DB2 Server for VSE: System Administration

Step 6: Update the SYSTEM.SYSSTRINGS Catalog Table

The SYSTEM.SYSSTRINGS catalog table identifies the tables that will be used for conversion between specific pairs of CCSIDs. Conversion tables for CDRA-supplied CCSIDs are provided by the CDRA registry. For more information on CDRA conversion tables, see the Character Data Representation Architecture Level 1, Registry manual. After you create your CCSID, you must determine the conversion table information for SYSTEM.SYSSTRINGS. You must add a row to SYSTEM.SYSSTRINGS for each conversion that you want to support both to and from the new CCSID. For a detailed description to update SYSTEM.SYSSTRINGS, see Appendix D, Updating SYSTEM.SYSSTRINGS.

Suppose you added CCSID 57344 and you want to support the following conversions:

• CCSID 37 to CCSID 57344
• CCSID 57344 to CCSID 37
• CCSID 57344 to CCSID 28709.

You must add three rows to the SYSTEM.SYSSTRINGS catalog table. To specify any of these conversions in SYSTEM.SYSSTRINGS, you would use an INSERT statement to insert the necessary information into the following columns of the catalog table:

• INCCSID, which specifies the CCSID of the input character.
• OUTCCSID, which specifies the CCSID to which the conversion is done.
• TRANSTYPE, which identifies the type of conversion to be done (for example, 'SS' for SBCS to SBCS).
• ERRORBYTE, which identifies characters that have no representation in the target code page. If a character to be converted maps to a code point containing this byte an error occurs.
• SUBBYTE, which identifies characters that have no representation in the target code page. If a character to be converted maps to a code point identified by this byte, a warning is issued.
• TRANSPROC, which identifies the conversion procedures that are used for conversion between CCSIDs. The procedures are used either for converting between DBCS CCSIDs, or for converting the DBCS components of mixed CCSIDs. The TRANSPROC value is blank if a DBCS conversion procedure is not applied. For more information, see Coding Your Own TRANSPROC Exit.
• TRANSTAB1, which represents the first 64 bytes of the conversion table.
• TRANSTAB2, which represents the last 192 bytes of the conversion table.

The conversion table maps the hexadecimal representation of each character in the source CCSID to the hexadecimal representation of each character in the target CCSID. For example, in CCSID 37 an exclamation mark (!) is represented by X'5A'. The hexadecimal representation for the exclamation mark in CCSID 281 is X'4F'. The hexadecimal value of the character at offset 90 in the conversion table where INCCSID=37 and OUTCCSID=281 would be X'4F'. Remember, when counting offsets, the first offset is zero. Therefore, the byte at offset 90 is actually the 91st.

For a detailed description to update SYSTEM.SYSSTRINGS, see Appendix D, Updating SYSTEM.SYSSTRINGS.

When you have completed steps 1 through 6, you can start the application server using the newly defined character set. If the database manager detects an error in the character set, it uses the value of CHARNAME that was used the last time the application server was started.