Choosing a Locale with the NLS_LANG Environment Variable

A locale is a linguistic and cultural environment in which a system or program is running. Setting the NLS_LANG environment parameter is the simplest way to specify locale behavior for Oracle software. It sets the language and territory used by the client application and the database. It also sets the client character set, which is the character set for data entered or displayed by a client program.

The NLS_LANG parameter sets the language and territory environment used by both the server session (for example, SQL statement processing) and the client application (for example, display formatting in Oracle tools).

While the default NLS_LANG behavior defined during installation is appropriate for most situations, you might want to modify the NLS environment dynamically during the session. To do so, you can use the ALTER SESSION statement to change NLS_LANGUAGE, NLS_TERRITORY, and other NLS parameters.

Note:

You cannot modify the setting for the client character set with the ALTER SESSION statement.

The ALTER SESSION statement modifies only the session environment. The local client NLS environment is not modified, unless the client explicitly retrieves the new settings and modifies its local environment.