最早参考了http://www.dbanotes.net/ 中相关文件

Oracle 10g 关于 NLS 的环境变量发生了一点变化:

For RDBMS 7.2.x version the variable is called ORA_NLS.

For version 7.3.x the variable is called ORA_NLS32.

For Oracle 8, 8i and 9 variable is called ORA_NLS33.

For Oracle 10g the variable is called ORA_NLS10.

ORA_NLS33 的设置值:

ORA_NLS33 = $ORACLE_HOME/ocommon/nls/admin/data

而 ORA_NLS10 只需要设置:

ORA_NLS10 = $ORACLE_HOME/nls/data

定义了 ORA_NLS10 则不需要单独定义 ORA_NLS33 等参数了。

目前应该仍然是向后兼容 ORA_NLS33 的。

PURPOSE

The purpose of this document is to provide summarized information on when
environment variable ORA_NLS (ORA_NLS32, ORA_NLS33, ORA_NLS10) needs to be set.
 
SCOPE & APPLICATION

Database administrators - Oracle Support Analysts

=========================================================================


For RDBMS 7.2.x version the variable is called ORA_NLS.
For version 7.3.x the variable is called ORA_NLS32.
For Oracle 8, 8i and 9 variable is called ORA_NLS33.
For Oracle 10g the variable is called ORA_NLS10.

Note:
In this document, ORA_NLSxx term should be generic for all versions.

Please be aware that your ORACLE_HOME variable should also be set correctly

A) On UNIX we recommend to set ORA_NLSxx always in the User enviroment of the 
   ORACLE user.

The variable is used to locate the NLS libraries when:

1. If you create a database with any character set other than US7ASCII 
   on Oracle version 7.x and up. 

   If you are using version 7 then you must set the environment variable ORA_NLS32 to:
 
    ORA_NLS32 = $ORACLE_HOME/ocommon/nls/admin/data

    If you are using a Oracle8, 8i or 9 version set the ORA_NLS33 environment variable to:

    ORA_NLS33 = $ORACLE_HOME/ocommon/nls/admin/data

    If you are using a Oracle10G version set the ORA_NLS10 environment variable to:

    ORA_NLS10 = $ORACLE_HOME/nls/data

   There is no need to define ORA_NLS32 or ORA_NLS when using oracle 8 or higher.
   There is no need to define ORA_NLS33, ORA_NLS32 or ORA_NLS when using oracle 10G.

   When you try to create a database without setting ORA_NLSxx parameter you will 
   have the error:

    ORA-12701: "CREATE DATABASE character set is not known"

   If you are creating database upon installation of Oracle software, 
   you need to add ORA_NLSxx in the startup file of the oracle software owner.

2. When database is already created and SQL Net (or Net8) connections need 
   to be established, ORA_NLSxx is used by the listener and client software
   to define date/time format masks and perform characterset conversions.
   So make sure that in the client's and (!) listener environment the ORA_NLSxx also is set:

   Please note that we don't advise to use a version 9 listener for a version 8 database
   or a version 10 listener for a version 9 or 8 database seen there where many changes 
   to the NLS layers between those versions.

   If you are using a SQL*PLUS or listener Oracle7 version, set the environment variable:

    ORA_NLS32 = $ORACLE_HOME/ocommon/nls/admin/data

   If you are using a SQL*PLUS or listener Oracle8, 8i or 9 version, set the environment variable:

    ORA_NLS33 = $ORACLE_HOME/ocommon/nls/admin/data

   If you are using a SQL*PLUS or listener Oracle10G version, set the environment variable:

    ORA_NLS10 = $ORACLE_HOME/nls/data

   There is no need to define ORA_NLS32 or ORA_NLS when using oracle 8 or higher.
   There is no need to define ORA_NLS33, ORA_NLS32 or ORA_NLS when using oracle 10G.


Note:
-----
   * When establishing connection through SQL*Net, connecting to an Oracle8 
     database with a Unicode UTF8 character set, make sure you are using 
     SQL*Net version 2.3.4 and higher. Otherwise you will get an error, as 
     SQL*Net V2.3.4 and higher is required to connect to a UTF8 database.
    (i.e. ORA-3106) 
   * In some circumstances you will see that Oracle recommends to set 
     ORA_NLS10 to $ORACLE_HOME/nls/data/9idata instead of $ORACLE_HOME/nls/data
     The why is explained in  Note 292942.1 Language and Territory definitions
     changed in 10g vs 9i and lower 

     Please note that unless you have a good reason, we strongly recommend to have
     ORA_NLS10 set to $ORACLE_HOME/nls/data.
     Using $ORACLE_HOME/nls/data/9idata must be considerd as a temporary workaround.


