of the target DMBS
– Design file organizations and indexes: choosing the file organizations and indexes for
the base relations
– Design User View: deciding how each user view should be implemented
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Physical Database Design (cont.)
• Translate logical data model for target DBMS
– Design Entities, Relations, Attributes from ERD Normal
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Name the entities (tables) and attributes
Add primary keys, alternate keys (if needed), and foreign keys (if needed)
Add Referential integrity
For each attributes:
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Decides its domain
Decides optional default value
Decides whether the attribute can hold nulls
Decides whether the attribute is derived and if so how it should be computed
– Design representation of derived data
• Decides whether data should be stored in database or calculate every time it is
needed.
• Consideration:
– Additional cost to store and keep it consistent
– Cost to calculate it
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Physical Database Design (cont.)
• Translate logical data model for target DBMS
– Design General Constraints
• Integrity constraints: required data, domain constraints and entity adn
referential integrity
• Design of constraints depend on the DBMS
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Physical Database Design (cont.)
• Design file organizations and indexes
– Objective:
• Determine the optimal file organizations to store the database and its indexes
that are required to achieve accetable performance
– Type of file depend to DBMS
– Activities in Design File Organization and Indexes:
• Analyze Transaction: to understand the functionality of the transaction that will
run on the database and to analyze the important transaction
• Choose File Organizations: to determine an efficient file organization for each
database
• Choose Indexes: to determine whether adding indexes will improce the
performance of the system
• Estimate Disk Space Requirements: to estimate the amount of disk space that will
be required by the database
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Physical Database Design (cont.)
• Design file organizations and indexes
– File Organizations Technology
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Heap Files
Hash Files
Indexed Sequential Office Acess Method (ISAM)
B*-Tree
Clusters
– Indexes Technology
• Multi-level Indexes
• Indexed Sequential Access Method
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Physical Database Design (cont.)
• Design User View
– To design the user view that were identified during the requirements
collection and analysis stage
– Can be implemented using Views
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Physical Database Design (cont.)
• Case Study Physical Database Design:
A relational table is designed to represent details of projects. Its
columns are project number, employee number of project leader,
project name, host department and head of host department. Each
project has a unique number, a leader and a host department. Each
department has only one head, but can host many projects.
Make the necessary implementation physical database planning and
all scripts for this case.
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Physical Web Database Design
• What is Physical Web Database Design?
– Designs how the Web pages are to be implemented and connected to the
database system
– Software tools and techniques that can be used to make a database system
accessible via the web
• Database system component may be implemented as extensions to
the servers or browsers, or may be external to the web
• Implementation should analyze and decide how to access the
database from the client or server and at which of these to process
the application
• Implementation should also consider the web architecture
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Web Architecture
• Web applications should be build in client server architecture
• Client server architecture type:
– Two-Tier Client Server Architecture
– Three-Tier Client Server Architecture
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Web Architecture
• Two Tier Client Server Architecture
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Web Architecture (cont.)
• Three Tier Client Server Architecture
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Web Architecture (cont.)
• Advantages Three Tier Client Server Architecture:
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“Thin” client, requiring less expensive hardware
Application maintenance centralized
Easier to modify or replacing one tier without effecting others
Separating business logic from database function
Maps quite naturally to web environment
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Client Side Processing
• What is Client Side Processing?
– Client side processing=client side scripting
– Approach that enable application executed by the Web client system rather
then the server
– Basically client side processing suitable for small-scaled functionality, such as
web pages animations, and simple data validation and calculation.
– Could avoid a number of possibility slow connection.
– Client should have minimal resources to process the information
– Common language used in Client Side Processing: Java (Java Applet or
JavaScript)
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Client Side Processing (cont.)
• Two basic approaches to client side processing:
– Browser Extension
• The browser is extended to give additional functionality
• By using plug-ins (in Netscape or Internet Explorer), ActiveX Control (Internet
Explorer) or using Java Applets and JavaScript
• How to create Browser Extension:
– Script Language Interpreters, e.g. JavaScript
– Bytecode Interpreter, to implement the Java Virtual Machine (JVM) to interpret Java
– Access to Operating System Resources
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Client Side Processing (cont.)
• Two basic approaches to client side processing:
– External Application
• Existing database clients on the client system, and are launched by the web
browser to provide additional services or other application such as legacy system
cover by middleware
• Similar to using a server site gateway to execute other systems
• Advantage:
– Can interact directly with the DBMS using its database transaction management
system
• Disadvantage:
– Interaction between the client and server are not controlled by the DBMS transaction
Management
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Client Side Processing (cont.)
