Configuring Worker Processes

The max worker processes, number of worker processes, and memory per worker process configuration parameters affect dbcc checkstorage.

max worker processes specifies the maximum number of worker processes used by dbcc checkstorage for each target database, while number of worker processes specifies the total number of worker processes supported by SAP ASE. Worker processes are not dedicated to running dbcc checkstorage operations.

Set the value for number of worker processes high enough to allow for the number of processes specified by max worker processes. A low number of worker processes reduces the performance and resource consumption of dbcc checkstorage. dbcc checkstorage cannot use more processes than the number of database devices used by the database. Cache size, CPU performance, and device sizes might suggest a lower worker processes count. If there are not enough worker processes configured for SAP ASE, dbcc checkstorage does not run.

maximum parallel degree and maximum scan parallel degree have no effect on the parallel functions of dbcc checkstorage. When maximum parallel degree is set to 1, parallelism in dbcc checkstorage is not disabled.

dbcc checkstorage requires multiple processes, so number of worker processes must be set to at least 1 to allow for a parent process and a worker process.

sp_plan_dbccdb recommends values for the number of worker processes, depending on database size, number of devices, and other factors. You can use smaller values to limit the load on your system. dbcc checkstorage may use fewer worker processes than sp_plan_dbccdb recommends, or fewer than you configure.

Using more worker processes does not guarantee faster performance. The following scenario describes the effects of two different configurations:

memory per worker process specifies the total memory allocation for worker processes support in SAP ASE. The default value is adequate for dbcc checkstorage.