Book Image

Apache Solr Beginner's Guide

By : Alfredo Serafini
Book Image

Apache Solr Beginner's Guide

By: Alfredo Serafini

Overview of this book

<p>With over 40 billion web pages, the importance of optimizing a search engine's performance is essential.<br /><br />Solr is an open source enterprise search platform from the Apache Lucene project. Full-text search, faceted search, hit highlighting, dynamic clustering, database integration, and rich document handling are just some of its many features. Solr is highly scalable thanks to its distributed search and index replication.<br /><br />Solr is written in Java and runs as a standalone full-text search server within a servlet container such as Apache Tomcat or Jetty. Solr uses the Lucene Java search library at its core for full-text indexing and search, and has REST-like HTTP/XML and JSON APIs that make it usable with most popular programming languages. Solr's powerful external configuration allows it to be tailored to many types of application without Java coding, and it has a plugin architecture to support more advanced customization.<br /><br />With Apache Solr Beginner's Guide you will learn how to configure your own search engine experience. Using real data as an example, you will have the chance to start writing step-by-step, simple, real-world configurations and understand when and where to adopt this technology.<br /><br />Apache Solr Beginner's Guide will start by letting you explore a simple search over real data. You will then go through a step-by-step description that gives you the chance to explore several practical features. At the end of the book you will see how Solr is used in different real-world contexts.<br /><br />Using data from public domains like DBpedia, you will define several different configurations, exploring some of the most interesting Solr features, such as faceted search and navigation, auto-suggestion, and rich document indexing. You will see how to configure different analysers for handling different data types, without programming.<br /><br />You will learn the basics of Solr, focusing on real-world examples and practical configurations.</p>
Table of Contents (19 chapters)
Apache Solr Beginner's Guide
Credits
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Index

Time for action – searching for all documents with pagination


When performing a query, we need to remember we are potentially asking for a huge number of documents. Let's observe how to manage partial results using pagination:

  1. For example, think about the q=*:* query that we saw in previous examples. it was used for asking all the documents, without a specific criteria. In a case like this, in order to avoid problems with resources, Solr will actually send us only the first results, as defined by a parameter in the configuration. The default number of returned results will be 10. So, we need to be able to ask for a second group of results, a third, and so on and on. This is what is generally called a pagination of results, similarly as for scenarios involving SQL.

  2. The command is executed as follows:

    >> curl -X GET "http://localhost:8983/solr/paintings/select?q=*:*&start=0&rows=0&wt=json&indent=true"
    
  3. We should obtain a result similar to the following screenshot. The number...