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Overview of Globalization Support in Oracle9iAS

This chapter contains the following topics:

Globalizing Internet Applications

It is increasingly important for businesses to make their Internet applications available with appropriate locale characteristics, such as language and currency formats, to users around the world. The Oracle9i Application Server (Oracle9iAS) is fully internationalized to provide a global platform for developing and deploying Internet applications.

Building an Internet application or Web site for Oracle9iAS requires good globalization practices in development and deployment. This book describes recommended globalization practices.

Chapter 4 contains information about a multilingual demo that is included with Oracle9iAS.

Globalization Concepts

You need to be familiar with the following concepts to understand the rest of this book:

Locale

Locale refers to a language, a character set, and the region (territory) in which the language is spoken. Information about the region includes formats for dates and currency, for example. The primary languages of the United States and Great Britain are both forms of English, but the two territories have different currencies and different conventions for date formats. Therefore, the United States and Great Britain are different locales.

Character Set

A character set defines the binary values that are associated with the characters that make up a language. For example, the ISO-8859-1 character set can be used to encode most Western European languages.

Unicode

Unicode is a universal character set that defines binary values for characters in almost all languages. Unicode characters can be encoded as follows:

In 1 to 4 bytes in the UTF-8 character set
In 2 or 4 bytes in the UTF-16 character set
In 4 bytes in the UTF-32 character set

Designing a Global Internet Application

There are several approaches to designing global Internet applications. This book discusses two approaches: monolingual and multilingual.

You can design a monolingual Internet application so that it supports several instances. Each instance supports a different locale. Users with different locale preferences must invoke the instance that serves their locale.

You can design a multilingual Internet application to support several locales with one instance. All users, regardless of locale, can invoke the same instance.

Both designs include one centralized database that uses a Unicode character set.

This section contains the following topics:

Monolingual Internet Application Architecture

Figure 1-1 shows the design of a monolingual Internet application.

Figure 1-1 Monolingual Internet Application Architecture

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The clients (in English, Japanese, Hebrew, and Thai locales) communicate with separate instances of Oracle9iAS through HTTP connections. One instance of the application runs in the same locale as one of the Oracle9iAS instances. For example, the English application runs in the same locale as Oracle9iAS Instance 1. The English and Japanese applications and their Oracle9iAS instances are running on Server A, and the Hebrew and Thai applications and their instances are running on Server B. Each Oracle9iAS instance communicates with the Unicode database. The instances communicate with the database through Oracle Net.

The client character set for the English locale, for example, is ISO-8859-1. The instance of Oracle9iAS that is associated with the English locale, Instance 1, uses the Oracle character set WE8MSWIN1252 to communicate with the database. The database character set is a Unicode character set.

See Also:

"Using a Centralized Database"

Table 1-1 shows the advantages and disadvantages of deploying monolingual Internet applications. As the number of locales increases, the disadvantages outweigh the advantages of the monolingual design. This type of application design is suitable for customers who support only one or two locales.

Table 1-1 Advantages and Disadvantages of Monolingual Internet Application Design

Advantages	Disadvantages
You can separate the support of different locales into different servers. This allows locales to be supported in different time zones. Work load can be distributed accordingly.	There are more Oracle9iAS servers to administer.
Writing the code is simpler than for a multilingual Internet application.	The Internet application requires more testing resources to certify it on each Oracle9iAS instance.
	You must configure Oracle9iAS for each instance of the application.
	You must maintain a server for each locale regardless of the amount of work that is demanded of it. Load-balancing is possible only among a group of Oracle9iAS instances that support the same locale.
	Supporting multilingual content is difficult.

Multilingual Internet Application Architecture

Figure 1-2 shows the design of a multilingual Internet application.

Figure 1-2 Multilingual Internet Application Architecture

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The clients (in English, Japanese, Hebrew, and Thai locales) communicate with one Oracle9iAS instance through HTTP connections. Each client can use a different character set because Oracle9iAS is configured to support several locales simultaneously. The Oracle9iAS instance and the database communicate through Oracle Net. Both the Oracle9iAS instance and the database use Unicode character sets. The Unicode character sets do not have to be the same.

See Also:

"Using a Centralized Database"

In order to support several locales in a single application instance, an application should:

Process character data in Unicode so that it can support data in any language
Dynamically detect the user's locale and adapt to the locale by constructing HTML pages in the correct language and cultural conventions
Dynamically determine the character set to use for HTML pages and convert content from Unicode to the HTML page encoding and vice versa

Table 1-2 shows the advantages and disadvantages of deploying multilingual Internet applications.

Table 1-2 Advantages and Disadvantages of Multilingual Internet Application Design

Advantages	Disadvantages
You can use one Oracle9iAS configuration, which reduces maintenance costs.	Multilingual applications are more complex to code than monolingual applications. They must be able to detect locales dynamically and use Unicode. This is costly if you only need to support one or two languages.
Performance tuning and capacity planning do not depend on the number of locales.
Supporting additional languages is relatively easy. You do not need to add more machines for the new locales.
You can test the application for several locales in a single testing environment.
The application can support multilingual content.

Using a Centralized Database

A centralized Unicode database is a feature of both the monolingual approach and the multilingual approach to developing globalized Internet applications. Using a centralized database has the following advantages:

It provides a complete view of your data. For example, you can query for the number of customers worldwide or the worldwide inventory level of a product.
It is easier to manage a centralized database than several distributed databases.

The database character set should be Unicode. You can use Unicode to store and manipulate data in several languages. Unicode is a universal character set that defines characters in almost all languages in the world. Oracle9i databases can store Unicode data in one of the following encoding forms:

UTF-8: Each character is 1 to 4 bytes long.
UTF-16: Each character is either 2 or 4 bytes long.
UTF-32: Each character is 4 bytes long.
See Also:

"Configuring Oracle HTTP Server for Multilingual Support"

Oracle9i Globalization Support Guide in the Oracle Database Documentation Library

1Overview of Globalization Support in Oracle9iAS