# Lucene 10.0.0 misc API

# Misc Tools

The misc package has various tools for splitting/merging indices, changing norms, finding high freq terms, and others.

## DirectIODirectory

`DirectIODirectory` is a Directory implementation that bypasses the OS's buffer cache (using direct IO) for any IndexInput and IndexOutput used during merging of segments larger than a specified size (default 10 MB). This avoids evicting hot pages that are still in-use for searching, keeping search more responsive while large merges run.

See this blog post for details.

Packages
Package
Description
org.apache.lucene.misc
Miscellaneous Lucene utilities that don't really fit anywhere else.
org.apache.lucene.misc.document
Misc extensions of the Document/Field API.
org.apache.lucene.misc.index
Misc index tools and index support.
org.apache.lucene.misc.search
Misc search implementations.
org.apache.lucene.misc.store
Misc Directory implementations.
org.apache.lucene.misc.util
Memory Tracker interface which allows defining custom collector level memory trackers
org.apache.lucene.misc.util.fst
Misc FST classes.