org.apache.lucene.facet.sampling
Class SamplingWrapper
java.lang.Object
org.apache.lucene.facet.search.FacetsAccumulator
org.apache.lucene.facet.search.StandardFacetsAccumulator
org.apache.lucene.facet.sampling.SamplingWrapper
public class SamplingWrapper
- extends StandardFacetsAccumulator
Wrap any Facets Accumulator with sampling.
Note: Sampling accumulation (Accumulation over a sampled-set of the results),
does not guarantee accurate values for
FacetResult.getNumValidDescendants()
.
- WARNING: This API is experimental and might change in incompatible ways in the next release.
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
SamplingWrapper
public SamplingWrapper(StandardFacetsAccumulator delegee,
Sampler sampler)
accumulate
public List<FacetResult> accumulate(ScoredDocIDs docids)
throws IOException
- Overrides:
accumulate
in class StandardFacetsAccumulator
- Throws:
IOException
getComplementThreshold
public double getComplementThreshold()
- Description copied from class:
StandardFacetsAccumulator
- Returns the complement threshold.
- Overrides:
getComplementThreshold
in class StandardFacetsAccumulator
- See Also:
StandardFacetsAccumulator.setComplementThreshold(double)
setComplementThreshold
public void setComplementThreshold(double complementThreshold)
- Description copied from class:
StandardFacetsAccumulator
- Set the complement threshold.
This threshold will dictate whether the complements optimization is applied.
The optimization is to count for less documents. It is useful when the same
FacetSearchParams are used for varying sets of documents. The first time
complements is used the "total counts" are computed - counting for all the
documents in the collection. Then, only the complementing set of documents
is considered, and used to decrement from the overall counts, thereby
walking through less documents, which is faster.
For the default settings see StandardFacetsAccumulator.DEFAULT_COMPLEMENT_THRESHOLD
.
To forcing complements in all cases pass StandardFacetsAccumulator.FORCE_COMPLEMENT
.
This is mostly useful for testing purposes, as forcing complements when only
tiny fraction of available documents match the query does not make sense and
would incur performance degradations.
To disable complements pass StandardFacetsAccumulator.DISABLE_COMPLEMENT
.
- Overrides:
setComplementThreshold
in class StandardFacetsAccumulator
- Parameters:
complementThreshold
- the complement threshold to set- See Also:
StandardFacetsAccumulator.getComplementThreshold()
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