com.hp.hpl.jena.sparql.engine.optimizer.reorder
Class ReorderFixed

java.lang.Object
  com.hp.hpl.jena.sparql.engine.optimizer.reorder.ReorderTransformationSubstitution
      com.hp.hpl.jena.sparql.engine.optimizer.reorder.ReorderFixed

All Implemented Interfaces:

ReorderTransformation

public class ReorderFixed
extends ReorderTransformationSubstitution

Fixed scheme for choosing based on the triple patterns, without looking at the data. It gives a weight to a triple, with more grounded terms being considered better. It weights against rdf:type because that can be very unselective (e.g. ?x rdf:type rdf:Resource)

Field Summary

static int

MultiTermSampleSize The number of triples used for the base scale

Fields inherited from class com.hp.hpl.jena.sparql.engine.optimizer.reorder.ReorderTransformationSubstitution

log

Constructor Summary

ReorderFixed()

Method Summary

double

weight(PatternTriple pt) Return the weight of the pattern, or -1 if no knowledge for it

Methods inherited from class com.hp.hpl.jena.sparql.engine.optimizer.reorder.ReorderTransformationSubstitution

reorder, reorderIndexes

Methods inherited from class java.lang.Object

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

Field Detail

MultiTermSampleSize

public static final int MultiTermSampleSize

The number of triples used for the base scale

See Also:

Constant Field Values

Constructor Detail

ReorderFixed

public ReorderFixed()

Method Detail

weight

public double weight(PatternTriple pt)

Description copied from class: ReorderTransformationSubstitution

Return the weight of the pattern, or -1 if no knowledge for it