The OPTGUIDELINES element defines the global optimization
guidelines for the optimization profile.
It is defined by the complex type globalOptimizationGuidelinesType.
XML Schema
<xs:complexType name="globalOptimizationGuidelinesType">
<xs:sequence>
<xs:group ref="MQTOptimizationChoices"/>
<xs:group ref="computationalPartitionGroupOptimizationChoices"/>
<xs:group ref="generalRequest"/>
<xs:group ref="mqtEnforcementRequest"/>
</xs:sequence>
</xs:complexType>
Description
Global optimization guidelines
can be defined with elements from the groups MQTOptimizationChoices,
computationalPartitionGroupChoices, or generalRequest.
- MQTOptimizationChoices group elements can be used to influence
MQT substitution.
- computationalPartitionGroupOptimizationChoices group elements
can be used to influence computational partition group optimization,
which involves the dynamic redistribution of data read from remote
data sources. It applies only to partitioned federated database configurations.
- The generalRequest group elements are not specific to a particular
phase of the optimization process, and can be used to change the optimizer's
search space. They can be specified globally or at the statement level.
- MQT enforcement requests specify semantically matchable materialized
query tables (MQTs) whose use in access plans should be enforced regardless
of cost estimates.