org.eclipse.rdf4j.federated.evaluation

Class SailFederationEvalStrategy

java.lang.Object

org.eclipse.rdf4j.query.algebra.evaluation.impl.StrictEvaluationStrategy

org.eclipse.rdf4j.federated.evaluation.FederationEvalStrategy

org.eclipse.rdf4j.federated.evaluation.SailFederationEvalStrategy

All Implemented Interfaces:

EvaluationStrategy, FederatedServiceResolver, FederatedServiceResolverClient, UUIDable

public class SailFederationEvalStrategy
extends FederationEvalStrategy

Implementation of a federation evaluation strategy which provides some special optimizations for Native (local) Sesame repositories. The most important optimization is to use prepared Queries that are already created in the internal representation used by Sesame. This is necessary to avoid String parsing overhead. Joins are executed using ControlledWorkerJoin

Author:

Andreas Schwarte

Field Summary

Fields inherited from class org.eclipse.rdf4j.federated.evaluation.FederationEvalStrategy

cache, executor, federationContext

Fields inherited from class org.eclipse.rdf4j.query.algebra.evaluation.impl.StrictEvaluationStrategy

dataset, serviceResolver, tripleSource

Constructor Summary

Constructors

Constructor and Description
SailFederationEvalStrategy(FederationContext federationContext)

Method Summary

Modifier and Type	Method and Description
CloseableIteration<BindingSet,QueryEvaluationException>	evaluateBoundJoinStatementPattern(StatementTupleExpr stmt, List<BindingSet> bindings) Evaluate a bound join at the relevant endpoint, i.e.
CloseableIteration<BindingSet,QueryEvaluationException>	evaluateExclusiveGroup(ExclusiveGroup group, BindingSet bindings)
CloseableIteration<BindingSet,QueryEvaluationException>	evaluateGroupedCheck(CheckStatementPattern stmt, List<BindingSet> bindings) Perform a grouped check at the relevant endpoints, i.e.
CloseableIteration<BindingSet,QueryEvaluationException>	executeJoin(ControlledWorkerScheduler<BindingSet> joinScheduler, CloseableIteration<BindingSet,QueryEvaluationException> leftIter, TupleExpr rightArg, Set<String> joinVars, BindingSet bindings, QueryInfo queryInfo) Execute the join in a separate thread using some join executor.

Methods inherited from class org.eclipse.rdf4j.federated.evaluation.FederationEvalStrategy

createSourceSelectionCache, evaluate, evaluate, evaluate, evaluate, evaluateAtStatementSources, evaluateAtStatementSources, evaluateAtStatementSources, evaluateExclusiveTupleExpr, evaluateLeftJoin, evaluateNaryUnion, evaluateNJoin, evaluateService, evaluateService, evaluateSingleSourceQuery, getStatements, optimize, optimizeExclusiveExpressions, optimizeJoinOrder, performSourceSelection, propagateServices

Methods inherited from class org.eclipse.rdf4j.query.algebra.evaluation.impl.StrictEvaluationStrategy

evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, evaluate, getLimit, getService, getUUID, getVarValue, getZeroLengthPathIterator, isReducedOrDistinct, isTrue, isUnbound, setFederatedServiceResolver, setOptimizerPipeline, setTrackResultSize, setTrackTime

Methods inherited from class java.lang.Object

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

Constructor Detail

SailFederationEvalStrategy

public SailFederationEvalStrategy(FederationContext federationContext)

Method Detail

evaluateBoundJoinStatementPattern

public CloseableIteration<BindingSet,QueryEvaluationException> evaluateBoundJoinStatementPattern(StatementTupleExpr stmt,
                                                                                                 List<BindingSet> bindings)
                                                                                          throws QueryEvaluationException

Description copied from class: FederationEvalStrategy

Evaluate a bound join at the relevant endpoint, i.e. i.e. for a group of bindings retrieve results for the bound statement from the relevant endpoints

Specified by:

evaluateBoundJoinStatementPattern in class FederationEvalStrategy

Returns:

the result iteration

Throws:

QueryEvaluationException

evaluateGroupedCheck

public CloseableIteration<BindingSet,QueryEvaluationException> evaluateGroupedCheck(CheckStatementPattern stmt,
                                                                                    List<BindingSet> bindings)
                                                                             throws QueryEvaluationException

Description copied from class: FederationEvalStrategy

Perform a grouped check at the relevant endpoints, i.e. for a group of bindings keep only those for which at least one endpoint provides a result to the bound statement.

Specified by:

evaluateGroupedCheck in class FederationEvalStrategy

Returns:

the result iteration

Throws:

QueryEvaluationException

executeJoin

public CloseableIteration<BindingSet,QueryEvaluationException> executeJoin(ControlledWorkerScheduler<BindingSet> joinScheduler,
                                                                           CloseableIteration<BindingSet,QueryEvaluationException> leftIter,
                                                                           TupleExpr rightArg,
                                                                           Set<String> joinVars,
                                                                           BindingSet bindings,
                                                                           QueryInfo queryInfo)
                                                                    throws QueryEvaluationException

Description copied from class: FederationEvalStrategy

Execute the join in a separate thread using some join executor. Join executors are for instance: - SynchronousJoin - SynchronousBoundJoin - ControlledWorkerJoin - ControlledWorkerBoundJoin For endpoint federation use controlled worker bound join, for local federation use controlled worker join. The other operators are there for completeness. Use FederationEvalStrategy.executor to execute the join (it is a runnable).

Specified by:

executeJoin in class FederationEvalStrategy

Returns:

the result

Throws:

QueryEvaluationException

evaluateExclusiveGroup

public CloseableIteration<BindingSet,QueryEvaluationException> evaluateExclusiveGroup(ExclusiveGroup group,
                                                                                      BindingSet bindings)
                                                                               throws RepositoryException,
                                                                                      MalformedQueryException,
                                                                                      QueryEvaluationException

Specified by:

evaluateExclusiveGroup in class FederationEvalStrategy

Throws:

RepositoryException

MalformedQueryException

QueryEvaluationException