Book Image

Apache Solr for Indexing Data

Book Image

Apache Solr for Indexing Data

Overview of this book

Apache Solr is a widely used, open source enterprise search server that delivers powerful indexing and searching features. These features help fetch relevant information from various sources and documentation. Solr also combines with other open source tools such as Apache Tika and Apache Nutch to provide more powerful features. This fast-paced guide starts by helping you set up Solr and get acquainted with its basic building blocks, to give you a better understanding of Solr indexing. You’ll quickly move on to indexing text and boosting the indexing time. Next, you’ll focus on basic indexing techniques, various index handlers designed to modify documents, and indexing a structured data source through Data Import Handler. Moving on, you will learn techniques to perform real-time indexing and atomic updates, as well as more advanced indexing techniques such as de-duplication. Later on, we’ll help you set up a cluster of Solr servers that combine fault tolerance and high availability. You will also gain insights into working scenarios of different aspects of Solr and how to use Solr with e-commerce data. By the end of the book, you will be competent and confident working with indexing and will have a good knowledge base to efficiently program elements.
Table of Contents (18 chapters)
Apache Solr for Indexing Data
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Tokenizers


The function of a tokenizer is to break input text into tokens, where each token is a stream of characters in the text. You configure a tokenizer for a text field type in schema.xml with a <tokenizer> element, which is a child of <analyzer>, like this for example:

<fieldType name="text" class="solr.TextField">
    <analyzer type="index">
        <tokenizer class="solr.StandardTokenizerFactory"/>
        <filter class="solr.StandardFilterFactory"/>
    </analyzer>
</fieldType>

In the preceding example, you can see that a class attribute names a factory class that will instantiate a tokenizer object when needed. Tokenizer factory classes implement org.apache.solr.analysis.TokenizerFactory. You can pass arguments to tokenizer factories by setting attributes in the <tokenizer> element. Here is an example of this:

<fieldType name="semicolonDelimited" class="solr.TextField">
  <analyzer type="query">
  <tokenizer class...