Sphinx
Sphinx是一个基于SQL的全文检索引擎，可以结合MySQL,PostgreSQL做全文搜索，它可以提供比数据库本身更专业的搜索功能，使得应用程序更容易实现专业化的全文检索。Sphinx特别为一些脚本语言设计搜索API接口，如PHP,Python,Perl,Ruby等，同时为 MySQL也设计了一个存储引擎插件。
Sphinx的特性：
- 高速索引 (在新款CPU上,近10 MB/秒);
- 高速搜索 (2-4G的文本量中平均查询速度不到0.1秒);
- 高可用性 (单CPU上最大可支持100 GB的文本,100M文档);
- 提供良好的相关性排名
- 支持分布式搜索;
- 提供文档摘要生成;
- 提供从MySQL内部的插件式存储引擎上搜索
- 支持布尔,短语, 和近义词查询;
- 支持每个文档多个全文检索域(默认最大32个);
- 支持每个文档多属性;
- 支持断词;
- 支持单字节编码与UTF-8编码;
Sphinx is a full-text search engine, distributed under GPL version 2. Commercial license is also available for embedded use.
Generally, it's a standalone search engine, meant to provide fast, size-efficient and relevant fulltext search functions to other applications. Sphinx was specially designed to integrate well with SQL databases and scripting languages. Currently built-in data sources support fetching data either via direct connection to MySQL or PostgreSQL, or using XML pipe mechanism (a pipe to indexer in special XML-based format which Sphinx recognizes).
As for the name, Sphinx is an acronym which is officially decoded as SQL Phrase Index. Yes, I know about CMU's Sphinx project.
Key features
* high indexing speed (upto 10 MB/sec on modern CPUs)
* high search speed (avg query is under 0.1 sec on 2-4 GB text collections)
* high scalability (upto 100 GB of text, upto 100 M documents on a single CPU)
* supports distributed searching (since v.0.9.6)
* supports MySQL natively (MyISAM and InnoDB tables are both supported)
* supports phrase searching
* supports phrase proximity ranking, providing good relevance
* supports English and Russian stemming
* supports any number of document fields (weights can be changed on the fly)
* supports document groups
* supports stopwords
* supports different search modes ("match all", "match phrase" and "match any" as of v.0.9.5)
* generic XML interface which greatly simplifies custom integration
* pure-PHP (ie. NO module compiling etc) search client API
