Job DSNTIJUZ and the subsystem parameter load module, application defaults load module, and DSNHMCID

Job DSNTIJUZ generates the subsystem parameter module each time that you install, migrate, or update DB2®. Start of change DSNTIJUZ also creates the application defaults load module and DSNHMCID. End of change

Several macros expand to form the data-only subsystem parameter load module, which contains the DB2 execution-time parameters that you selected using the ISPF panels. The macros are:

DSN6ARVP
DSN6FAC
DSN6LOGP
DSN6SPRM
DSN6SYSP
DSN6GRP

Start of change Job DSNTIJUZ also generates the application defaults load module (referred to here as dsnhdecp with either the traditional name of DSNHDECP or a user-specified name. DB2 is shipped with a default dsnhdecp module called DSNHDECP for compatibility with older applications. You cannot start DB2 or precompile applications with the default dsnhdecp module. During DB2 start-up processing or for jobs that precompile a DB2 application, you must ensure that the dsnhdecp module that was created by job DSNTIJUZ resides in a library, usually prefix.SDSNEXIT, that is concatenated before the prefix.SDSNLOAD library where the DB2-supplied dsnhdecp resides. End of change

Job DSNTIJUZ also creates the data-only load module DSNHMCID, which contains the EBCDIC CCSIDs for text conversion in offline messages. When you install DB2, job DSNTIJUZ creates DSNHMCID in prefix.SDSNEXIT and prefix.SDSNLOAD.

In general, DSNHMCID should exist in both prefix.SDSNEXIT and prefix.SDSNLOAD. If it cannot reside in prefix.SDSNLOAD, take one of the following actions:

Include prefix.SDSNEXIT before prefix.SDSNLOAD in the system link list.
Include prefix.SDSNEXIT before prefix.SDSNLOAD in the JOBLIB or STEPLIB statements for all DB2 applications, address space start-up procedures, TSO log-on procedures, CICS® tasks, and IMS™ tasks that use DB2.

DB2 allows online changes to many of the subsystem parameters. The SET SYSPARM command enables a function that allows reloading.