org.apache.calcite.plan

Class SubstitutionVisitor.ScanToProjectUnifyRule

java.lang.Object

org.apache.calcite.plan.SubstitutionVisitor.UnifyRule

org.apache.calcite.plan.SubstitutionVisitor.AbstractUnifyRule

org.apache.calcite.plan.SubstitutionVisitor.ScanToProjectUnifyRule

Enclosing class:

SubstitutionVisitor

private static class SubstitutionVisitor.ScanToProjectUnifyRule
extends SubstitutionVisitor.AbstractUnifyRule

Implementation of SubstitutionVisitor.UnifyRule that matches LogicalTableScan.

Field Summary

Fields

Modifier and Type	Field and Description
static SubstitutionVisitor.ScanToProjectUnifyRule	INSTANCE

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

queryOperand, slotCount, targetOperand

Constructor Summary

Constructors

Modifier	Constructor and Description
private	ScanToProjectUnifyRule()

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.ScanToProjectUnifyRule INSTANCE

Constructor Detail

ScanToProjectUnifyRule

private ScanToProjectUnifyRule()

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