onmode -D, -M, -Q, -S: Change decision-support parameters

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Syntax:

>>-onmode--+- -D--max_priority-+-------------------------------><
           +- -M--kilobytes----+   
           +- -Q--queries------+   
           '- -S--scans--------'   

Element Purpose Key considerations
-D max_priority Changes the value of MAX_PDQPRIORITY This value must be an unsigned integer between 0 and 100.

Specify max_priority as a factor to temper user requests for PDQ resources.

For information on parameters used for controlling PDQ, see MAX_PDQPRIORITY configuration parameter and the IBM® Informix Performance Guide.

-M kilobytes Changes the value of DS_TOTAL_MEMORY This value has a platform-dependent upper limit. If you enter a very large value and that value is too large for your platform, you will receive a message that gives you the range of values for your platform.

Specify kilobytes for the maximum amount of memory available for parallel queries.

For more information, see DS_TOTAL_MEMORY configuration parameter and the IBM Informix Performance Guide.

-Q queries Changes the value of DS_MAX_QUERIES This value must be an unsigned integer between 1 and 8,388,608.

Specify queries for the maximum number of concurrently executing parallel queries.

For information on parameters used for controlling PDQ, see DS_MAX_QUERIES configuration parameter and the IBM Informix Performance Guide.

-S scans Changes the value of DS_MAX_SCANS This value must be an unsigned integer between 10 and 1,048,576.

Specify scans for the maximum number of concurrently executing parallel scans.

For information on parameters used for controlling PDQ, see DS_MAX_SCANS configuration parameter and the IBM Informix Performance Guide.

These options allow you to change configuration parameters while the database server is online. The new values affect only the current instance of the database server; the values are not recorded in the ONCONFIG file. If you shut down and restart the database server, the values of the parameters revert to the values in the ONCONFIG file. For more information about these configuration parameters, see Database configuration parameters.

To check the current values for the MAX_PDQPRIORITY, DS_TOTAL_MEMORY, DS_MAX_SCANS, DS_MAX_QUERIES, and the DS_NONPDQ_QUERY_MEM configuration parameters, use onstat -g mgm. See onstat -g mgm command: Print MGM resource information.

This command has an equivalent SQL administration API function.


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