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

Class QueryJoinOptimizer

java.lang.Object

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

All Implemented Interfaces:

QueryOptimizer

public class QueryJoinOptimizer
extends Object
implements QueryOptimizer

A query optimizer that re-orders nested Joins.

Author:

Arjohn Kampman, James Leigh

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	QueryJoinOptimizer.JoinVisitor

Field Summary

Fields

Modifier and Type	Field and Description
protected EvaluationStatistics	statistics

Constructor Summary

Constructors

Constructor and Description
QueryJoinOptimizer()
QueryJoinOptimizer(EvaluationStatistics statistics)

Method Summary

Modifier and Type	Method and Description
void	optimize(org.eclipse.rdf4j.query.algebra.TupleExpr tupleExpr, org.eclipse.rdf4j.query.Dataset dataset, org.eclipse.rdf4j.query.BindingSet bindings) Applies generally applicable optimizations: path expressions are sorted from more to less specific.

Methods inherited from class java.lang.Object

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

Field Detail

statistics

protected final EvaluationStatistics statistics

Constructor Detail

QueryJoinOptimizer

public QueryJoinOptimizer()

QueryJoinOptimizer

public QueryJoinOptimizer(EvaluationStatistics statistics)

Method Detail

optimize

public void optimize(org.eclipse.rdf4j.query.algebra.TupleExpr tupleExpr,
                     org.eclipse.rdf4j.query.Dataset dataset,
                     org.eclipse.rdf4j.query.BindingSet bindings)

Applies generally applicable optimizations: path expressions are sorted from more to less specific.

Specified by:

optimize in interface QueryOptimizer

Parameters:

tupleExpr -