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

Class SameTermFilterOptimizer

java.lang.Object

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

All Implemented Interfaces:

QueryOptimizer

public class SameTermFilterOptimizer
extends Object
implements QueryOptimizer

A query optimizer that embeds Filters with SameTerm operators in statement patterns as much as possible. Operators like sameTerm(X, Y) are processed by renaming X to Y (or vice versa). Operators like sameTerm(X, ) are processed by assigning the URI to all occurring variables with name X.

Author:

Arjohn Kampman, James Leigh

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	SameTermFilterOptimizer.BindingSetAssignmentCollector
protected static class	SameTermFilterOptimizer.SameTermFilterVisitor
protected static class	SameTermFilterOptimizer.VarBinder
protected static class	SameTermFilterOptimizer.VarRenamer

Constructor Summary

Constructors

Constructor and Description
SameTermFilterOptimizer()

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 to the supplied query: variable assignments are inlined.

Methods inherited from class java.lang.Object

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

Constructor Detail

SameTermFilterOptimizer

public SameTermFilterOptimizer()

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 to the supplied query: variable assignments are inlined.

Specified by:

optimize in interface QueryOptimizer