Class FilterOptimizer

java.lang.Object
org.eclipse.rdf4j.query.algebra.evaluation.optimizer.FilterOptimizer
org.eclipse.rdf4j.query.algebra.evaluation.impl.FilterOptimizer
All Implemented Interfaces:
QueryOptimizer
@Deprecated(forRemoval=true, since="4.1.0") public class FilterOptimizer extends FilterOptimizer implements QueryOptimizer
Deprecated, for removal: This API element is subject to removal in a future version.
since 4.1.0. Use FilterOptimizer instead.
Optimizes a query model by pushing Filters as far down in the model tree as possible.

To make the first optimization succeed more often it splits filters which contains And conditions. SELECT * WHERE { ?s ?p ?o . ?s ?p ?o2 . FILTER(?o > '2'^^xsd:int invalid input: '&'invalid input: '&' ?o2 invalid input: '<' '4'^^xsd:int) } May be more efficient when decomposed into SELECT * WHERE { ?s ?p ?o . FILTER(?o > '2'^^xsd:int) ?s ?p ?o2 . FILTER(?o2 invalid input: '<' '4'^^xsd:int) }

Then it optimizes a query model by merging adjacent Filters. e.g. SELECT * WHERE { ?s ?p ?o . FILTER(?o > 2) . FILTER(?o invalid input: '<' 4) . } may be merged into SELECT * WHERE { ?s ?p ?o . FILTER(?o > 2 invalid input: '&'invalid input: '&' ?o invalid input: '<' 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.

  • Constructor Details

    • FilterOptimizer

      public FilterOptimizer()
      Deprecated, for removal: This API element is subject to removal in a future version.