# Uses of Class
org.apache.lucene.index.FilterMergePolicy

Packages that use FilterMergePolicy
Package
Description
org.apache.lucene.index
Code to maintain and access indices.

- ## Uses of FilterMergePolicy in org.apache.lucene.index

  Subclasses of FilterMergePolicy in org.apache.lucene.index
  Modifier and Type
  Class
  Description
  `class`
  `OneMergeWrappingMergePolicy`
  A wrapping merge policy that wraps the `MergePolicy.OneMerge` objects returned by the wrapped merge policy.
  `final class`
  `SoftDeletesRetentionMergePolicy`
  This `MergePolicy` allows to carry over soft deleted documents across merges.
  `class`
  `UpgradeIndexMergePolicy`
  This `MergePolicy` is used for upgrading all existing segments of an index when calling `IndexWriter.forceMerge(int)`.