Lucene™ Features

Lucene offers powerful features through a simple API:

Scalable, High-Performance Indexing

• over 800GB/hour on modern hardware
• small RAM requirements -- only 1MB heap
• incremental indexing as fast as batch indexing
• index size roughly 20-30% the size of text indexed

Powerful, Accurate and Efficient Search Algorithms

• ranked searching -- best results returned first
• many powerful query types: phrase queries, wildcard queries, proximity queries, range queries and more
• fielded searching (e.g. title, author, contents)
• nearest-neighbor search for high-dimensionality vectors
• sorting by any field
• multiple-index searching with merged results
• allows simultaneous update and searching
• flexible faceting, highlighting, joins and result grouping
• fast, memory-efficient and typo-tolerant suggesters
• pluggable ranking models, including the Vector Space Model and Okapi BM25
• configurable storage engine (codecs)

Search performance of Apache Lucene is tracked in muliple places. Check out

• Mike McCandless' nightly benchmarks for Lucene for an historical view of Lucene's query performance, going back to 2011 for some queries
• Search Benchmark, the Game for a comparison of Lucene with other search engines

Cross-Platform Solution

• Available as Open Source software under the Apache License which lets you use Lucene in both commercial and Open Source programs
• 100%-pure Java
• Implementations in other programming languages available

Utility tools

• integrated desktop GUI tool (Luke): a utility for browsing, searching and maintaining indexes and documents. It can be started with "bin/luke.{sh|cmd}".