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| <html> |
| <head> |
| <title>faceted search</title> |
| </head> |
| <body> |
| <h1>faceted search</h1> |
| <p> |
| This module provides multiple methods for computing facet counts and |
| value aggregations: |
| <ul> |
| <li> 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 |
| (({@link org.apache.lucene.facet.taxonomy.FastTaxonomyFacetCounts}, {@link |
| org.apache.lucene.facet.taxonomy.TaxonomyFacetCounts}) aggregate long or double values {@link |
| org.apache.lucene.facet.taxonomy.TaxonomyFacetSumIntAssociations}, {@link |
| org.apache.lucene.facet.taxonomy.TaxonomyFacetSumFloatAssociations}, {@link |
| org.apache.lucene.facet.taxonomy.TaxonomyFacetSumValueSource}. Add {@link org.apache.lucene.facet.FacetField} or |
| {@link org.apache.lucene.facet.taxonomy.AssociationFacetField} to your documents at index time |
| to use taxonomy-based methods. |
| |
| <li> Sorted-set doc values method does not require a separate |
| taxonomy index, and computes counts based on sorted set doc |
| values fields ({@link org.apache.lucene.facet.sortedset.SortedSetDocValuesFacetCounts}). Add |
| {@link org.apache.lucene.facet.sortedset.SortedSetDocValuesFacetField} to your documents at |
| index time to use sorted set facet counts. |
| |
| <li> Range faceting {@link org.apache.lucene.facet.range.LongRangeFacetCounts}, {@link |
| org.apache.lucene.facet.range.DoubleRangeFacetCounts} compute counts for a dynamic numeric |
| range from a provided {@link org.apache.lucene.queries.function.ValueSource} (previously indexed |
| numeric field, or a dynamic expression such as distance). |
| </ul> |
| </p> |
| <p> |
| At search time you first run your search, but pass a {@link |
| org.apache.lucene.facet.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 |
| {@link org.apache.lucene.facet.Facets} base API that you use to obtain specific facet |
| counts. |
| </p> |
| <p> |
| The various {@link org.apache.lucene.facet.FacetsCollector#search} utility methods are |
| useful for doing an "ordinary" search (sorting by score, or by a |
| specified Sort) but also collecting into a {@link org.apache.lucene.facet.FacetsCollector} for |
| subsequent faceting. |
| </p> |
| </body> |
| </html> |
