Configuring Locale and Character Sets Using the NLS

Configuring Locale and Character Sets Using the NLS_LANG Environment Variable

The NLS_LANG environment variable determines the language of the user interface and the globalization behavior for components such as SQL*Plus, exp, and imp.

It sets the language and territory used by the client application and the database user session. It also declares the character set for entering and displaying data by the client application.

The NLS_LANG environment variable uses the following format:

NLS_LANG=language_territory.characterset

In this format:

language specifies the language used for displaying Oracle messages, sorting, day names, and month names
territory specifies the conventions for default date, monetary and numeric formats
characterset specifies the encoding used by the client application

In most cases, this is the Oracle character set that corresponds to the Windows ANSI Code Page as determined by the System Locale.

The NLS_LANG parameter on Windows can be set

in Registry under the subkey corresponding to a given Oracle home,
as an environment variable.

When you install Oracle Database components and the NLS_LANG parameter is not yet set in the Registry subkey of the target Oracle home, Oracle Universal Installer sets the NLS_LANG parameter to a default value derived from the operating system locale for the current user.