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

Class TransformCorrelatedGlobalAggregationWithoutProjection

java.lang.Object

io.trino.sql.planner.iterative.rule.TransformCorrelatedGlobalAggregationWithoutProjection

All Implemented Interfaces:

Rule<CorrelatedJoinNode>

public class TransformCorrelatedGlobalAggregationWithoutProjection
extends Object
implements Rule<CorrelatedJoinNode>

This rule decorrelates a correlated subquery with: - single global aggregation, or - global aggregation over distinct operator (grouped aggregation with no aggregation assignments) It is similar to TransformCorrelatedGlobalAggregationWithProjection rule, but does not support projection over aggregation in the subquery

In the case of single aggregation, it transforms:

 - CorrelatedJoin LEFT or INNER (correlation: [c], filter: true, output: a, count, agg)
      - Input (a, c)
      - Aggregation global
        count <- count(*)
        agg <- agg(b)
           - Source (b) with correlated filter (b > c)
 

Into:

 - Project (a <- a, count <- count, agg <- agg)
      - Aggregation (group by [a, c, unique])
        count <- count(*) mask(non_null)
        agg <- agg(b) mask(non_null)
           - LEFT join (filter: b > c)
                - UniqueId (unique)
                     - Input (a, c)
                - Project (non_null <- TRUE)
                     - Source (b) decorrelated
 

In the case of global aggregation over distinct operator, it transforms:

 - CorrelatedJoin LEFT or INNER (correlation: [c], filter: true, output: a, count, agg)
      - Input (a, c)
      - Aggregation global
        count <- count(*)
        agg <- agg(b)
           - Aggregation "distinct operator" group by [b]
                - Source (b) with correlated filter (b > c)
 

Into:

 - Project (a <- a, count <- count, agg <- agg)
      - Aggregation (group by [a, c, unique])
        count <- count(*) mask(non_null)
        agg <- agg(b) mask(non_null)
           - Aggregation "distinct operator" group by [a, c, unique, non_null, b]
                - LEFT join (filter: b > c)
                     - UniqueId (unique)
                          - Input (a, c)
                     - Project (non_null <- TRUE)
                          - Source (b) decorrelated
 

Nested Class Summary

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

Rule.Context, Rule.Result

Constructor Summary

Constructors

Constructor	Description
TransformCorrelatedGlobalAggregationWithoutProjection(Metadata metadata)

Method Summary

Modifier and Type	Method	Description
Rule.Result	apply(CorrelatedJoinNode correlatedJoinNode, Captures captures, Rule.Context context)
Pattern<CorrelatedJoinNode>	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.trino.sql.planner.iterative.Rule

isEnabled

Constructor Detail

TransformCorrelatedGlobalAggregationWithoutProjection

public TransformCorrelatedGlobalAggregationWithoutProjection(Metadata metadata)

Method Detail

getPattern

public Pattern<CorrelatedJoinNode> getPattern()

Description copied from interface: Rule

Returns a pattern to which plan nodes this rule applies.

Specified by:

getPattern in interface Rule<CorrelatedJoinNode>

apply

public Rule.Result apply(CorrelatedJoinNode correlatedJoinNode,
                         Captures captures,
                         Rule.Context context)

Specified by:

apply in interface Rule<CorrelatedJoinNode>