# Package org.apache.lucene.facet.taxonomy.directory

Taxonomy index implementation using on top of a Directory.

See: Description

- Interface Summary
  Interface | Description
  --- | ---
  DirectoryTaxonomyWriter.OrdinalMap | Mapping from old ordinal to new ordinals, used when merging indexes wit separate taxonomies.

- Class Summary
  Class | Description
  --- | ---
  DirectoryTaxonomyReader | A `TaxonomyReader` which retrieves stored taxonomy information from a `Directory`.
  DirectoryTaxonomyWriter | `TaxonomyWriter` which uses a `Directory` to store the taxonomy information on disk, and keeps an additional in-memory cache of some or all categories.
  DirectoryTaxonomyWriter.DiskOrdinalMap | `DirectoryTaxonomyWriter.OrdinalMap` maintained on file system
  DirectoryTaxonomyWriter.MemoryOrdinalMap | `DirectoryTaxonomyWriter.OrdinalMap` maintained in memory
  ParallelTaxonomyArrays | Returns 3 arrays for traversing the taxonomy: `parents`: `parents[i]` denotes the parent of category ordinal `i`. `children`: `children[i]` denotes the youngest child of category ordinal `i`.

## Package org.apache.lucene.facet.taxonomy.directory Description

Taxonomy index implementation using on top of a Directory.

Copyright © 2000-2013 Apache Software Foundation. All Rights Reserved.