org.apache.calcite.plan

Class SubstitutionVisitor.AggregateOnProjectToAggregateUnifyRule

java.lang.Object

org.apache.calcite.plan.SubstitutionVisitor.UnifyRule

org.apache.calcite.plan.SubstitutionVisitor.AbstractUnifyRule

org.apache.calcite.plan.SubstitutionVisitor.AggregateOnProjectToAggregateUnifyRule

Enclosing class:

SubstitutionVisitor

private static class SubstitutionVisitor.AggregateOnProjectToAggregateUnifyRule
extends SubstitutionVisitor.AbstractUnifyRule

Implementation of SubstitutionVisitor.UnifyRule that matches a MutableAggregate on a MutableProject query to an MutableAggregate target.

The rule is necessary when we unify query=Aggregate(x) with target=Aggregate(x, y). Query will tend to have an extra Project(x) on its input, which this rule knows is safe to ignore.

Field Summary

Fields

Modifier and Type	Field and Description
static SubstitutionVisitor.AggregateOnProjectToAggregateUnifyRule	INSTANCE

Fields inherited from class org.apache.calcite.plan.SubstitutionVisitor.UnifyRule

queryOperand, slotCount, targetOperand

Constructor Summary

Constructors

Modifier	Constructor and Description
private	AggregateOnProjectToAggregateUnifyRule()

Method Summary

Modifier and Type	Method and Description
SubstitutionVisitor.UnifyResult	apply(SubstitutionVisitor.UnifyRuleCall call) Applies this rule to a particular node in a query.

Methods inherited from class org.apache.calcite.plan.SubstitutionVisitor.AbstractUnifyRule

any, isValid, operand, query, target

Methods inherited from class org.apache.calcite.plan.SubstitutionVisitor.UnifyRule

copy, match

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

INSTANCE

public static final SubstitutionVisitor.AggregateOnProjectToAggregateUnifyRule INSTANCE

Constructor Detail

AggregateOnProjectToAggregateUnifyRule

private AggregateOnProjectToAggregateUnifyRule()

Method Detail

apply

public SubstitutionVisitor.UnifyResult apply(SubstitutionVisitor.UnifyRuleCall call)

Description copied from class: SubstitutionVisitor.UnifyRule

Applies this rule to a particular node in a query. The goal is to convert query into target. Before the rule is invoked, Calcite has made sure that query's children are equivalent to target's children.

There are 3 possible outcomes:

• query already exactly matches target; returns target
• query is sufficiently close to a match for target; returns target
• query cannot be made to match target; returns null

REVIEW: Is possible that we match query PLUS one or more of its ancestors?

Specified by:

apply in class SubstitutionVisitor.UnifyRule

Parameters:

call - Input parameters