Introduction
So far, we have explored Lucene's core functionalities and learned how to customize Lucene's core components. However, we haven't yet learnt any extension libraries that expand beyond the core features. In this chapter, we will discover the add-on features in Lucene and demonstrate how these features work and how to leverage these new functionalities effectively. We will cover the following features: spatial search, joins, faceting, grouping, autosuggest, and highlighting.