[LUCENE-528] Optimization for IndexWriter.addIndexes()

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Component/s: core/index
• Lucene Fields: Patch Available
• Assignee: Yonik Seeley
• Reporter: Steven Tamm
• Created: 22/Mar/06 06:14
• Updated: 28/Aug/22 11:26
• Resolved: 26/Oct/06 22:56

Description

One big performance problem with IndexWriter.addIndexes() is that it has to optimize the index both before and after adding the segments. When you have a very large index, to which you are adding batches of small updates, these calls to optimize make using addIndexes() impossible. It makes parallel updates very frustrating.

Here is an optimized function that helps out by calling mergeSegments only on the newly added documents. It will try to avoid calling mergeSegments until the end, unless you're adding a lot of documents at once.

I also have an extensive unit test that verifies that this function works correctly if people are interested. I gave it a different name because it has very different performance characteristics which can make querying take longer.