BOUND_IMPL_PDQ Environment Option (XPS)

If IMPLICIT_PDQ is set to ON or to a value, use the BOUND_IMPL_PDQ environment option to specify that the allocated memory should be bounded by the current explicit PDQPRIORITY value or range. If IMPLICIT_PDQ is OFF, then BOUND_IMPL_PDQ is ignored. For example, you might execute the following statement to force the database server to use explicit PDQPRIORITY values as guidelines in allocating memory if the IMPLICIT_PDQ environment option has already been set:

SET ENVIRONMENT BOUND_IMPL_PDQ ON

If you set both IMPLICIT_PDQ and BOUND_IMPL_PDQ, then the explicit PDQPRIORITY value determines the upper limit of memory that can be allocated to a query. If PDQPRIORITY is specified as a range, the database server grants memory within the range specified.

For detailed information, see the IBM Informix Performance Guide.