Package io.prestosql.sql.planner.iterative.rule

Class TransformExistsApplyToCorrelatedJoin

java.lang.Object

io.prestosql.sql.planner.iterative.rule.TransformExistsApplyToCorrelatedJoin

All Implemented Interfaces:

Rule<ApplyNode>

public class TransformExistsApplyToCorrelatedJoin
extends Object
implements Rule<ApplyNode>

EXISTS is modeled as (if correlated predicates are equality comparisons):

     - Project(exists := COALESCE(subqueryTrue, false))
       - CorrelatedJoin(LEFT)
         - input
         - Project(subqueryTrue := true)
           - Limit(count=1)
             - subquery
 

or:

     - CorrelatedJoin(LEFT)
       - input
       - Project($0 > 0)
         - Aggregation(COUNT(*))
           - subquery
 

otherwise

Nested Class Summary

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

Rule.Context, Rule.Result

Constructor Summary

Constructors

Constructor	Description
TransformExistsApplyToCorrelatedJoin(Metadata metadata)

Method Summary

Modifier and Type	Method	Description
Rule.Result	apply(ApplyNode parent, Captures captures, Rule.Context context)
Pattern<ApplyNode>	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

TransformExistsApplyToCorrelatedJoin

public TransformExistsApplyToCorrelatedJoin(Metadata metadata)

Method Detail

getPattern

public Pattern<ApplyNode> getPattern()

Description copied from interface: Rule

Returns a pattern to which plan nodes this rule applies.

Specified by:

getPattern in interface Rule<ApplyNode>

apply

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

Specified by:

apply in interface Rule<ApplyNode>