org.apache.lucene.facet (org.apache.lucene.facet)

Class Summary
Class	Description
DrillDownQuery	A `Query` for drill-down over facet categories.
DrillSideways	Computes drill down and sideways counts for the provided `DrillDownQuery`.
DrillSideways.ConcurrentDrillSidewaysResult<R>	Result of a concurrent drill sideways search, including the `Facets` and `TopDocs`.
DrillSideways.DrillSidewaysResult	Result of a drill sideways search, including the `Facets` and `TopDocs`.
FacetField	Add an instance of this to your `Document` for every facet label.
FacetQuery	A term `Query` over a `FacetField`.
FacetResult	Counts or aggregates for a single dimension.
Facets	Common base class for all facets implementations.
FacetsCollector	Collects hits for subsequent faceting.
FacetsCollector.MatchingDocs	Holds the documents that were matched in the `org.apache.lucene.index.LeafReaderContext`.
FacetsCollectorManager	A `CollectorManager` implementation which produces FacetsCollector and produces a merged FacetsCollector.
FacetsConfig	Records per-dimension configuration.
FacetsConfig.DimConfig	Holds the configuration for one dimension
LabelAndValue	Single label and its value, usually contained in a `FacetResult`.
LongValueFacetCounts	`Facets` implementation that computes counts for all unique long values, more efficiently counting small values (0-1023) using an int array, and switching to a `HashMap` for values above 1023.
MultiFacetQuery	A multi-terms `Query` over a `FacetField`.
MultiFacets	Maps specified dims to provided Facets impls; else, uses the default Facets impl.
RandomSamplingFacetsCollector	Collects hits for subsequent faceting, using sampling if needed.
TopOrdAndFloatQueue	Keeps highest results, first by largest float value, then tie break by smallest ord.
TopOrdAndFloatQueue.OrdAndValue	Holds a single entry.
TopOrdAndIntQueue	Keeps highest results, first by largest int value, then tie break by smallest ord.
TopOrdAndIntQueue.OrdAndValue	Holds a single entry.

Package org.apache.lucene.facet Description

Faceted search.

This module provides multiple methods for computing facet counts and value aggregations:

Taxonomy-based methods rely on a separate taxonomy index to map hierarchical facet paths to global int ordinals for fast counting at search time; these methods can compute counts ((FastTaxonomyFacetCounts, TaxonomyFacetCounts) aggregate long or double values TaxonomyFacetSumIntAssociations, TaxonomyFacetSumFloatAssociations, TaxonomyFacetSumValueSource. Add FacetField or AssociationFacetField to your documents at index time to use taxonomy-based methods.
Sorted-set doc values method does not require a separate taxonomy index, and computes counts based on sorted set doc values fields (SortedSetDocValuesFacetCounts). Add SortedSetDocValuesFacetField to your documents at index time to use sorted set facet counts.
Range faceting LongRangeFacetCounts, DoubleRangeFacetCounts compute counts for a dynamic numeric range from a provided org.apache.lucene.search.LongValuesSource (previously indexed numeric field, or a dynamic expression such as distance).

At search time you first run your search, but pass a FacetsCollector to gather all hits (and optionally, scores for each hit). Then, instantiate whichever facet methods you'd like to use to compute aggregates. Finally, all methods implement a common Facets base API that you use to obtain specific facet counts.

The various FacetsCollector.search(IndexSearcher, Query, int, Collector) utility methods are useful for doing an "ordinary" search (sorting by score, or by a specified Sort) but also collecting into a FacetsCollector for subsequent faceting.