Automatic load considerations for z/OS

Setting the NUMTCB parameter

The Q Apply program uses the LOAD from CURSOR utility to perform automatic loading of target tables on z/OS. To invoke the utility, the Q Apply program calls the DSNUTILS stored procedure that is shipped with DB2® for z/OS.

DSNUTILS must run in a Work Load Manager (WLM) environment. You must set the NUMTCB parameter, which is used to start WLM, as follows:

NUMTCB=1

For more detail on DSNUTILS, see the DB2 for z/OS Utility Guide and Reference for your version.

Table space considerations for parallel loads

On z/OS, if you activate multiple Q subscriptions at the same time and the Q Apply program is performing an automatic load of target tables, the Q Apply program will load the target tables in parallel. In this case, you must ensure that each target table is in a separate table space.

An alternative to putting each target table in a separate table space is to start each Q subscription sequentially so that the load for one Q subscription finishes before the load for the next Q subscription begins.

To avoid a parallel load:

1. Start the first Q subscription.
2. Wait for the Q subscription state to change to A (active).

   You can verify the Q subscription state by using the Manage Q Subscriptions window in the Replication Center, or looking at the STATE column of the IBMQREP_TARGETS control table.

3. Activate the next Q subscription.