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

Class PushPredicateThroughProjectIntoRowNumber

java.lang.Object

io.prestosql.sql.planner.iterative.rule.PushPredicateThroughProjectIntoRowNumber

All Implemented Interfaces:

Rule<FilterNode>

public class PushPredicateThroughProjectIntoRowNumber
extends Object
implements Rule<FilterNode>

This rule pushes filter predicate concerning row number symbol into RowNumberNode by modifying maxRowCountPerPartition. It skips an identity projection separating FilterNode from RowNumberNode in the plan tree. TODO This rule should be removed as soon as RowNumberNode becomes capable of absorbing pruning projections (i.e. capable of pruning outputs).

Transforms:

 - Filter (rowNumber <= 5 && a > 1)
     - Project (a, rowNumber)
         - RowNumber (maxRowCountPerPartition = 10)
             - source (a, b)
 

into:

 - Filter (a > 1)
     - Project (a, rowNumber)
         - RowNumber (maxRowCountPerPartition = 5)
             - source (a, b)
 

Nested Class Summary

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

Rule.Context, Rule.Result

Constructor Summary

Constructors

Constructor	Description
PushPredicateThroughProjectIntoRowNumber(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.

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

PushPredicateThroughProjectIntoRowNumber

public PushPredicateThroughProjectIntoRowNumber(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>

apply

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

Specified by:

apply in interface Rule<FilterNode>