java.lang.Object
org.apache.jena.sparql.engine.optimizer.reorder.ReorderTransformationSubstitution
org.apache.jena.sparql.engine.optimizer.reorder.ReorderFixedAlt
All Implemented Interfaces:
ReorderTransformation

public class ReorderFixedAlt extends ReorderTransformationSubstitution
Alternative fixed reorder function. This corresponds to the algorithm prior to Jena 2.11.2. It is susceptible to picking bad orders when there are lots of non-characteristic (non-selective) rdf:type triples.

The default "ReorderFixed" is better in most cases because it avoids "? rdf:type T" which can be very unselective. Being data independent, that is a guess. Consider using the stats matcher for detailed control.

  • Field Details

    • MultiTermSampleSize

      public static int MultiTermSampleSize
      The number of triples used for the base scale
    • MultiTermMax

      public static int MultiTermMax
      Maximum value for a match involving two terms.
    • matcher

      public static final StatsMatcher matcher
  • Constructor Details

    • ReorderFixedAlt

      public ReorderFixedAlt()
  • Method Details