Sorry for not updating blog such a long time. May be I was just too lazy to do it. But I will try to not to be so lazy from nowon ;)
Lucene is a framework which allows you to store some data that cab be indexed so that fast search operations can be performed on it. This data can actually from from any source like file system, Database, http etc.
Data is stored in a "Document" form within by Lucene. Its is programmer's responsibility to get the data and create documents. Lucene takes responsibility to index it and make them searchable.
Was reading on some articles to confirm the Lucene implementation in my Grails app is proper or not. Came across following few very good links for starters.