The UseSYSDUMMYAEU parameter affects how LOB data is processed on a DB2 for z/OS host. The default setting of Yes indicates that the DB2 for z/OS system catalog contains the system tables SYSDUMMYA, SYSDUMMYE, and SYSDUMMYU, and StarSQL will use these tables instead of the standard SYSDUMMY1 table to avoid unnecessary conversion of LOB data that has a CCSID associated with it.
The SYSDUMMYA, SYSDUMMYE, and SYSDUMMYU tables are created by applying PTFs that IBM made available in APAR PQ85495. You can verify whether these tables exist on the host by entering the following statement:
SELECT * FROM SYSIBM.SYSTABLES WHERE NAME LIKE ‘SYSDUMMY%’
Note that only the SYSDUMMYA and SYSDUMMYE tables are created when applying the PTF to DB2 for z/OS v6—the SYSDUMMYU table is not created for that version. If your system has only the standard SYSDUMMY1 table and your database contains LOB data, the following error may be returned at runtime when users try to access LOB data:
SQLSTATE 42704 (-204) “[StarSQL][StarSQL ODBC Driver][DB2] IS AN UNDEFINED NAME”
To resolve this error you can:
set the UseSYSDUMMYAEU keyword to No, or
apply the PTFs from IBM APAR PQ85495 (http://www-1.ibm.com/support/docview.wss?uid=swg1PQ85495) to create the new SYSDUMMY tables.
If you set the UseSYSDUMMYAEU keyword to No, any double-byte EBCDIC or ASCII GRAPHIC data will be converted to UNICODE on the host before it is sent to StarSQL. If host performance is an issue, apply the PTFs and set UseSYSDUMMYAEU to Yes to avoid the unnecessary conversion.