## Package org.apache.lucene.index.pruning

Static Index Pruning Tools

See:
Description

Class Summary
CarmelTopKTermPruningPolicy: Pruning policy with a search quality parameterized guarantee - configuration of this policy allows to specify two parameters: k and ε such that:
CarmelTopKTermPruningPolicy.ByDocComparator
CarmelUniformTermPruningPolicy: Enhanced implementation of Carmel Uniform Pruning,
CarmelUniformTermPruningPolicy.ByDocComparator
PruningPolicy: General Definitions for Index Pruning, such as operations to be performed on field data.
PruningTool: A command-line tool to configure and run a `PruningReader` on an input index and produce a pruned output index using `IndexWriter.addIndexes(IndexReader...)`.
RIDFTermPruningPolicy: Implementation of `TermPruningPolicy` that uses "residual IDF" metric to determine the postings of terms to keep/remove, as defined in http://www.dc.fi.udc.es/~barreiro/publications/blanco_barreiro_ecir2007.pdf.
StorePruningPolicy: Pruning policy for removing stored fields from documents.

TermPruningPolicy

Policy for producing smaller index out of an input index, by examining its terms and removing from the index some or all of their data as follows: all terms of a certain field - see `TermPruningPolicy.pruneAllFieldPostings(String)` all data of a certain term - see `TermPruningPolicy.pruneTermEnum(TermEnum)` all positions of a certain term in a certain document - see #pruneAllPositions(TermPositions, Term) some positions of a certain term in a certain document - see #pruneSomePositions(int, int[], Term)

TFTermPruningPolicy: Policy for producing smaller index out of an input index, by removing postings data for those terms where their in-document frequency is below a specified threshold.

## Package org.apache.lucene.index.pruning Description

Static Index Pruning Tools

This package provides a framework for pruning an existing index into a smaller index while retaining visible search quality as much as possible.

An index can be pruned in several levels:

1. Remove stored data: see StorePruningPolicy
2. Remove terms data: see TermPruningPolicy

Pruning can be applied programmatically via a PruningReader or with the static tool PruningTool.