DS_MAX_QUERIES configuration parameter

Use the DS_MAX_QUERIES configuration parameter to specify the maximum number of parallel database queries (PDQ) that can run concurrently.

The value of the DS_MAX_QUERIES configuration parameter is dependent on the setting for the DS_TOTAL_MEMORY configuration parameter:
  • If the DS_TOTAL_MEMORY configuration parameter is set, then the value of the DS_MAX_QUERIES is DS_TOTAL_MEMORY / 128, rounded down to the nearest integer value.
  • If the DS_TOTAL_MEMORY configuration parameter is not set, then the value of the DS_MAX_QUERIES configuration parameter is 2 * num, where num is the number of CPUs specified in the VPCLASS configuration parameter.
onconfig.std value
Not set.
if not present
2* num * 128, where num is the number of CPUs specified in the VPCLASS configuration parameter.
values
Minimum value = 1
Maximum value = 8,388,608 (8 megabytes)
units
Number of queries
takes effect
After you edit your onconfig file and restart the database server.
When you reset the value dynamically in your onconfig file by running the onmode -wf command.
When you reset the value in memory by running the onmode -wm command.

Usage

The Memory Grant Manager (MGM) reserves memory for a query based on the following formula:
memory_reserved = DS_TOTAL_MEMORY *
                    (PDQ-priority / 100) *
                 (MAX_PDQPRIORITY / 100)

The value of PDQPRIORITY is specified in either the PDQPRIORITY environment variable or the SQL statement SET PDQPRIORITY.


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