Class ExecOpParallelMultiwayLeftJoin

java.lang.Object

se.liu.ida.hefquin.engine.queryplan.executable.impl.ops.BaseForExecOps

se.liu.ida.hefquin.engine.queryplan.executable.impl.ops.UnaryExecutableOpBase

se.liu.ida.hefquin.engine.queryplan.executable.impl.ops.UnaryExecutableOpBaseWithBatching

se.liu.ida.hefquin.engine.queryplan.executable.impl.ops.ExecOpParallelMultiwayLeftJoin

All Implemented Interfaces:

StatsProvider, ExecutableOperator, UnaryExecutableOp

public class ExecOpParallelMultiwayLeftJoin
extends UnaryExecutableOpBaseWithBatching

TODO: Provide a description of the algorithm implemented by this class.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	ExecOpParallelMultiwayLeftJoin.Worker

Field Summary

Fields

Modifier and Type	Field	Description
protected final Set<List<org.apache.jena.graph.Node>>	bindingsForJoinVariable
static final int	DEFAULT_BATCH_SIZE
protected final List<SolutionMappingsIndex>	indexes
protected final ExpectedVariables	inputVarsFromNonOptionalPart
protected final List<org.apache.jena.sparql.core.Var>	joinVars
protected final List<LogicalOpRequest<?,?>>	optionalParts

Fields inherited from class se.liu.ida.hefquin.engine.queryplan.executable.impl.ops.UnaryExecutableOpBaseWithBatching

batchSize, collectedInputSolMaps

Fields inherited from class se.liu.ida.hefquin.engine.queryplan.executable.impl.ops.BaseForExecOps

collectExceptions

Constructor Summary

Constructors

Constructor	Description
ExecOpParallelMultiwayLeftJoin(boolean collectExceptions, ExpectedVariables inputVarsFromNonOptionalPart, List<LogicalOpRequest<?,?>> optionalParts)
ExecOpParallelMultiwayLeftJoin(boolean collectExceptions, ExpectedVariables inputVarsFromNonOptionalPart, LogicalOpRequest<?,?>... optionalParts)

Method Summary

Modifier and Type	Method	Description
protected void	_concludeExecution(List<SolutionMapping> batch, IntermediateResultElementSink sink, ExecutionContext execCxt)	Implementations of this function need to process the given batch of solution mappings as last input, conclude the execution of this operator, and send the remaining result elements (if any) to the given sink.
protected void	_processBatch(List<SolutionMapping> input, IntermediateResultElementSink sink, ExecutionContext execCxt)	Implementations of this function need to process the given batch of solution mappings as input and send the produced result elements (if any) to the given sink.
protected List<SolutionMapping>	determineInputForParallelProcess(List<SolutionMapping> input)	Preprocess the given list of solution mappings to identify the input solution mappings that do not need to be considered during the parallel phase of the algorithm (because they have bindings for the join variables such that there already was an earlier input solution mapping with the same bindings).
protected Set<SolutionMapping>	merge(SolutionMapping inputSol)
protected void	mergePhase(Iterable<SolutionMapping> inputSolMaps, IntermediateResultElementSink sink)
protected void	parallelPhase(List<SolutionMapping> inputForParallelProcess, ExecutionContext execCxt)

Methods inherited from class se.liu.ida.hefquin.engine.queryplan.executable.impl.ops.UnaryExecutableOpBaseWithBatching

_concludeExecution, _process, createStats, resetStats

Methods inherited from class se.liu.ida.hefquin.engine.queryplan.executable.impl.ops.UnaryExecutableOpBase

_process, concludeExecution, getStats, process, process

Methods inherited from class se.liu.ida.hefquin.engine.queryplan.executable.impl.ops.BaseForExecOps

getExceptionsCaughtDuringExecution, recordExceptionCaughtDuringExecution

Methods inherited from class java.lang.Object

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

Methods inherited from interface se.liu.ida.hefquin.engine.queryplan.executable.ExecutableOperator

getExceptionsCaughtDuringExecution

Field Details

DEFAULT_BATCH_SIZE

public static final int DEFAULT_BATCH_SIZE

See Also:

• Constant Field Values

inputVarsFromNonOptionalPart

protected final ExpectedVariables inputVarsFromNonOptionalPart

optionalParts

protected final List<LogicalOpRequest<?,?>> optionalParts

indexes

protected final List<SolutionMappingsIndex> indexes

joinVars

protected final List<org.apache.jena.sparql.core.Var> joinVars

bindingsForJoinVariable

protected final Set<List<org.apache.jena.graph.Node>> bindingsForJoinVariable

Constructor Details

ExecOpParallelMultiwayLeftJoin

public ExecOpParallelMultiwayLeftJoin(boolean collectExceptions,
 ExpectedVariables inputVarsFromNonOptionalPart,
 LogicalOpRequest<?,?>... optionalParts)

ExecOpParallelMultiwayLeftJoin

public ExecOpParallelMultiwayLeftJoin(boolean collectExceptions,
 ExpectedVariables inputVarsFromNonOptionalPart,
 List<LogicalOpRequest<?,?>> optionalParts)

Method Details

_processBatch

protected void _processBatch(List<SolutionMapping> input,
 IntermediateResultElementSink sink,
 ExecutionContext execCxt)
                      throws ExecOpExecutionException

Description copied from class: UnaryExecutableOpBaseWithBatching

Implementations of this function need to process the given batch of solution mappings as input and send the produced result elements (if any) to the given sink. If an exception occurs while processing the batch, then this exception needs to be thrown.

Specified by:

_processBatch in class UnaryExecutableOpBaseWithBatching

Throws:

ExecOpExecutionException

determineInputForParallelProcess

protected List<SolutionMapping> determineInputForParallelProcess(List<SolutionMapping> input)

Preprocess the given list of solution mappings to identify the input solution mappings that do not need to be considered during the parallel phase of the algorithm (because they have bindings for the join variables such that there already was an earlier input solution mapping with the same bindings). The list returned by this function contains only the solution mappings from the given list that need to be considered.

parallelPhase

protected void parallelPhase(List<SolutionMapping> inputForParallelProcess,
 ExecutionContext execCxt)
                      throws ExecOpExecutionException

Throws:

ExecOpExecutionException

mergePhase

protected void mergePhase(Iterable<SolutionMapping> inputSolMaps,
 IntermediateResultElementSink sink)

merge

protected Set<SolutionMapping> merge(SolutionMapping inputSol)

_concludeExecution

protected void _concludeExecution(List<SolutionMapping> batch,
 IntermediateResultElementSink sink,
 ExecutionContext execCxt)
                           throws ExecOpExecutionException

Description copied from class: UnaryExecutableOpBaseWithBatching

Implementations of this function need to process the given batch of solution mappings as last input, conclude the execution of this operator, and send the remaining result elements (if any) to the given sink. Notice that the given batch of solution mappings may be empty! If an exception occurs during this process, then this exception needs to be thrown.

Specified by:

_concludeExecution in class UnaryExecutableOpBaseWithBatching

Throws:

ExecOpExecutionException