Lucene.NET - 无法使用IndexWriter删除文档

Question

I'm taking over a project so I'm still learning this. The project uses Lucence.NET. I also have no idea if this piece of functionality is correct or not. Anyway, I am instantiating:

var writer = new IndexWriter(directory, analyzer, false);

For specific documents, I'm calling:

writer.DeleteDocuments(new Term(...));

In the end, I'm calling the usual writer.Optimize(), writer.Commit(), and writer.Close().

The field in the Term object is a Guid, converted to a string (.ToString("D")), and is stored in the document, using Field.Store.YES, and Field.Index.NO.

However, with these settings, I cannot seem to delete these documents. The goal is to delete, then add the updated versions, so I'm getting duplicates of the same document. I can provide more code/explanation if needed. Any ideas? Thanks.

Answer 1

The field must be indexed. If a field is not indexed, its terms will not show up in enumeration.

Answer 2

I don't think there is anything wrong with how you are handling the writer.

It sounds as if the term you are passing to DeleteDocuments is not returning any documents. Have you tried to do a query using the same term to see if it returns any results?

Also, if your goal is to simple recreate the document, you can call UpdateDocument:

//     Updates a document by first deleting the document(s) containing term and
//     then adding the new document. The delete and then add are atomic as seen
//     by a reader on the same index (flush may happen only after the add).  NOTE:
//     if this method hits an OutOfMemoryError you should immediately close the
//     writer. See above for details.

You may also want to check out SimpleLucene (http://simplelucene.codeplex.com) - it makes it a bit easier to do basic Lucene tasks.

[Update] Not sure how I missed it but @Shashikant Kore is correct, you need to make sure the field is indexed otherwise your term query will not return anything.