Class ProjectionRemovalOptimizer
- java.lang.Object
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- org.eclipse.rdf4j.query.algebra.evaluation.optimizer.ProjectionRemovalOptimizer
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- org.eclipse.rdf4j.query.algebra.evaluation.impl.ProjectionRemovalOptimizer
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- All Implemented Interfaces:
QueryOptimizer
@Deprecated(forRemoval=true, since="4.1.0") public class ProjectionRemovalOptimizer extends ProjectionRemovalOptimizer implements QueryOptimizer
Deprecated, for removal: This API element is subject to removal in a future version.since 4.1.0. UseProjectionRemovalOptimizer
instead.If a projection node in the algebra does not contribute or change the results it can be removed from the tree.For example
SELECT ?s ?p ?o WHERE {?s ?p ?o }
Does not need a projection as the inner statement pattern returns the same result.While
* SELECT ?s ?p WHERE {?s ?p ?o }
Does as the statement pattern has one more variable in use than the projection.Note: this optimiser should run after optimisations ran that depend on Projections. e.g.
- Author:
- Jerven Bolleman
- See Also:
UnionScopeChangeOptimizer
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Constructor Summary
Constructors Constructor Description ProjectionRemovalOptimizer()
Deprecated, for removal: This API element is subject to removal in a future version.
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Method Summary
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Methods inherited from class org.eclipse.rdf4j.query.algebra.evaluation.optimizer.ProjectionRemovalOptimizer
optimize
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Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Methods inherited from interface org.eclipse.rdf4j.query.algebra.evaluation.QueryOptimizer
optimize
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