Package org.apache.calcite.rel.rules

Class ExchangeRemoveConstantKeysRule

java.lang.Object

org.apache.calcite.plan.RelOptRule

org.apache.calcite.plan.RelRule<ExchangeRemoveConstantKeysRule.Config>

org.apache.calcite.rel.rules.ExchangeRemoveConstantKeysRule

All Implemented Interfaces:

SubstitutionRule, TransformationRule

@Enclosing
public class ExchangeRemoveConstantKeysRule
extends RelRule<ExchangeRemoveConstantKeysRule.Config>
implements SubstitutionRule

Planner rule that removes keys from a Exchange if those keys are known to be constant.

For example, SELECT key,value FROM (SELECT 1 AS key, value FROM src) r DISTRIBUTE BY key can be reduced to SELECT 1 AS key, value FROM src.

See Also:

• CoreRules.EXCHANGE_REMOVE_CONSTANT_KEYS
• CoreRules.SORT_EXCHANGE_REMOVE_CONSTANT_KEYS

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	ExchangeRemoveConstantKeysRule.Config	Rule configuration.

Nested classes/interfaces inherited from class org.apache.calcite.plan.RelRule

RelRule.Done, RelRule.MatchHandler<R extends RelOptRule>, RelRule.OperandBuilder, RelRule.OperandDetailBuilder<R extends RelNode>, RelRule.OperandTransform

Nested classes/interfaces inherited from class org.apache.calcite.plan.RelOptRule

RelOptRule.ConverterRelOptRuleOperand

Field Summary

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

config

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

description, operands, relBuilderFactory

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	ExchangeRemoveConstantKeysRule(ExchangeRemoveConstantKeysRule.Config config)	Creates an ExchangeRemoveConstantKeysRule.

Method Summary

Modifier and Type	Method	Description
void	onMatch(RelOptRuleCall call)	Receives notification about a rule match.
protected static List<Integer>	simplifyDistributionKeys(RelDistribution distribution, Set<Integer> constants)	Removes constant in distribution keys.

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

any, convert, convert, 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

Methods inherited from interface org.apache.calcite.rel.rules.SubstitutionRule

autoPruneOld

Constructor Details

ExchangeRemoveConstantKeysRule

protected ExchangeRemoveConstantKeysRule(ExchangeRemoveConstantKeysRule.Config config)

Creates an ExchangeRemoveConstantKeysRule.

Method Details

simplifyDistributionKeys

protected static List<Integer> simplifyDistributionKeys(RelDistribution distribution,
 Set<Integer> constants)

Removes constant in distribution keys.

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>, org.apache.calcite.plan.RelHintsPropagator) to register the expression.

Specified by:

onMatch in class RelOptRule

Parameters:

call - Rule call

See Also:

• RelOptRule.matches(RelOptRuleCall)