Book Image

Mastering Elasticsearch - Second Edition

Book Image

Mastering Elasticsearch - Second Edition

Overview of this book

Table of Contents (19 chapters)
Mastering Elasticsearch Second Edition
Credits
About the Author
Acknowledgments
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Index

Default Apache Lucene scoring explained


A very important part of the querying process in Apache Lucene is scoring. Scoring is the process of calculating the score property of a document in a scope of a given query. What is a score? A score is a factor that describes how well the document matched the query. In this section, we'll look at the default Apache Lucene scoring mechanism: the TF/IDF (term frequency/inverse document frequency) algorithm and how it affects the returned document. Knowing how this works is valuable when designing complicated queries and choosing which queries parts should be more relevant than the others. Knowing the basics of how scoring works in Lucene allows us to tune queries more easily and the results retuned by them to match our use case.

When a document is matched

When a document is returned by Lucene, it means that it matched the query we've sent. In such a case, the document is given a score. Sometimes, the score is the same for all the documents (like for...