CICS VSAM Transparency for z/OS, Version 1.2


MULTFBE variations

MULTFBE retrieves a single row from the appropriate table. When a group OCCURS field is migrated to multiple rows, the FBE uses a cursor to retrieve all of the DB2® rows to build the group OCCURS fields. An SQL code +100 is returned when all rows have been fetched.

If your IRD is checking for updates to the group field, your FBE must store the group field data when a get-for-update call is processed. EXCALL = GETU in this case. This technique is described in Exit work area.

Initial data migration to multiple tables

You use the VIDLOAD utility to convert the VSAM records into the appropriate format for loading into DB2. When you are migrating to multiple DB2 tables using a combination of an FBE and an IRD, you must specify the output DD statement LOADOUTM. An example of the JCL is shown in Figure 1.

Loading large tables

When a VSAM file is migrated to multiple DB2 tables, you use the LOADOUTM DD statement in the VIDLOAD utility. The output sequential data set contains records for all the tables associated with the file, and you must use the WHEN statement in the DB2 load utility control cards.

The DB2 load utility reads every record in the input sequential data set to satisfy the WHEN statement. If you are migrating a very large VSAM file, it is often more efficient to split the VIDLOAD output file into a separate data set for each table. You can achieve this with DFSORT, like the example in Figure 1.



Concept topic


Last updated: May 25, 2012 20:46:4