The old DB2 Precompiler services did not know about or handle CCSID values for host variables. Because of this lack of knowledge, you could update FOR BIT DATA columns with CHARACTER data.
The new DB2 V7.1 or later DB2 Precompiler services does know about CCSID values and will assign them to host variables using the default CCSID value. This will cause problems if you have code that updates FOR BIT DATA columns with CHARACTER data. The integrated PL/I SQL preprocessor has created a new option, CCSID0 / NOCCSID0 to handle these cases. The CCSID0 option, the default, will cause a CCSID of 0 to be assigned to host variables allowing the assignment of CHARACTER variables to FOR BIT DATA database columns.
For more information about the integrated PL/I SQL preprocessor, refer to the Enterprise PL/I for z/OS Programming Guide.