Properly used, an SQL database index can be so effective that it might seem like magic. But the following series of exercises will show that underneath, the logic of most SQL indexes---and wielding them correctly---is quite straightforward.
Apache Lucene is a powerful Java library used for implementing full-text search on a corpus of text. With its wide array of configuration options and customizability, it is possible to tune Apache Lucene specifically to the corpus at hand - improving both search quality and query capability.
This article gives us a glimpse of the simplicity and ease of customization of the Apache Lucene analysis pipeline.