This parameter controls the priority given both to all agents, and to other database manager instance processes and threads, by the operating system scheduler. In a partitioned database environment, this also includes both coordinating and parallel agents, the parallel system controllers, and the FCM daemons. This priority determines how CPU time is given to the DB2 processes, agents, and threads relative to the other processes and threads running on the machine. When the parameter is set to -1, no special action is taken and the database manager is scheduled in the normal way that the operating system schedules all processes and threads. When the parameter is set to a value other than -1, the database manager will create its processes and threads with a static priority set to the value of the parameter. Therefore, this parameter allows you to control the priority with which the database manager processes and threads will execute on your machine.
You can use this parameter to increase database manager throughput. The values for setting this parameter are dependent on the operating system on which the database manager is running. For example, in a UNIX-based environment, numerically low values yield high priorities. When the parameter is set to a value between 41 and 125, the database manager creates its agents with a UNIX static priority set to the value of the parameter. This is important in UNIX-based environments because numerically low values yield high priorities for the database manager, but other processes (including applications and users) may experience delays because they cannot obtain enough CPU time. You should balance the setting of this parameter with the other activity expected on the machine.
In an OS/2 environment, higher numeric values yield higher priorities.
Recommendation: The default value should be used initially. This value provides a good compromise between response time to other users/applications and database manager throughput.
If database performance is a concern, you can use benchmarking techniques to determine the optimum setting for this parameter. You should take care when increasing the priority of the database manager because performance of other user processes can be severely degraded especially when the CPU utilization is very high. Increasing the priority of the database manager processes and threads can have significant performance benefits.
| Note: | If you set this parameter to a non-default value on UNIX-based platforms, you cannot use the governor to alter agent priorities. |