Package org.apache.calcite.rel.rules

Class AggregateProjectPullUpConstantsRule

java.lang.Object

org.apache.calcite.plan.RelOptRule

org.apache.calcite.rel.rules.AggregateProjectPullUpConstantsRule

public class AggregateProjectPullUpConstantsRule
extends RelOptRule

Planner rule that removes constant keys from an Aggregate.

Constant fields are deduced using RelMetadataQuery.getPulledUpPredicates(RelNode); the input does not need to be a Project.

This rules never removes the last column, because Aggregate([]) returns 1 row even if its input is empty.

Since the transformed relational expression has to match the original relational expression, the constants are placed in a projection above the reduced aggregate. If those constants are not used, another rule will remove them from the project.

Field Summary

Fields

Modifier and Type	Field	Description
static AggregateProjectPullUpConstantsRule	INSTANCE	The singleton.
static AggregateProjectPullUpConstantsRule	INSTANCE2	More general instance that matches any relational expression.

Fields inherited from class org.apache.calcite.plan.RelOptRule

description, operands, relBuilderFactory

Constructor Summary

Constructors

Constructor	Description
AggregateProjectPullUpConstantsRule(java.lang.Class<? extends Aggregate> aggregateClass, java.lang.Class<? extends RelNode> inputClass, RelBuilderFactory relBuilderFactory, java.lang.String description)	Creates an AggregateProjectPullUpConstantsRule.

Method Summary

Modifier and Type	Method	Description
void	onMatch(RelOptRuleCall call)	Receives notification about a rule match.

Methods inherited from class org.apache.calcite.plan.RelOptRule

any, convert, convert, convertList, convertOperand, convertOperand, equals, equals, getOperand, getOperands, getOutConvention, getOutTrait, hashCode, matches, none, operand, operand, operand, operand, operand, operandJ, operandJ, some, toString, unordered

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

INSTANCE

public static final AggregateProjectPullUpConstantsRule INSTANCE

The singleton.

INSTANCE2

public static final AggregateProjectPullUpConstantsRule INSTANCE2

More general instance that matches any relational expression.

Constructor Detail

AggregateProjectPullUpConstantsRule

public AggregateProjectPullUpConstantsRule(java.lang.Class<? extends Aggregate> aggregateClass,
                                           java.lang.Class<? extends RelNode> inputClass,
                                           RelBuilderFactory relBuilderFactory,
                                           java.lang.String description)

Creates an AggregateProjectPullUpConstantsRule.

Parameters:

aggregateClass - Aggregate class

inputClass - Input class, such as LogicalProject

relBuilderFactory - Builder for relational expressions

description - Description, or null to guess description

Method Detail

onMatch

public void onMatch(RelOptRuleCall call)

Description copied from class: RelOptRule

Receives notification about a rule match. At the time that this method is called, call.rels holds the set of relational expressions which match the operands to the rule; call.rels[0] is the root expression.

Typically a rule would check that the nodes are valid matches, creates a new expression, then calls back RelOptRuleCall.transformTo(org.apache.calcite.rel.RelNode, java.util.Map<org.apache.calcite.rel.RelNode, org.apache.calcite.rel.RelNode>) to register the expression.

Specified by:

onMatch in class RelOptRule

Parameters:

call - Rule call

See Also:

RelOptRule.matches(RelOptRuleCall)