Number of tasks

Specify the number of tasks to be used when the query optimizer chooses to use SMP parallel processing to process a query. I/O parallelism is also allowed. SMP parallel processing is used only if the system feature, DB2 Symmetric Multiprocessing, is installed.

Using a number of tasks less than the number of processors available on the system restricts the number of processors used simultaneously for running a given query or database file keyed access path build, rebuild, or maintenance. A larger number of tasks ensures that the query or database file keyed access path build, rebuild, or maintenance is allowed to use all of the processors available on the system to run the query. Too many tasks can degrade performance because of the over-commitment of active memory and the overhead cost of managing all of the tasks.