• Advantages of Client Server Processing:
– Distribution of processing
– Speed of feedback
– Added Web-page functionality
• Disadvantages of Client Server Processing:
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Environment Dependencies
Security
Download Time
Programming Limitation
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Client Side Processing (cont.)
• Case Study Client Side Processing
An organization want to make website that has fast response and
attractive with many dynamic content.
Is Client Side Processing is the right choice to make this kind of
website? Please explain.
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Server Side Processing
• What is Server Side Processing?
– Approach that enable application to do processing in server rather then in
client
• Procedures in Server Side Processing?
– Data must be sent from a client to a server
– The data must be processed on the server
– Result must be sent from the server to client
• Two Different Approach of Service Side Processing:
– HTML Preprocessors, such as Active Server Pages (ASP) and Java Server
Pages (JSP), known as Server Side Scripting
– CGI Scripts, maybe written in different language
• What ever techniques used, there must be a method of making a
database connection from that language
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Server Side Processing (cont.)
• Server Side Scripting
– What is Server Side Scripting?
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Program is embedded in HTML
Web page contains instructions that are executed
Pre-processing system from HTML
Directive can be embedded into Web pages, and are then processed by the server
when the pages are delivered to a user. The Web server processes these pages
and dynamically produces an HTML documents that is sent to the browsers.
• Allow fragment if code inserted into HTML or its variants
– Advantages:
• Lots of different and competing technology that can be implemented
– Disadvantages:
• No truly cross platform scripting language
• More difficult to compile
• Specific server may determine the choice of pre-processor
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Server Side Processing (cont.)
• Server Side Scripting
– Server Side Scripting Languages:
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ASP (Active Server Pages)
ASP.Net
JSP (Java Server Pages)
PHP
Server Side Java Scripts
SSI (server Side Include)
Cold Fusion
Etc.
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Server Side Processing (cont.)
• CGI (Common Gateway Interface)
– What is CGI?
• HTML embedded in program. A program is execute to create HTML
• An interface by which executable programs can be created to execute on the
server, and which are separated from the HTML Web Pages
• Can be written in many languages
– CGI Disadvantages:
• Efficiency
• Security
• Identity
– CGI Languages:
• Perl
• Ingres-Ice
• O2-O2Web
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Server Side Processing (cont.)
• Case Study Server Side Processing
An organization want to make website that has fast response and
attractive with many dynamic content.
Can we use Server Side Processing for this case? Please explain and
give the possible constraints if we use Server Side Processing.
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Java
• What is Java?
– Programming language for implemetation processing in Web Database
system, can be use in Client side processing or Server Side Processing
– In Client Side Processing  Java Applets, JavaScript
– In Server Side Processing (Server Side Scripting and CGI) Java Servers
Pages (JSP), Java Servlets or Java CGI
• Advantages of JAVA:
– The programming language it self
– Java Virtual Machine (JVM)
– Library of classes and interfaces
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Java (cont.)
• How will Java be Used?
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To Access Database  JDBC
To implement Java in Client Side Processing  Java Applet
To implement Java in Server Side Processing  Java Servlets
To implement Java in CGI  Java CGI
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Implementation Choice
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How to Choose between Client Side Processing or Server Side Processing?
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Consideration:
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Distributed System
Workload and Speed
Scale of Functionality
Sufficient Resources in Server and Client
Dependent
Consideration
Client Side
Server Side
Distributed System
Distribute function to clients
Centralize function in Server
Workload and Speed
Give fast feedback
Slower feedback, depend on the Network and
Server Workload
Scale of Functionality
Small-Scale Functionality
Large-Scale Functionality
Sufficient Resource
Client should have sufficient Resources
Server should have sufficient Resources
Dependent
Depend to Client Environments
Independent to Client Environment
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Implementation Choice (cont.)
• How to Choose between Languages?
– Consideration:
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Client Processing
Appearance
Database Detection and Validation
Graceful Degradation
Browser Detection
Feature Bloat
User Interface Issue
– User Interface and Web
– User Interface and Intranet
– User Interface and Control
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Implementation Choice (cont.)
• Case Study Implementation Choice
The director of an e-commerce company reqiores advice on whether
to adopt Java or JavaScript for implementation. One consideration
is that the appearance of Web pages is very important. As is the
widest possible distribution to Web users.
Write a short report weighing out the pros and cons
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Summary
• Implementation of Web Database Application should consider the
physical database design and physical web database design
• There is no one solution to every problem (no-silver-bullet). There
are lots of choice to implement web database application.
• Choose the right implementation by regarding several
considerations.
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Next Session:
•Overview Transaction
•Incomplete or Abandoned Transaction
•Problem in Transaction
•Locking and Deadlock
•Web Database Transaction
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End of
Web Database Implementation
Thank you
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