If you create a database using the database configuration assistant (DBCA), Oracle sets the default character set according to the operating system locale settings. You can change the character set during the database creation based on your needs. The character set is selected when the database is created with the CREATE DATABASE statement and cannot be changed afterward. To change a character set, the database must be re-created and the data reloaded. Consult the Oracle National Language Support Guide for your Oracle release to determine the character set that is right for your data.
If you have upgraded your database and client applications to ArcGIS 9.2 or greater, you do not have to set the NLS_LANG variable on the client. However, if you are using a server and/or client prior to ArcSDE 9.2, to properly convert and preserve the characters, you must set the Oracle NLS_LANG variable in the client application's system environment. Consult the ArcSDE 9.1 Configuration and Tuning Guide for Oracle .pdf file installed with ArcSDE for information on setting this variable.
Tip
For a complete list of character encoding standards supported by your Oracle database and their naming conventions, please refer to the Oracle National Language Support Guide.
