io.prestosql.sql.planner.iterative.rule

Class TransformCorrelatedInPredicateToJoin

java.lang.Object

io.prestosql.sql.planner.iterative.rule.TransformCorrelatedInPredicateToJoin

All Implemented Interfaces:

Rule<ApplyNode>

public class TransformCorrelatedInPredicateToJoin
extends Object
implements Rule<ApplyNode>

Replaces correlated ApplyNode with InPredicate expression with SemiJoin

Transforms:

 - Apply (output: a in B.b)
    - input: some plan A producing symbol a
    - subquery: some plan B producing symbol b, using symbols from A
 

Into:

 - Project (output: CASE WHEN (countmatches > 0) THEN true WHEN (countnullmatches > 0) THEN null ELSE false END)
   - Aggregate (countmatches=count(*) where a, b not null; countnullmatches where a,b null but buildSideKnownNonNull is not null)
     grouping by (A'.*)
     - LeftJoin on (A and B correlation condition)
       - AssignUniqueId (A')
         - A
 

See Also:

TransformCorrelatedScalarAggregationToJoin

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
TransformCorrelatedInPredicateToJoin()

Method Summary

Modifier and Type	Method and Description
Rule.Result	apply(ApplyNode apply, 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

TransformCorrelatedInPredicateToJoin

public TransformCorrelatedInPredicateToJoin()

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 apply,
                         Captures captures,
                         Rule.Context context)

Specified by:

apply in interface Rule<ApplyNode>