Matt Williams has a quick post to his blog about using the combination of PHP and Apache's Solr to more powerful searching than something like a MySQL fulltext index can give you.

When data sets get large and MySQL database querying to search become too load heavy and slow, full indexing is required. Several solutions are available but in this article I will be demonstrating the Apache foundations Solr Java Lucene implementation. For this a Java build will be required. Linux or Mac is less of a problem but for windows I use the Apache Tomcat server.

He shows ho to use the Solr PHP interface to make the connection to the server, ping it to be sure the connection is working and, based on the schema and search information, return a set of results in a PHP object.