io.crate.planner.node.dql.join

Class NestedLoop

java.lang.Object

io.crate.planner.PlanAndPlannedAnalyzedRelation

io.crate.planner.node.dql.join.NestedLoop

All Implemented Interfaces:

AnalyzedRelation, PlannedAnalyzedRelation, Plan

public class NestedLoop
extends PlanAndPlannedAnalyzedRelation

Plan that will be executed with the awesome nested loop algorithm performing CROSS JOINs This Plan makes a lot of assumptions:

• limit and offset are already pushed down to left and right plan nodes
• where clause is already splitted to left and right plan nodes
• order by symbols are already splitted, too
• if the first order by symbol in the whole statement is from the left node, set leftOuterLoop to true, otherwise to false

Properties:

• the resulting outputs from the join operations are the same, no matter if leftOuterLoop is true or not - so the projections added, can assume the same order of symbols, first symbols from left, then from right. If sth. else is selected a projection has to reorder those.

Field Summary

Fields inherited from interface io.crate.analyze.relations.PlannedAnalyzedRelation

IS_NOOP

Constructor Summary

Constructors

Constructor and Description
NestedLoop(NestedLoopPhase nestedLoopPhase, PlannedAnalyzedRelation left, PlannedAnalyzedRelation right, MergePhase localMerge, java.util.Collection<java.lang.String> handlerNodes) create a new NestedLoop side in the outer loop, the right in the inner.

Method Summary

Modifier and Type	Method and Description
<C,R> R	accept(PlanVisitor<C,R> visitor, C context)
void	addProjection(Projection projection)
java.util.UUID	jobId()
PlannedAnalyzedRelation	left()
MergePhase	localMerge()
NestedLoopPhase	nestedLoopPhase()
boolean	resultIsDistributed()
UpstreamPhase	resultPhase()
PlannedAnalyzedRelation	right()

Methods inherited from class io.crate.planner.PlanAndPlannedAnalyzedRelation

accept, fields, getField, getQualifiedName, getWritableField, plan, setQualifiedName

Methods inherited from class java.lang.Object

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

Constructor Detail

NestedLoop

public NestedLoop(NestedLoopPhase nestedLoopPhase,
                  PlannedAnalyzedRelation left,
                  PlannedAnalyzedRelation right,
                  @Nullable
                  MergePhase localMerge,
                  java.util.Collection<java.lang.String> handlerNodes)

create a new NestedLoop side in the outer loop, the right in the inner. Resulting in rows like: a | 1 a | 2 a | 3 b | 1 b | 2 b | 3 This is the case if the left relation is referenced by the first order by symbol references. E.g. for ORDER BY left.a, right.b If false, the nested loop is executed the other way around. With the following results: a | 1 b | 1 a | 2 b | 2 a | 3 b | 3

Method Detail

left

public PlannedAnalyzedRelation left()

right

public PlannedAnalyzedRelation right()

nestedLoopPhase

public NestedLoopPhase nestedLoopPhase()

addProjection

public void addProjection(Projection projection)

resultIsDistributed

public boolean resultIsDistributed()

resultPhase

public UpstreamPhase resultPhase()

accept

public <C,R> R accept(PlanVisitor<C,R> visitor,
                      C context)

jobId

public java.util.UUID jobId()

localMerge

@Nullable
public MergePhase localMerge()