When displaying characters on your terminal display, the default CCSID values for an application requester must be compatible with the code page that was used to generate its terminal controller. If the defaults are incompatible, characters will not be displayed or interpreted as expected, and the results of queries or inserts of either character or graphic data will be unreliable. Table 21 and Table 22 show the code pages that are compatible with each CCSID, and the CHARNAME value that you should specify. For example, if the controller was generated with code page 37, you should specify ENGLISH for the CHARNAME parameter. This value sets the value of CCSIDSBCS to 37, and the values of CCSIDMIXED and CCSIDGRAPHIC to 0. You can use the SQLGLOB EXEC to set default values for all application requesters. For more information, see Setting the Default CHARNAME and CCSIDs for All Application Requesters . The system-wide defaults may not be suitable for all application requesters: some may have a controller generated to use a code page incompatible with the system-wide default CHARNAME. In this situation, you should set the CHARNAME parameter for individual application requesters. For more information on this topic, see Setting the Application Requester Default CHARNAME and CCSIDs.
The default CCSID values for the application server can be set to any value you want, but keep in mind that you may want to set the default CCSIDs for the application server to values that can be used as defaults by the majority of the application requesters. This can reduce the amount of CCSID conversion that will be necessary.
In particular, the CHARNAME INTERNATIONAL (CCSID=500) warrants special attention. This CHARNAME is composed of a code page that supports all the characters that are supported by the Latin-1 countries, including Australia, Austria, Belgium, Brazil, Denmark, Canada, the Faroe Islands, Finland, France, Germany, Hong Kong, Iceland, Italy, Japan, the Netherlands, New Zealand, Norway, Portugal, Spain, Latin America, Sweden, Switzerland, the United Kingdom, and the United States. If all application requesters and application servers in these countries use this CCSID, then single-byte CCSID conversion will not be necessary for accessing data from different sites. This may provide savings because of lower CPU usage.
Often, it may not be appropriate to use CCSID 500 at every site. For example, you may have to use existing equipment (such as terminal controllers that use other character sets and code pages), or you may have a large quantity of data that is stored using a CCSID other than 500. However, if you plan to frequently access data from other countries, you should consider migrating your data and hardware to CCSID 500, both for performance reasons, and for the ease of data management.