10.2. Using NLS Parameters
Ultimately, Oracle globalization support options are defined by NLS parameter settings. By assigning values to specific NLS parameters, you can control when, where, and how Oracle will utilize globalization support functionality. These settings can be specified in a variety of ways, and their effects may vary accordingly.
On the server side, NLS parameters are read from initialization parameter settings at instance startup time. The values are stored in the data dictionary, as are the database and national character set settings.
On the client side, NLS parameters can be defined as environment variables (such as NLS_LANG), or they can be set at the session level by using the ALTER SESSION statement. NLS parameters ...