Class FilterOptimizer
- java.lang.Object
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- org.eclipse.rdf4j.query.algebra.evaluation.impl.FilterOptimizer
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- All Implemented Interfaces:
QueryOptimizer
public class FilterOptimizer extends Object implements QueryOptimizer
Optimizes a query model by pushingFilter
s as far down in the model tree as possible. To make the first optimization succeed more often it splits filters which containsAnd
conditions.SELECT * WHERE { ?s ?p ?o . ?s ?p ?o2 . FILTER(?o > '2'^^xsd:int && ?o2 < '4'^^xsd:int) }
May be more efficient when decomposed intoSELECT * WHERE { ?s ?p ?o . FILTER(?o > '2'^^xsd:int) ?s ?p ?o2 . FILTER(?o2 < '4'^^xsd:int) }
Then it optimizes a query model by merging adjacentFilter
s. e.g.SELECT * WHERE { ?s ?p ?o . FILTER(?o > 2) . FILTER(?o < 4) . }
may be merged intoSELECT * WHERE { ?s ?p ?o . FILTER(?o > 2 && ?o < 4) . }
This optimization allows for sharing evaluation costs in the future and removes an iterator. This is done as a second step to not break the first optimization. In the case that the splitting was done but did not help it is now undone.- Author:
- Arjohn Kampman, Jerven Bolleman
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Nested Class Summary
Nested Classes Modifier and Type Class Description protected static class
FilterOptimizer.DeMergeFilterFinder
protected static class
FilterOptimizer.FilterFinder
protected static class
FilterOptimizer.FilterRelocator
protected static class
FilterOptimizer.MergeFilterFinder
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Constructor Summary
Constructors Constructor Description FilterOptimizer()
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
optimize(TupleExpr tupleExpr, Dataset dataset, BindingSet bindings)
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Method Detail
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optimize
public void optimize(TupleExpr tupleExpr, Dataset dataset, BindingSet bindings)
- Specified by:
optimize
in interfaceQueryOptimizer
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