# Determine Oracle session client character set

character-setoracle

I know how the database characterset (NLS_CHARACTERSET in select * from v$nls_parameters;) and the client character set (the client environment setting NLS_LANG) interact. What I can't find out however, is how or if I can determine, for an established session, what Oracle thinks the current client characterset is. Is this possible at all? Note: SELECT * FROM NLS_SESSION_PARAMETERS; does not include the character set (on 10g2). To make absolutely clear what I'd like to accomplish: 1. NLS_LANG is set in client environment to an arbitrary value (for example GERMAN_GERMANY.WE8MSWIN1252) 2. Database application[*] starts and establishes a connection/session to the Oracle database. 3. Database application[*] wants to "ask" Oracle (not its OS environment) what the client character set is Oracle will assume. [*]: If the db application is sqlplus, the example would look as follows: ... sqlplus /nolog connect user/pass@example *magic command*; CLIENT CHARACTERSET = ...  Jack's note in his answer raises two important points: • With Oracle, who does the characterset translation. Is it the client-library code or is it done on the server side? • As it appears it is the client, the client would need expose this setting — what the client lib/tool assumes this setting is. Is there any of the Oracle client libs/tools (sqlplus, OCI/OCCI, Pro*C, …) that can be queried for what it thinks this setting is? #### Best Answer I am a little doubtful that this is exactly what you are looking for, but host echo %nls_lang%; ENGLISH_UNITED KINGDOM.WE8ISO8859P1  shows the client nls_lang environment variable on the client. I don't think there will be a SQL query you can run to give the 'current' setting because AFAIK the server is not aware of what translation is done client-side, so any command to show the current setting will have to be native to the client - I used SQL Developer for the above command, but I assume it will work the same in SQL*Plus --edit only the client knows their character set as well -- it is not available "in the database" and the character set describes what is stored in database. the client makes their desired translated to character know [sic] to the database via the NLS_LANG settting. If you were on 11.1+, you might have some joy with v$session_connect_info, because:

This information is pushed by OCI to the server ats login time.

But I discovered it would still depend on how you are connecting, eg from the JDBC Thin Driver you aren't using OCI and so the information isn't pushed