Committed changes visibility in Lucene. Best practices

Question

I'm using Lucene 3.0.3. I've made a Spring bean aiming to encapsulate all operations on the same index.

public class IndexOperations {

    private IndexWriter writer;
    private IndexReader reader;
    private IndexSearcher searcher;

    public void init() {...}
    public void destroy() {...}

    public void save(Document d) {...}
    public void delete(Document d) {...}
    public List<Document> list() {...}

}

In order to permit fast changes and searches, I thought leaving writer, reader and searcher open could be a good idea. But the problem is that commited changes on writer can't be seen by readers until reopen. And this operation can be costly, so maybe is not a good idea for fast searches.

What would be the best approach for this typical scenario?

Answer 1

You should keep the writer always open, but don't persist the reader/searcher. When you need a searcher just do IndexSearcher srch = new IndexSearcher(writer.getReader()); This way the searcher will get the most recent changes, even if they aren't flushed to disk yet (giving you the best of both worlds).