As we have seen already, there are several prerequisites (for example, opening a directory, setting up an analyzer, and writing to index) to prepare an index for a search. Lucene provides the IndexReader
class to access a point-in-time view of an index. It means that you can concurrently write to an index, while an existing IndexReader
is reading without exposing any uncommitted data to the active IndexReader
. This is an important concept to keep in mind because this architecture allows the possibility of providing a seamless transition between index versions by opening a new IndexReader while the old IndexReader
is still servicing a search. The DirectoryReader
is a subclass of IndexReader
, which is the class that provides the facility to actually open a directory containing an index, and returns an IndexReader
. DirectoryReader also has a more optimized index opening method called openIfChanged
that will reuse the existing DirectoryReader for faster reopening of an...
Lucene 4 Cookbook
By :
Lucene 4 Cookbook
By:
Overview of this book
Table of Contents (16 chapters)
Lucene 4 Cookbook
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Free Chapter
Introducing Lucene
Analyzing Your Text
Indexing Your Data
Searching Your Indexes
Near Real-time Searching
Querying and Filtering Data
Flexible Scoring
Introducing Elasticsearch
Extending Lucene with Modules
Index
Customer Reviews