Package org.apache.jena.sparql.algebra.optimize

Class TransformFilterPlacement

java.lang.Object

org.apache.jena.sparql.algebra.TransformCopy

org.apache.jena.sparql.algebra.optimize.TransformFilterPlacement

All Implemented Interfaces:

Transform

public class TransformFilterPlacement
extends TransformCopy

Rewrite an algebra expression to put filters as close to their bound variables.

Process BGP (whether triples or quads) is left as a separate step (but after this transform) because it can desirable to reorder the BGP before placing filters, or afterwards.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	TransformFilterPlacement.Placement

Field Summary

Fields inherited from class org.apache.jena.sparql.algebra.TransformCopy

COPY_ALWAYS, COPY_ONLY_ON_CHANGE

Constructor Summary

Constructors

Constructor	Description
TransformFilterPlacement()
TransformFilterPlacement(boolean includeBGPs)

Method Summary

Modifier and Type	Method	Description
static TransformFilterPlacement.Placement	filterPlacement$(ExprList exprs, Op op)	Operation exposes the filter placement mechanism so that investigation of filter placement issues can be done from outside this class.
Op	transform(OpFilter opFilter, Op x)
static Op	transform(ExprList exprs, Node graphNode, BasicPattern bgp)	Apply filter placement to a named graph BGP
static Op	transform(ExprList exprs, BasicPattern bgp)	Apply filter placement to a BGP

Methods inherited from class org.apache.jena.sparql.algebra.TransformCopy

transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform, transform

Methods inherited from class java.lang.Object

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

Constructor Detail

TransformFilterPlacement

public TransformFilterPlacement()

TransformFilterPlacement

public TransformFilterPlacement(boolean includeBGPs)

Method Detail

transform

public static Op transform(ExprList exprs,
                           BasicPattern bgp)

Apply filter placement to a BGP

transform

public static Op transform(ExprList exprs,
                           Node graphNode,
                           BasicPattern bgp)

Apply filter placement to a named graph BGP

filterPlacement$

public static TransformFilterPlacement.Placement filterPlacement$(ExprList exprs,
                                                                  Op op)

Operation exposes the filter placement mechanism so that investigation of filter placement issues can be done from outside this class. Do not use in application code : subject to removal or change at any time.

transform

public Op transform(OpFilter opFilter,
                    Op x)

Specified by:

transform in interface Transform

Overrides:

transform in class TransformCopy