4. Enter  6  and press Enter. A window similar to the window that is shown in Figure 10-6  opens. Db2 subsystems that cannot be selected because they are not enabled for  incremental updates are listed. Under “Select a database system”, you see the Db2  subsystems that you can select. 5. Enter the number of the Db2 subsystem that you want to enable and press Enter. The  message that is shown in Figure 10-7 is displayed. The performance measurement used as many as 500 IBM Retail Data Warehouse  LINEITEM-like tables to simulate the customer’s use case. Each table includes approximately  24 million rows and is in a partition by range table space. Concurrent insert and update  transactions were run against these 500 tables. The measurement is to compare the  replication throughput of a single apply to multiple apply with a default of four parallel apply  threads.  The measurements showed up to 98% replication throughput improvement comparing  parallel apply by using four threads to apply by using a single thread.  Chapter 10. IBM Db2 Analytics Accelerator for z/OS 309 Performance results Performance measurement Figure 10-7 Enabling the feature prompt Figure 10-6 Available Db2 subsystems