Here's a good article from Zend showing you how to create your own
search engine using Zend_Search_Lucene ( part of the Zend Framework).
"One of the features that sets the Zend Framework apart from the others
is the inclusion of a decent search module. Zend_Search_Lucene is a php
port of the Apache Lucene project, a full-text search engine framework.
Zend_Search_Lucene promises a simple way to add search functionality to
an application without requiring additional php extensions or even a
Zend_Search_Lucene overcomes the usual limitations of relational
databases with features such as fast indexing, ranked result sets, a
powerful but simple query syntax, and the ability to index multiple
fields. Better still, a Zend_Search_Lucene index can live happily
alongside your relational database to provide fast searching but
without duplicating the effort of storing all of your data twice. In
this tutorial, I'll show you how to use Zend_Search_Lucene to index
and search some RSS feeds."
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