3. For characterset conversion and date/time format support:

     set the ORA_NLS32 environment variable for the release 7.3.x environment 

     set the ORA_NLS33 environment variable for the version 8,8i and 9 environment 

     set the ORA_NLS10 environment variable for the version 10G environment 

   Verify that the client has the correct NLS environment variables set (like NLS_LANG).
   For more info on that subject please see:

    Note 158577.1 NLS_LANG Explained (How does Client-Server Character Conversion Work?)
    Note 241047.1 The Priority of NLS Parameters Explained.

   An error is generated when release 7.3 NLS code tries to load a version 8 
   character set. 

   There is no need to define ORA_NLS32 or ORA_NLS when using oracle 8 or higher.
   There is no need to define ORA_NLS33, ORA_NLS32 or ORA_NLS when using oracle 10G.

4. On WINDOWS platforms there is normally no need to define ORA_NLSxx.

   If you want however you can define this in the correct HOMEx entry in the registry,

   HKEY_LOCAL_MACHINESOFTWAREORACLE for version 7
   or
   HKEY_LOCAL_MACHINESOFTWAREORACLEHOMEx for version 8 and 9
   or
   HKEY_LOCAL_MACHINESOFTWAREKEY_ for version 10

   The default directory for windows is 

   for 8.0: ORA_NLS33=%ORACLE_HOME%NLSRTL33DATA

   for 8i and 9i: ORA_NLS33=%ORACLE_HOME%ocommonnlsADMINDATA

   for 10g: ORA_NLS10=%ORACLE_HOME%nlsDATA

   See Note 73963.1 Using multiple ORACLE HOMES on Windows platform 

   Please do NOT define ORA_NLSxx as (system) ENVIROMENT variable on windows.
   Please do NOT define ORACLE_HOME and/or ORACLE_BASE  as (system) ENVIROMENT 
   variable on windows as this will invalidate the working of ORA_NLSxx.


5. When Developer is installed.

Note1:
ORA_NLSxx does not need to be set for Developer 6.0.

For Oracle version 8.x, if we connect from the client and use Developer 
version 1.6.1 then ORA_NLS33 needs to be set:
 
  $ORACLE_HOME/ocommon/nls/admin/datad2k 

For other versions it should point to:

 $ORACLE_HOME/ocommon/nls/admin

Note2:
$ORACLE_HOME/ocommon/nls/admin/data2k subdirectory is created by 
Developer version 1.6.1 only. This is caused by the fact that this 
version of Developer uses two versions of NLSRTL library at once: version 3.2 
for Oracle common RDBMS libraries (known as RSF on Windows) and version 3.3 
for Forms processing. As these two NLSRTL versions needs different *.nlb files,
two data directories are created: 'data' for 3.2 and 'datad2k' for 3.3. 

NLSRTL 3.2 files are pointed to by the ORA_NLS32 variable, which defaults from 
ORACLE_HOME. NLSRTL 3.3 files are pointed by the ORA_NLS33 variable, 
which must be set explicitly to $ORACLE_HOME/ocommon/nls/admin/datad2k.

Note3: 
When exporting from the Developer 1.6.1 environment, you might be getting a
ORA-600 [23] [] error. If this is the case, try setting ORA_NLS33 to

  $ORACLE_HOME/ocommon/nls/admin/data 

instead of

  $ORACLE_HOME/ocommon/nls/admin/datad2k 

This should resolve the internal ORA-600 [23][].

6. If ORA_NLSxx is not set or can't be read and the database is started with 
   other languages and character sets, the database will default and character 
   set will not be recognized. 

   This can result in: 

    a. Character set translation not occurring for clients using a character set 
       different from the database's. This may result in corrupt data in certain 
       applications as 8-bit or 16-bit or 32-bit may be lost and misinterpreted. 

    b. ORA-12705 (may be combined with ORA-604 errors).

    c. "SQL*Loader-266: Unable to locate character set" error. 

    d. Messages being displayed in a language different from that expected.
 
    e. ORA-3106 fatal two-task communication protocol error. ORA-600[12333] which 
       will have the same meaning as ORA-3106 in this case. At the client you may
       see a TNS-12571 or ORA-12571.

    You can check which NLS setting are valid for this platform by connecting to 
    the database as a DBA and issuing the following command: 

      SELECT * FROM V$NLS_VALID_VALUES; 

    If this only returns US7ASCII then ORA_NLSxx is INCORRECTLY set.

