[SOLVED] Lucene is not finding results that are present in the index

Lucene is not finding results that are present in the index

I'm inspecting a Lucene index with Luke.

All documents have a field 'Title' and I would like to do a search for the search expression Title:Power, by which I want to find all documents with a title containing the word Power.

In Luke, I go to the tab "Search" and enter +Title:Power

When searching, there are no results. However, when I search by another field, I do find the document: +ContentType:MyContentType

In the column Title, I can clearly see the value of the document being: Power Quality Guide.

What could be the reasons I'm not finding this document when searching on Title?

Solution

There can be a number of reasons. Most common ones:

Title field could just be stored in the index but not indexed for search (Field.Store.YES, Field.Index.NO), unlike for the field for which you can find results (ContentType);
document(s) could be indexed using one analyzer but query is using a different one;
document is indexed using NOT_ANALYZED option which would store a field as a single term