Package 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	Description
protected class	QueryJoinOptimizer.JoinVisitor	Deprecated. This class is protected for historic reasons only, and will be made private in a future major release.

Field Summary

Fields

Modifier and Type	Field	Description
protected final EvaluationStatistics	statistics

Constructor Summary

Constructors

Constructor	Description
QueryJoinOptimizer()
QueryJoinOptimizer(EvaluationStatistics statistics)

Method Summary

Modifier and Type	Method	Description
void	optimize(TupleExpr tupleExpr, Dataset dataset, 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 Details

statistics

protected final EvaluationStatistics statistics

Constructor Details

QueryJoinOptimizer

public QueryJoinOptimizer()

QueryJoinOptimizer

public QueryJoinOptimizer(EvaluationStatistics statistics)

Method Details

optimize

public void optimize(TupleExpr tupleExpr,
 Dataset dataset,
 BindingSet bindings)

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

Specified by:

optimize in interface QueryOptimizer

Parameters:

tupleExpr -