I just realized that the problem is that the field needs to be indexed as well. Now it works. But I noticed that this only works in Lucene 9. Does not work in Lucene 8 (specifically 8.11.2). This must be new functionality in Lucene 9?
Thanks From: Solodin, Andrei (TR Technology) Sent: Saturday, November 5, 2022 1:07 PM To: java-user@lucene.apache.org Subject: Efficient sort on SortedDocValues Hello Lucene community, while looking into how to efficiently sort on a field value, I came across a couple of things that I don't quite understand. My assumption was that if I execute a search and sort on a SortedDocValues field, lucene would only iterate over the docs in the order of the field values or at least collect only competitive docs (docs that made it into the topN queue). Neither of those things seems to be happening. Instead, the iteration is happening in index order and all matched docs are collected. Looking at the code, I see that the optimizations are only possible if the index is sorted in the field order to begin with, which is not possible for our use case. We may have dozens of such fields in our index, thus there isn't any one field that can be used to sort the index. So I guess my question if what I am trying to achieve is possible? I tried to look though Solr codebase, but so far couldn't come up with anything. Code example is here https://pastebin.com/i05E2wZy . I am using 9.4.1. Thanks in advance. Andrei
