io.prestosql.sql.planner.iterative.rule

Class TransformCorrelatedSingleRowSubqueryToProject

java.lang.Object

io.prestosql.sql.planner.iterative.rule.TransformCorrelatedSingleRowSubqueryToProject

All Implemented Interfaces:

Rule<LateralJoinNode>

public class TransformCorrelatedSingleRowSubqueryToProject
extends Object
implements Rule<LateralJoinNode>

This optimizer can rewrite correlated single row subquery to projection in a way described here: From:

 - Lateral(with correlation list: [A, C])
   - (input) plan which produces symbols: [A, B, C]
   - (subquery)
     - Project (A + C)
       - single row VALUES()
 

to:

   - Project(A, B, C, A + C)
       - (input) plan which produces symbols: [A, B, C]
 

Nested Class Summary

Nested classes/interfaces inherited from interface io.prestosql.sql.planner.iterative.Rule

Rule.Context, Rule.Result

Constructor Summary

Constructors

Constructor and Description
TransformCorrelatedSingleRowSubqueryToProject()

Method Summary

Modifier and Type	Method and Description
Rule.Result	apply(LateralJoinNode parent, Captures captures, Rule.Context context)
Pattern<LateralJoinNode>	getPattern() Returns a pattern to which plan nodes this rule applies.

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.prestosql.sql.planner.iterative.Rule

isEnabled

Constructor Detail

TransformCorrelatedSingleRowSubqueryToProject

public TransformCorrelatedSingleRowSubqueryToProject()

Method Detail

getPattern

public Pattern<LateralJoinNode> getPattern()

Description copied from interface: Rule

Returns a pattern to which plan nodes this rule applies.

Specified by:

getPattern in interface Rule<LateralJoinNode>

apply

public Rule.Result apply(LateralJoinNode parent,
                         Captures captures,
                         Rule.Context context)

Specified by:

apply in interface Rule<LateralJoinNode>