DB2 Server for VM: System Administration

Choosing the Default CHARNAME and CCSID for Application Requesters

It is important that the appropriate application requester default CHARNAME and appropriate application requester default CCSID be chosen. The goals of choosing the correct values are to ensure the integrity of character data representation, and to reduce the performance overhead associated with CCSID conversion.

For example, if your terminal controller is generated with code page 37 and character set 697 (CP/CS 37/697) for US ENGLISH characters, then the application requester should set the default CHARNAME to ENGLISH. This is because CP/CS 37/697 corresponds to the CCSID of 37 which corresponds to the CHARNAME of ENGLISH.

The application requester default CCSID is the value of CCSIDMIXED if it is not zero; otherwise, it is the value of CCSIDSBCS. The application requester default CCSID is used for the following:

• The CCSID of SQL statements coded at the application requester
• The CCSID of host variables which represent character data
• The CCSID of character values described by an input or output SQLDA (when the SQLNAME field is not used to override the CCSID value)
• The CCSID of character data returned in a DESCRIBE SQLDA
• The CCSID of message tokens returned in an SQLCA

For more information on setting the default CHARNAME for an application requester, see Setting the Default CHARNAME and CCSIDs for an Application Requester. For more information on CCSIDs, see CCSID Conversion and Determining CCSID Values.

You can avoid the need for all application requesters to specify the default CHARNAME by setting it using the SQLGLOB EXEC. For information on setting the default CHARNAME for all application requesters, see Setting the Default CHARNAME and CCSIDs for All Application Requesters.