Hi David, Yes we have migrated most of the result grouping use case to "Collapse & Expand" as the official solr doc suggested, there are just a few that we can't really migrate yet.
I'll file a jira with more details and submit a PR soon Thanks, Yue On Sat, Apr 5, 2025 at 12:37 PM David Smiley <dsmi...@apache.org> wrote: > Maybe not a helpful response but I want to say anyway that you should > consider "Collapse & Expand" before result grouping. It's generally more > efficient, code details are better encapsulated (which I care about, as a > maintainer). However, result grouping works on distributed search (shards) > when a group may span shards. > > If you find a perf bug; PR welcome! > > On Sat, Apr 5, 2025 at 6:49 AM Yue Yu <yue...@bloomreach.com> wrote: > > > Hi All, > > > > When running vector search with grouping in multi-shard setting, the > > KnnFloatVectorQuery is executed (2+rows) times. > > > > I've observed that Qtime grows linearly when I increase "rows" number > > > > The culprit is this function call in > > > > > https://github.com/apache/solr/blob/main/solr/core/src/java/org/apache/solr/search/grouping/distributed/command/TopGroupsFieldCommand.java#L202 > > > > if (needScores) { > > for (GroupDocs<?> group : topGroups.groups) { > > TopFieldCollector.populateScores(group.scoreDocs, searcher, query); > > } > > } > > > > Where > > > > > https://github.com/apache/lucene/blob/main/lucene/core/src/java/org/apache/lucene/search/TopFieldCollector.java#L403 > > does > > > > final Weight weight = searcher.createWeight(searcher.rewrite(query), > > ScoreMode.COMPLETE, 1); > > > > Here, if the query is KnnFloatVectorQuery, *searcher.rewrite(query) *will > > execute the same vector search for each topGroups.groups > > > > a simple fix could be moving *searcher.rewrite(query) *out of the > > topGroups.groups loop. Thoughts? > > > > Best, > > > > Yue > > >
