Class QueryJoinOptimizer
java.lang.Object
org.eclipse.rdf4j.query.algebra.evaluation.optimizer.QueryJoinOptimizer
- All Implemented Interfaces:
QueryOptimizer
- Direct Known Subclasses:
QueryJoinOptimizer
A query optimizer that re-orders nested Joins.
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Nested Class Summary
Nested Classes -
Field Summary
Fields -
Constructor Summary
ConstructorsConstructorDescriptionQueryJoinOptimizer
(EvaluationStatistics statistics) QueryJoinOptimizer
(EvaluationStatistics statistics, boolean trackResultSize) -
Method Summary
Modifier and TypeMethodDescriptionprivate static int
getJoinSize
(Set<String> currentListNames, Set<String> names) private static int
getUnionSize
(Set<String> currentListNames, Set<String> candidateBindingNames) private static boolean
hasCachedCardinality
(TupleExpr tupleExpr) void
optimize
(TupleExpr tupleExpr, Dataset dataset, BindingSet bindings) Applies generally applicable optimizations: path expressions are sorted from more to less specific.
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Field Details
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statistics
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trackResultSize
private final boolean trackResultSize
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Constructor Details
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QueryJoinOptimizer
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QueryJoinOptimizer
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Method Details
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optimize
Applies generally applicable optimizations: path expressions are sorted from more to less specific.- Specified by:
optimize
in interfaceQueryOptimizer
- Parameters:
tupleExpr
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getUnionSize
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getJoinSize
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hasCachedCardinality
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