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

Class DecorrelateLeftUnnestWithGlobalAggregation

java.lang.Object

io.trino.sql.planner.iterative.rule.DecorrelateLeftUnnestWithGlobalAggregation

All Implemented Interfaces:

Rule<CorrelatedJoinNode>

public class DecorrelateLeftUnnestWithGlobalAggregation
extends Object
implements Rule<CorrelatedJoinNode>

This rule finds correlated UnnestNode in CorrelatedJoinNode's subquery and folds them into UnnestNode representing LEFT JOIN UNNEST. This rule transforms plans, where: - UnnestNode in subquery is based only on correlation symbols - UnnestNode in subquery is LEFT without filter - subquery contains global aggregation over the result of unnest Additionally, other global aggregations, grouped aggregations and projections in subquery are supported.

Transforms:

 - CorrelatedJoin (LEFT or INNER) on true, correlation(c1, c2)
      - Input (a, c1, c2)
      - Aggregation
           global grouping
           agg <- agg1(x)
           - Projection
                x <- foo(y)
                - Aggregation
                     group by (g)
                     y <- agg2(u)
                     - Unnest LEFT
                          g <- unnest(c1)
                          u <- unnest(c2)
                          replicate: ()
 

Into:

 - Projection (restrict outputs)
      - Aggregation
           group by (a, c1, c2, unique)
           agg <- agg1(x)
           - Projection
                x <- foo(y)
                - Aggregation
                     group by (g, a, c1, c2, unique)
                     y <- agg2(u)
                     - Unnest LEFT
                          g <- unnest(c1)
                          u <- unnest(c2)
                          replicate: (a, c1, c2, unique)
                          - AssignUniqueId unique
                               - Input (a, c1, c2)
 

Nested Class Summary

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

Rule.Context, Rule.Result

Constructor Summary

Constructors

Constructor	Description
DecorrelateLeftUnnestWithGlobalAggregation()

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

DecorrelateLeftUnnestWithGlobalAggregation

public DecorrelateLeftUnnestWithGlobalAggregation()

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>