DROP TABLE TIMES;P AR T IIITWO-MINUTE DRILLCUSTOMIZE LANGUAGE-DEPENDENT BEHAVIOR FOR THE DATABASE AND INDIVIDUAL SESSIONS• GLOBALIZATION COVERS ASPECTS OF DATA PRESENTATION, CALENDARS, AND DATES, INCLUDING DATES, NUMBERS, AND LINGUISTIC LOCALIZATIONS

13. Tidy up:

P AR T III

Two-Minute Drill

Customize Language-Dependent Behavior for the

Database and Individual Sessions

• Globalization covers aspects of data presentation, calendars, and dates,

including dates, numbers, and linguistic localizations.

• A character set is a defined encoding scheme for representing characters as a

sequence of bits.

• The number of characters that a character set can represent is limited by the

number of bits the character set uses for each character.

• The Unicode standards are an international standard for character encoding,

which is intended to include every character that will ever be required by any

computer system.

• The number of languages supported by Oracle depends on the platform,

release, and patch level of the product.

• The language used will determine the language for error messages and also set

defaults for date language and sort orders.

• Binary sorting may be acceptable for a seven-bit character set, but for character

sets of eight bits or more the results are often inappropriate.

• Query V$NLS_VALID_VALUES to see the available character sets, sort orders,

territories, and languages.

• Globalization can be specified at any and all of these five levels, in increasing

order of priority: database, instance, client environment, session, and statement.

• The database character set is used to store all the data in columns of type

VARCHAR2, CLOB, CHAR, and LONG.

• Two types of Unicode are supported as the National Character Set:

AL16UTF16 and UTF8.

• There are two tools provided to assist with deciding on character set change:

the Database Character Set Scanner and the Language and Character Set File

Scanner.

• The key client-side environment variable is NLS_LANG. The full specification

for this is a language, a territory, and a character set.

Work with Database and NLS Character Sets

• Oracle’s default sort order is binary.

• Linguistic sorting means that rather than replacing each character with its

numeric equivalent, Oracle will replace each character with a numeric value that

reflects its correct position in the sequence appropriate to the language in use.

• The Locale Builder is a graphical tool that can create a customized globalization

environment, by generating definitions for languages, territories, character

sets, and linguistic sorting.

• Applications are made time-zone aware by specifying a time zone in which

the database operates, and then using the TIMESTAMP WITH TIME ZONE and

TIMESTAMP WITH LOCAL TIME ZONE data types.

• The usual DATE and TIMESTAMP data types are always normalized to the

database time zone on storage and displayed unchanged when selected.

• The database time zone can be set at creation time in the CREATE DATABASE

command and adjusted later with ALTER DATABASE SET TIME_ZONE.

Self Test