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How To: Disable Unicode storage in an ArcSDE for Oracle geodatabase

Summary

Beginning with ArcSDE 9.2, a DBTUNE parameter (UNICODE_STRING) was added to ArcSDE geodatabases in Oracle to control the storage of string data. If this parameter is set to TRUE, character fields are stored in a UNICODE compliant data type. In Oracle, that field type is NVARCHAR2. By default, string data stored in an ArcSDE 9.2 or later release geodatabase in Oracle are stored as NVARCHAR2.

If the UNICODE_STRING parameter is set to FALSE, string data types are stored as VARCHAR2 in Oracle.

If UNICODE characters are not required in the geodatabase, set the UNICODE_STRING parameter under the DEFAULTS keyword in the DBTUNE table to FALSE.

Procedure

To disable UNICODE character encoding, add the UNICODE_STRING parameter to the DEFAULTS keyword in the DBTUNE table and set it to FALSE. This can be done using the sdedbtune command.

Note:
Close other connections to the geodatabase before proceeding with the following tasks.

  1. Use the sdedbtune -o export command to export the contents of the DBTUNE table to a text file.

    Code:
    sdedbtune -o export -f C:\temp\dbtune.sde
    -s sung2 -i 6363 -u sde -p sde
    ArcSDE 9.2 for Oracle10g Build 1239 Thu Jan 24 09:35:02 2008
    Attribute Administration Utility
    -----------------------------------------------------

    Successfully exported to file "C:\temp\dbtune.sde" on server sung2

  2. Navigate to where the contents were exported and open the file in a text editor.
  3. Add the following line to the DEFAULTS keyword in the dbtune.sde file:

    Code:
    UNICODE_STRING "FALSE"

  4. Import the altered dbtune.sde file back into the ArcSDE geodatabase.

    Note:
    Only an ArcSDE administrator can import the dbtune.sde file into the geodatabase.


    Code:
    sdedbtune -o import -f C:\temp\dbtune.sde
    -s sung2 -i 6363 -u sde -p sde
    ArcSDE 9.2 for Oracle10g Build 1239 Thu Jan 24 09:35:02 2008
    Attribute Administration Utility
    -----------------------------------------------------
    Import DBTUNE Table. Are you sure? (Y/N): y

    Successfully imported from file "C:\temp\dbtune.sde"

  5. To be sure this worked, create a new feature class in ArcCatalog. Be sure to add a field that is data type 'Text'. Describe the feature class in SQL Plus.

    In this example, the Text field in the feature class is named Test.

    Code:
    SQL> desc test_text;

    Name Null? Type
    ----------------------------------------- -------- ---------------------

    OBJECTID NOT NULL NUMBER(38)
    TEST VARCHAR2(50)
    SHAPE ST_GEOMETRY