z/VSE JCL example 2: VSAM-managed sequential files

Figure 1 shows simplified z/VSE JCL for comparing two VSAM-managed sequential files. This example is supplied with SuperC in the Librarian member ASMFVSC2.Z.

Figure 1. Sample z/VSE JCL for comparing VSAM-managed sequential files

// JOB ASMFVSC2
// LIBDEF *,SEARCH=(PRD2.PROD)
// OPTION NODUMP
// DLBL NEWDD,'new_file_ID',0,VSAM,DISP=(OLD,KEEP)
// DLBL OLDDD,'old_file_ID',0,VSAM,DISP=(OLD,KEEP)
// DLBL UPDDD,'update_file_ID',0,SD
// EXTENT extent_information
// ASSGN assign_logical_unit_information
// EXEC ASMFSUPC,PARM='options'
process_statements
⋮
/*
/&

The update file, which is created by SuperC only if you specify an "UPD…" process option, is a non-VSAM-managed sequential file.

If you want to use DLBL names other than NEWDD, OLDDD, and UPDDD, then you must specify NEWDD, OLDDD, and UPDDD process statements (as shown in Figure 1).

If you specify file attributes with the NEWDD and OLDDD process statements, then those file attributes override the VSAM catalog entries for the new and old files.