I noticed that you have asked this same question in lucene-user list.

You asked there: "While searching how the index will map to the documents in database since we
have documents stored in different tables in database?
".

You have to store the document id to the index. And when you search your index, you get the document id among other things. And when you want to view one document from the search result, you can find right document with the document id. :)

--Jouni