    To find out what character set you have, issue the following command connected 
    as sys, system or DBA: 

      SELECT * FROM NLS_DATABASE_PARAMETERS;

    Look for the NLS_CHARACTERSET and NLS_NCHAR_CHARACTERSET (from version 8 onwards) parameter.

   you may also  want to check that language files were installed 
   properly on your system. To do that go to directory:

    $ORACLE_HOME/ocommon/nls/admin/data 

   or from 10g onwards:

    $ORACLE_HOME/nls/data

   and issue the following command: 

    strings * | grep -i we8mswin1252

   where we8mswin1252 (or any other than us7ascii) is the character set 
   choosen for the database. 


Solution: 
---------
   set ORA_NLSxx correct and restart the instance (also the service on windows).


7. If ORA_NLSxx is not / wrongly set or can't be read and the listener is started the you will
   typically see that a connection with NLS_LANG *not* set or set to AMERICAN_AMERICA.US7ASCII
   works. But a connection with other territorry and language like DUTCH_BELGIAN.WE8MSWIN1252
   fails with ORA-12705 that is combined with ORA-604. You will see this also when using 
   a 817 listener for a 9i database.

   A ORA-12705 combined with ORA-604 always points to a server problem, database and/or listener started
   with incorrect ORA_NLSxx definition or OS permission problems.


Solution: 
---------
   set ORA_NLSxx correctly and restart the listener (also the service on windows).
   and check file/directory permissions

   We recommend to use a 8i listener for a 8i db, a 9i listener for a 9i db etc...

   If you really want to use a 9i listener for a 8i instance then define the correct
   ORA_NLS33 in the listener.ora like this:

      (SID_DESC =
          (GLOBAL_DBNAME = o8i.oracle.com)
          (ORACLE_HOME = /disk1/oracle8i)
    
    (ENVS='ORACLE_HOME=/disk1/oracle8i,ORA_NLS33=%ORACLE_HOME%/ocommon/nls/admin/data,LD_LIBRARY_PATH=/disk1/oracle8i/lib')
          (SID_NAME = o8i)
        )

   Make sure you disable "automatic listener registration" for the 8i database
   if you use 1521 as listener port.

   8i init.ora
   local_listener="(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=hostname) (PORT=1599)))"

   where 1599 is a port number NOT used by the 9i listener, so that the 8i db is NOT
   able to find the 9i listener.(this has no performance impact)

   Note 130574.1 Disabling Automatic Registration of the Database with the Default Listener

   However then do not forget to start the 9i listener with the 9i settings
   ORACLE_HOME=/disk1/oracle9i
   ORA_NLS33=%ORACLE_HOME%/ocommon/nls/admin/data


8.  If you have only a ORA-12705 alone then the problem is purely on the client side.
    You have a incorrect defined ORA_NLSxx or you have specified a incorrect NLS
    variable on the client side, like NLS_LANG=WE8IOS8859P1 (NLS_LANG=.WE8ISO8859P1 is correct)
    -> see  Note 241047.1 The Priority of NLS Parameters Explained.

Solution: 
---------

     Unix: make sure you use the correct syntax for env variables, remove them for testing if needed 
     we DO recommend to set always ORA_NLSxx, ORACLE_HOME and NLS_LANG correctly in a unix shell env.

     Windows: check the registry key of the oracle_home you are using. Also check for variables
     set in the environment (type "set" in a CMD prompt).
     We do NOT recommend to set Oracle variables in the environment on windows

     Generic: check file/directory permissions

9. OI_NLS32 is a parameter used by the Oracle Universal Installer and should NOT be alterd

See also:
 Note 1058400.6 ORA-12701 When Creating a Database

 Note 241047.1 The Priority of NLS Parameters Explained.

 Note 158577.1 NLS_LANG Explained (How does Client-Server Character Conversion Work?)
    1.2 What is this NLS_LANG thing anyway?
    4.2 How can I Check the Client's NLS_LANG Setting?
 Note 179133.1 The correct NLS_LANG in a Windows Environment
 Note 264157.1How to set correctly NLS_LANG on Unix Environments
 Note 265090.1 How to check Unix terminal Environments for the capability to display extended characters.
 Note 229786.1 NLS_LANG and webservers explained.

 Note 62107.1  The National Character Set in Oracle8
 Note 276914.1 The National Character Set in Oracle 9i and 10g

For further NLS / Globalization information you may start here:
Note 267942.1 Globalization Technology (NLS) Knowledge Browser .