Module org.apache.jena.arq
Class ReorderFixedAlt
java.lang.Object
org.apache.jena.sparql.engine.optimizer.reorder.ReorderTransformationSubstitution
org.apache.jena.sparql.engine.optimizer.reorder.ReorderFixedAlt
- All Implemented Interfaces:
ReorderTransformation
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.
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Field Summary
Modifier and TypeFieldDescriptionstatic final StatsMatcher
static int
Maximum value for a match involving two terms.static int
The number of triples used for the base scaleFields inherited from class org.apache.jena.sparql.engine.optimizer.reorder.ReorderTransformationSubstitution
log
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Constructor Summary
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Method Summary
Methods inherited from class org.apache.jena.sparql.engine.optimizer.reorder.ReorderTransformationSubstitution
reorder, reorderIndexes
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Field Details
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MultiTermSampleSize
public static int MultiTermSampleSizeThe number of triples used for the base scale -
MultiTermMax
public static int MultiTermMaxMaximum value for a match involving two terms. -
matcher
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Constructor Details
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ReorderFixedAlt
public ReorderFixedAlt()
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Method Details
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weight
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