Book Image

Apache Solr Enterprise Search Server - Third Edition

By : David Smiley, Eric Pugh, Kranti Parisa, Matt Mitchell
Book Image

Apache Solr Enterprise Search Server - Third Edition

By: David Smiley, Eric Pugh, Kranti Parisa, Matt Mitchell

Overview of this book

<p>Solr Apache is a widely popular open source enterprise search server that delivers powerful search and faceted navigation features—features that are elusive with databases. Solr supports complex search criteria, faceting, result highlighting, query-completion, query spell-checking, relevancy tuning, geospatial searches, and much more.</p> <p>This book is a comprehensive resource for just about everything Solr has to offer, and it will take you from first exposure to development and deployment in no time. Even if you wish to use Solr 5, you should find the information to be just as applicable due to Solr's high regard for backward compatibility. The book includes some useful information specific to Solr 5.</p>
Table of Contents (19 chapters)
Apache Solr Enterprise Search Server Third Edition
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

The Stats component


The stats component calculates some mathematical statistics of fields in the index. The main requirement is that the field be indexed. The following statistics are computed over the non-null values (except missing which counts the nulls):

  • min: The smallest value

  • max: The largest value

  • sum: The sum

  • count: The quantity of non-null values accumulated in these statistics

  • missing: The quantity of records skipped due to missing values

  • sumOfSquares: The sum of the square of each value; this is probably the least useful and is used internally to compute stddev efficiently

  • mean: The average value

  • stddev: The standard deviation of the values

  • distinctValues: A list of all distinct (non-duplicating) values

  • countDistinct: The size of distinctValues

If you calculate stats on a string or date field, then only min, max, count, missing, distinctValues, and countDistinct are calculated. The distinctValues and countDistinct are only present if stats.calcdistinct is enabled.

Configuring the...