Package org.apache.calcite.rel.rules

Class SingleValuesOptimizationRules.PruneSingleValueRule

java.lang.Object

org.apache.calcite.plan.RelOptRule

org.apache.calcite.plan.RelRule<SingleValuesOptimizationRules.PruneSingleValueRule.Config>

org.apache.calcite.rel.rules.SingleValuesOptimizationRules.PruneSingleValueRule

All Implemented Interfaces:

SubstitutionRule, TransformationRule

Enclosing class:

SingleValuesOptimizationRules

protected abstract static class SingleValuesOptimizationRules.PruneSingleValueRule
extends RelRule<SingleValuesOptimizationRules.PruneSingleValueRule.Config>
implements SubstitutionRule

Abstract class for all the SingleValuesOptimizationRules. All the specific SingleValuesOptimizationRules call the onMatch function to replace a Join with equivalent tree when eligible.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static interface	SingleValuesOptimizationRules.PruneSingleValueRule.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	PruneSingleValueRule(SingleValuesOptimizationRules.PruneSingleValueRule.Config config)

Method Summary

Modifier and Type	Method	Description
boolean	autoPruneOld()	Whether the planner should automatically prune old node when there is at least 1 equivalent rel generated by the rule.
protected BiFunction<RexNode,List<RexNode>,List<RexNode>>	getRexTransformer(RexBuilder rexBuilder, JoinRelType joinRelType)
protected void	onMatch(RelOptRuleCall call, Values values, @Nullable Project project, Join join, RelNode other, boolean isOnLefSide)	onMatch function contains common optimization logic for all the SingleValueOptimization rules.

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, onMatch, 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

Constructor Details

PruneSingleValueRule

protected PruneSingleValueRule(SingleValuesOptimizationRules.PruneSingleValueRule.Config config)

Method Details

getRexTransformer

protected BiFunction<RexNode,List<RexNode>,List<RexNode>> getRexTransformer(RexBuilder rexBuilder,
 JoinRelType joinRelType)

onMatch

protected void onMatch(RelOptRuleCall call,
 Values values,
 @Nullable Project project,
 Join join,
 RelNode other,
 boolean isOnLefSide)

onMatch function contains common optimization logic for all the SingleValueOptimization rules. It simplifies the rel node tree by removing a Join node and creating a required filter as applicable. In case of the LEFT/RIGHT joins, a case expression which produce NULL values for non-matching rows will be created as part of a Project node. The transformation can be illustrated by following e.g. TableScan(Emp) join (cond: Emp.empno = v.no) with Values(1010 as no) → Filter(Emp.empno = 1010) on TableScan(Emp)

Parameters:

call - A RelOptRuleCall object

values - A constant relation node which produces a single row.

project - A project node which has dynamic constants (can be null).

join - A join node which will get removed.

other - A node on the other side of the join (apart from Values)

isOnLefSide - Whether a Values node is on the Left side or the right side of the Join.

autoPruneOld

public boolean autoPruneOld()

Description copied from interface: SubstitutionRule

Whether the planner should automatically prune old node when there is at least 1 equivalent rel generated by the rule.

Default is false, the user needs to prune the old node manually in the rule.

Specified by:

autoPruneOld in interface SubstitutionRule