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We have four DB2 subsystems in one OS/390 logical partition (LPAR). Until now, we didn't need to share data between the four subsystems. We'll now migrate to DB2 (from another DBMS), and the database is needed in batch jobs for read-only purposes. Do you see DDF as an option for sharing data in the scenario I described?

Robert Catterall responds:

From a tactical perspective, DDF could be a good move for you. DRDA support for three-part table names, combined with the use of aliases, could make it appear to programs that the data is local to the subsystem, regardless of where it's actually located. That is to say, the data could be part of a database on DB2 subsystem A, but a program running on subsystem B would access the data as though it were stored in the local database. Remote access via DDF would be transparent to programs. You would have to choose one of the four subsystems as the home of the data. I'd recommend choosing the subsystem that you expect will have the highest volume of data accesses.

Why are there four subsystems running in one LPAR? Merging these into one would take some effort, but it would likely yield some manageability benefits. You might want to consider doing that if you anticipate more of these shared data requirements popping up.

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