Controlling resources allocated to PDQ

To control resources allocated to PDQ, you can set the PDQPRIORITY environment variable. The queries that do not set the PDQPRIORITY environment variable before they issue a query do not use PDQ. In addition, to place a ceiling on user-specified PDQ priority levels, you can set the MAX_PDQPRIORITY configuration parameter.

When you set the PDQPRIORITY environment variable and MAX_PDQPRIORITY parameter, you exert control over the resources that the database server allocates between OLTP and DSS applications. For example, if OLTP processing is particularly heavy during a certain period of the day, you might want to set MAX_PDQPRIORITY to 0. This configuration parameter puts a ceiling on the resources requested by users who use the PDQPRIORITY environment variable, so PDQ is turned off until you reset MAX_PDQPRIORITY to a nonzero value.