com.bigdata.bop.join

Class HashJoinOp<E>

java.lang.Object

com.bigdata.bop.CoreBaseBOp

com.bigdata.bop.BOpBase

com.bigdata.bop.PipelineOp

com.bigdata.bop.join.HashJoinOp<E>

All Implemented Interfaces:

BOp, IShardwisePipelineOp<E>, IPropertySet, Serializable, Cloneable

Direct Known Subclasses:

HTreeHashJoinOp, JVMHashJoinOp

public abstract class HashJoinOp<E>
extends PipelineOp
implements IShardwisePipelineOp<E>

Abstract base class for both JVM and native memory hash join against an IAccessPath. The source solutions from the pipeline are buffered on a hash index. Depending on the implementation, the hash index may have a threshold that will trigger an evaluation pass of the hash join. If not, then the hash join will run exactly once. When the hash join runs, the access path is scanned and the hash index (of intermediate solutions from the pipeline) is probed for each solution read from the IAccessPath. Solutions which join are output.

Author:

Bryan Thompson

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	HashJoinOp.Annotations

Field Summary

Fields inherited from class com.bigdata.bop.CoreBaseBOp

DEFAULT_INITIAL_CAPACITY

Fields inherited from interface com.bigdata.bop.BOp

NOANNS, NOARGS

Constructor Summary

Constructors

Constructor and Description
HashJoinOp(BOp[] args, Map<String,Object> annotations)
HashJoinOp(BOp[] args, NV... annotations)
HashJoinOp(HashJoinOp<E> op)

Method Summary

Methods

Modifier and Type	Method and Description
FutureTask<Void>	eval(BOpContext<IBindingSet> context) Return a FutureTask which computes the operator against the evaluation context.
IPredicate<E>	getPredicate() The predicate which reads or writes on the shard.
protected boolean	isOptional() Return true iff the predicate associated with the join is optional.
protected abstract IHashJoinUtility	newState(BOpContext<IBindingSet> context, INamedSolutionSetRef namedSetRef, JoinTypeEnum joinType) Return the instance of the IHashJoinUtility to be used by this operator.
BaseJoinStats	newStats() Return a new object which can be used to collect statistics on the operator evaluation.
protected abstract boolean	runHashJoin(BOpContext<?> context, IHashJoinUtility state) Return true if ChunkTask#doHashJoin() should be executed in a given operator ChunkTask invocation.

Methods inherited from class com.bigdata.bop.PipelineOp

assertAtOnceJavaHeapOp, assertMaxParallelOne, getChunkCapacity, getChunkOfChunksCapacity, getChunkTimeout, getMaxMemory, getMaxParallel, isAtOnceEvaluation, isBlockedEvaluation, isLastPassRequested, isPipelinedEvaluation, isReorderSolutions, isSharedState

Methods inherited from class com.bigdata.bop.BOpBase

__replaceArg, _clearProperty, _set, _setProperty, annotations, annotationsCopy, annotationsEqual, annotationsRef, argIterator, args, argsCopy, arity, clearAnnotations, clearProperty, deepCopy, deepCopy, get, getProperty, setArg, setProperty, setUnboundProperty, toArray, toArray

Methods inherited from class com.bigdata.bop.CoreBaseBOp

annotationsEqual, annotationsToString, annotationsToString, annotationValueToString, checkArgs, clone, equals, getEvaluationContext, getId, getProperty, getRequiredProperty, hashCode, indent, isController, mutation, shortenName, toShortString, toString, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

HashJoinOp

public HashJoinOp(HashJoinOp<E> op)

Parameters:

op -

HashJoinOp

public HashJoinOp(BOp[] args,
          NV... annotations)

HashJoinOp

public HashJoinOp(BOp[] args,
          Map<String,Object> annotations)

Parameters:

args -

annotations -

Method Detail

getPredicate

public IPredicate<E> getPredicate()

The predicate which reads or writes on the shard.

Specified by:

getPredicate in interface IShardwisePipelineOp<E>

See Also:

AccessPathJoinAnnotations.PREDICATE

isOptional

protected boolean isOptional()

Return true iff the predicate associated with the join is optional.

See Also:

IPredicate.Annotations#OPTIONAL

newStats

public BaseJoinStats newStats()

Description copied from class: PipelineOp

Return a new object which can be used to collect statistics on the operator evaluation. This may be overridden to return a more specific class depending on the operator.

Overrides:

newStats in class PipelineOp

newState

protected abstract IHashJoinUtility newState(BOpContext<IBindingSet> context,
                        INamedSolutionSetRef namedSetRef,
                        JoinTypeEnum joinType)

Return the instance of the IHashJoinUtility to be used by this operator. This method is invoked once, the first time this operator is evaluated. The returned IHashJoinUtility reference is attached to the IQueryAttributes and accessed there on subsequent evaluation passes for this operator.

Parameters:

context - The BOpEvaluationContext

namedSetRef - Metadata to identify the named solution set.

joinType - The type of join.

runHashJoin

protected abstract boolean runHashJoin(BOpContext<?> context,
                  IHashJoinUtility state)

Return true if ChunkTask#doHashJoin() should be executed in a given operator ChunkTask invocation.

Parameters:

context - The operator evaluation context.

state - The IHashJoinUtility instance.

eval

public FutureTask<Void> eval(BOpContext<IBindingSet> context)

Description copied from class: PipelineOp

Return a FutureTask which computes the operator against the evaluation context. The caller is responsible for executing the FutureTask (this gives them the ability to hook the completion of the computation).

Specified by:

eval in class PipelineOp

Parameters:

context - The evaluation context.

Returns:

The FutureTask which will compute the operator's evaluation.