Some Unicode support is available at ArcSDE 9.0 and 9.1 when using Oracle or DB2 databases with character set UTF8, but with limitations. For example, it is not possible to load and display attributes in multiple languages in the same feature class.
For multilingual Unicode support, ArcSDE 9.0 and 9.1 support NCHAR and NVARCHAR columns in the database. NCHAR and NVARCHAR use UTF16 character encoding. To access and update these columns, use SDE C API calls, SE_stream_set_nstring(), and SE_stream_get_nstring().
Note: ArcGIS Desktop has not implemented support for NCHAR and NVARCHAR; Therefore, when using ArcGIS Desktop with ArcSDE, there is no support for NCHAR and NVARCHAR.
The following information describes database-specific Unicode limitations in ArcSDE 9.0 and 9.1:
If an Oracle database is created with character set UTF8, CHAR and VARCHAR can store characters in UTF8. However, only one language can be loaded or displayed at a time. To load or display different languages, set the appropriate NLS_LANG value for each language before attempting to load or display each language, one at a time.
▪ SQL Server
CHAR and VARCHAR are non-Unicode data types in SQL Server. Unicode data is stored using the NCHAR and NVARCHAR data types in SQL Server. However, as stated above, ArcGIS Desktop does not support NCHAR and NVARCHAR, so when using ArcGIS Desktop with ArcSDE, there is no support for NCHAR and NVARCHAR.