MAXTASKS control statement
The MAXTASKS control statement is used to customize the IMS Index Builder run.
This parameter allows you to control the number of subordinate address spaces (SAS) created. When using the low values range (0, 1, 2), MAXTASKS allows you to pre-determine the scan and sort modes. In default mode, without MAXTASKS specified, IMS Index Builder will select the scan and sort modes, and create the subordinate address spaces that are needed to efficiently process your request. While default mode is generally recommended, you might want to use MAXTASKS instead of the default mode to improve efficiency, or use MAXTASKS after a failure as an alternative approach. MAXTASKS takes effect only when secondary indexes are rebuilt.
When the MAXTASKS statement is specified, IMS Index Builder creates less than or equal to the number of subordinate address spaces that are specified. Two thirds of the subordinate address spaces that are created are allocated to scan. Valid values are 0 - 36, with leading zeros. The maximum field length is 15 characters.
If MAXTASKS 0 is specified, all processing occurs in the master address space using striped sorts. If MAXTASKS 2 is specified, the hierarchical HPU scan is selected and subordinate address spaces are created for buffered sorts.
- MAXTASKS
- Specifies that this is a MAXTASKS statement.
- nn
- Valid values are 0 - 36, with leading zeros. Do not specify MAXTASKS 1.
- PSORT
- Enables the parallel sort for a PSINDEX so that the partitions are sorted in parallel. This sort type can improve the performance of building a PSINDEX by starting a buffered sort for each PSINDEX partition and by loading the index records in the E35 sort exit.