io.crate.execution.engine.join

Class JoinOperations

java.lang.Object

io.crate.execution.engine.join.JoinOperations

public final class JoinOperations
extends java.lang.Object

Method Summary

Modifier and Type	Method and Description
static MergePhase	buildMergePhaseForJoin(PlannerContext plannerContext, ResultDescription resultDescription, java.util.Collection<java.lang.String> executionNodes)
static java.util.LinkedHashMap<java.util.Set<QualifiedName>,JoinPair>	buildRelationsToJoinPairsMap(java.util.List<JoinPair> joinPairs)
static java.util.List<JoinPair>	convertImplicitJoinConditionsToJoinPairs(java.util.List<JoinPair> explicitJoinPairs, java.util.Map<java.util.Set<QualifiedName>,Symbol> splitQueries) Converts any implicit join conditions of the WHERE clause to explicit JoinPair.
static Projection	createJoinProjection(java.util.List<Symbol> outputs, java.util.List<Symbol> joinOutputs) Creates an EvalProjection to ensure that the join output symbols are emitted in the original order as a possible outer operator (e.g.
static boolean	isMergePhaseNeeded(java.util.Collection<java.lang.String> executionNodes, ResultDescription resultDescription, boolean isDistributed)

Methods inherited from class java.lang.Object

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

Method Detail

isMergePhaseNeeded

public static boolean isMergePhaseNeeded(java.util.Collection<java.lang.String> executionNodes,
                                         ResultDescription resultDescription,
                                         boolean isDistributed)

buildMergePhaseForJoin

public static MergePhase buildMergePhaseForJoin(PlannerContext plannerContext,
                                                ResultDescription resultDescription,
                                                java.util.Collection<java.lang.String> executionNodes)

createJoinProjection

public static Projection createJoinProjection(java.util.List<Symbol> outputs,
                                              java.util.List<Symbol> joinOutputs)

Creates an EvalProjection to ensure that the join output symbols are emitted in the original order as a possible outer operator (e.g. GROUP BY) is relying on the order. The order could have been changed due to the switch-table optimizations

Parameters:

outputs - List of join output symbols in their original order.

joinOutputs - List of join output symbols after possible re-ordering due optimizations.

buildRelationsToJoinPairsMap

public static java.util.LinkedHashMap<java.util.Set<QualifiedName>,JoinPair> buildRelationsToJoinPairsMap(java.util.List<JoinPair> joinPairs)

convertImplicitJoinConditionsToJoinPairs

public static java.util.List<JoinPair> convertImplicitJoinConditionsToJoinPairs(java.util.List<JoinPair> explicitJoinPairs,
                                                                                java.util.Map<java.util.Set<QualifiedName>,Symbol> splitQueries)

Converts any implicit join conditions of the WHERE clause to explicit JoinPair. Every join condition that gets to be converted is removed from the splitQueries

Parameters:

explicitJoinPairs - The explicitJoinPairs as originally written in the query

splitQueries - The remaining queries of the WHERE clause split by involved relations

Returns:

the new list of JoinPair