IBM is setting up a table, ODSCRT, that is an application/applicationgroup/storage node cross reference. We have a rotation across 4 OAM databases in one instance, and 3 OAM databases in the other. We have multiple versions of each report, and in V2, change the active version depending where we want to write. When a database's contents has all gone out to tape, we re-org it in place down to one volume, then set the version that writes to it as current. With one set, that is yearly. With another it is about every 13 weeks. This keeps our space under control.
In version 8, we'll need to update the ODSCRT table to identify which is the active version. Ask IBM about the implementation of this table with CMOD 7.1/8.4. They have a patch to ARSLOAD so that it checks this table to determine which node to write to for a given application group and application combination.
I hope to have some jobs that monitor the row count in the pertinent OAM tables, and auto-update ODSCRT as appropriate, but we'll be creating them ourselves. Since we are already doing this, IBM has to take it into account as part of our migration scenario.