Package org.apache.calcite.rel.rules

Class ReduceExpressionsRule.FilterReduceExpressionsRule

java.lang.Object

org.apache.calcite.plan.RelOptRule

org.apache.calcite.plan.RelRule<C>

org.apache.calcite.rel.rules.ReduceExpressionsRule<ReduceExpressionsRule.FilterReduceExpressionsRule.FilterReduceExpressionsRuleConfig>

org.apache.calcite.rel.rules.ReduceExpressionsRule.FilterReduceExpressionsRule

All Implemented Interfaces:

SubstitutionRule, TransformationRule

Enclosing class:

ReduceExpressionsRule<C extends ReduceExpressionsRule.Config>

public static class ReduceExpressionsRule.FilterReduceExpressionsRule
extends ReduceExpressionsRule<ReduceExpressionsRule.FilterReduceExpressionsRule.FilterReduceExpressionsRuleConfig>

Rule that reduces constants inside a Filter. If the condition is a constant, the filter is removed (if TRUE) or replaced with an empty Values (if FALSE or NULL).

See Also:

• CoreRules.FILTER_REDUCE_EXPRESSIONS

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	ReduceExpressionsRule.FilterReduceExpressionsRule.FilterReduceExpressionsRuleConfig	Rule configuration.

Nested classes/interfaces inherited from class org.apache.calcite.rel.rules.ReduceExpressionsRule

ReduceExpressionsRule.CalcReduceExpressionsRule, ReduceExpressionsRule.CaseShuttle, ReduceExpressionsRule.Config, ReduceExpressionsRule.FilterReduceExpressionsRule, ReduceExpressionsRule.JoinReduceExpressionsRule, ReduceExpressionsRule.ProjectReduceExpressionsRule, ReduceExpressionsRule.ReducibleExprLocator, ReduceExpressionsRule.RexReplacer, ReduceExpressionsRule.WindowReduceExpressionsRule

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.rel.rules.ReduceExpressionsRule

EXCLUSION_PATTERN

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
	FilterReduceExpressionsRule(Class<? extends Filter> filterClass, boolean matchNullability, RelBuilderFactory relBuilderFactory)	Deprecated.
	FilterReduceExpressionsRule(Class<? extends Filter> filterClass, RelBuilderFactory relBuilderFactory)	Deprecated.
protected	FilterReduceExpressionsRule(ReduceExpressionsRule.FilterReduceExpressionsRule.FilterReduceExpressionsRuleConfig config)	Creates a FilterReduceExpressionsRule.

Method Summary

Modifier and Type	Method	Description
protected RelNode	createEmptyRelOrEquivalent(RelOptRuleCall call, Filter input)	For static schema systems, a filter that is always false or null can be replaced by a values operator that produces no rows, as the schema information can just be taken from the input Rel.
void	onMatch(RelOptRuleCall call)	Receives notification about a rule match.

Methods inherited from class org.apache.calcite.rel.rules.ReduceExpressionsRule

findReducibleExps, predicateConstants, pushPredicateIntoCase, reduceExpressions, reduceExpressions, reduceExpressions, reduceExpressionsInternal, substitute

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

FilterReduceExpressionsRule

protected FilterReduceExpressionsRule(ReduceExpressionsRule.FilterReduceExpressionsRule.FilterReduceExpressionsRuleConfig config)

Creates a FilterReduceExpressionsRule.

FilterReduceExpressionsRule

@Deprecated
public FilterReduceExpressionsRule(Class<? extends Filter> filterClass,
 RelBuilderFactory relBuilderFactory)

Deprecated.

FilterReduceExpressionsRule

@Deprecated
public FilterReduceExpressionsRule(Class<? extends Filter> filterClass,
 boolean matchNullability,
 RelBuilderFactory relBuilderFactory)

Deprecated.

Method Details

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)

createEmptyRelOrEquivalent

protected RelNode createEmptyRelOrEquivalent(RelOptRuleCall call,
 Filter input)

For static schema systems, a filter that is always false or null can be replaced by a values operator that produces no rows, as the schema information can just be taken from the input Rel. In dynamic schema environments, the filter might have an unknown input type, in these cases they must define a system specific alternative to a Values operator, such as inserting a limit 0 instead of a filter on top of the original input.

The default implementation of this method is to call RelBuilder.empty(), which for the static schema will be optimized to an empty Values.

Parameters:

input - rel to replace, assumes caller has already determined equivalence to Values operation for 0 records or a false filter.

Returns:

equivalent but less expensive replacement rel