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Lucene 4 Cookbook

Lucene 4 Cookbook

By : Edwood Ng, Vineeth Mohan
3.2 (5)
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Lucene 4 Cookbook

Lucene 4 Cookbook

3.2 (5)
By: Edwood Ng, Vineeth Mohan

Overview of this book

This book is for software developers who are new to Lucene and who want to explore the more advanced topics to build a search engine. Knowledge of Java is necessary to follow the code samples. You will learn core concepts, best practices, and also advanced features, in order to build an effective search application.
Table of Contents (11 chapters)
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10
Index

Using the DirectoryReader to open index in Near Real-Time


First of all, let's cover the basics. The DirectoryReader attribute that we are already familiar with actually allows you to open an index with IndexWriter with the option to include uncommitted changes. This gives you a point-in-time snapshot of the index, including any updates that are not committed yet. In a typical search application, IndexSearcher would need to be reopened periodically anyway to expose recent updates. This feature provides an option to immediately expose index updates without waiting for IndexWriter to commit first. Potentially, the search application may have to maintain multiple IndexSearchers as depicted in the following diagram:

One use case for this feature is that users may want to review their recently submitted content to see how it ranked in search results. To provide the most up-to-date index after a user submits an update, we can open a new IndexSearcher with uncommitted changes to serve queries while...

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