Hi, On Wed, Jun 19, 2013 at 12:16 AM, Sriram Sankar <san...@gmail.com> wrote: > Is it possible to do this more efficiently using a merge sort? Assuming > the individual segments are already sorted, is there a wrapper that I can > use where I can pass the same sorting function? I'm guessing the > SlowCompositeReaderWrapper does not assume that the individual segments are > already sorted and therefore would repeat the work?
Given that online sorting is rather new to Lucene, we tried to keep it simple. Merging segments in parallel by maintaining a priority queue is totally doable and is probably one of the next steps for online sorting but it would require some non-trivial work to reimplement merging for all formats (postings lists especially) and to be able to plug a custom SegmentMerger into the IndexWriter. For now, we just make sure that sorting a SlowCompositeReaderWrapper which wraps several sorted segments is faster than sorting a random AtomicReader by using TimSort to compute the mapping between the old and the new doc IDs and to sort all individual postings lists. -- Adrien --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
