Aug 14, · Hello, I have a question about NLS_LANG. Let's suppose we have two servers: an Oracle Database Server and an application Server. Each server is installed on a separate machine. So Oracle is the Server and the Web Server is the client. Userenv and NLS of Oracle_ Lang 1. The most common use of userenv. Therefore, transcoding occurs when the character set of client program and session is inconsistent. If byte loss occurs during transcoding, the real data stored is the data after the loss. As for the garbled code we see, it is because the stored data will be transcoded into. NLS_LANG cannot be changed by ALTER SESSION, NLS_LANGUAGE and NLS_TERRITORY can. However NLS_LANGUAGE and /or NLS_TERRITORY cannot be set as "standalone" parameters in the environment or registry on the client. Evidently the "right" solution is, before logging into Oracle at all, setting the following environment variable.