Package io.trino.sql.planner.iterative.rule

Class PushPredicateThroughProjectIntoWindow

java.lang.Object

io.trino.sql.planner.iterative.rule.PushPredicateThroughProjectIntoWindow

All Implemented Interfaces:

Rule<FilterNode>

public class PushPredicateThroughProjectIntoWindow
extends Object
implements Rule<FilterNode>

This rule pushes filter predicate concerning a ranking symbol into WindowNode by converting it into TopNRankingNode. It skips an identity projection separating FilterNode from WindowNode in the plan tree. TODO This rule should be removed as soon as WindowNode becomes capable of absorbing pruning projections (i.e. capable of pruning outputs).

Transforms:

 - Filter (ranking <= 5 && a > 1)
     - Project (a, ranking)
         - Window ([row_number()|rank()] OVER (ORDER BY a))
             - source (a, b)
 

into:

 - Filter (a > 1)
     - Project (a, ranking)
         - TopNRanking (type = [ROW_NUMBER|RANK], maxRankingPerPartition = 5, order by a)
             - source (a, b)
 

Nested Class Summary

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

Rule.Context, Rule.Result

Constructor Summary

Constructors

Constructor	Description
PushPredicateThroughProjectIntoWindow(Metadata metadata, TypeOperators typeOperators)

Method Summary

Modifier and Type	Method	Description
Rule.Result	apply(FilterNode filter, Captures captures, Rule.Context context)
Pattern<FilterNode>	getPattern()	Returns a pattern to which plan nodes this rule applies.
boolean	isEnabled(Session session)

Methods inherited from class java.lang.Object

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

Constructor Detail

PushPredicateThroughProjectIntoWindow

public PushPredicateThroughProjectIntoWindow(Metadata metadata,
                                             TypeOperators typeOperators)

Method Detail

getPattern

public Pattern<FilterNode> getPattern()

Description copied from interface: Rule

Returns a pattern to which plan nodes this rule applies.

Specified by:

getPattern in interface Rule<FilterNode>

isEnabled

public boolean isEnabled(Session session)

Specified by:

isEnabled in interface Rule<FilterNode>

apply

public Rule.Result apply(FilterNode filter,
                         Captures captures,
                         Rule.Context context)

Specified by:

apply in interface Rule<FilterNode>