I'm not against deprecating "Result Grouping" per-se, but it has one huge advantage over Collapse/Expand: Result Grouping is the only approach that supports multi-shard.
Should we come up with a plan for that and other gaps before we deprecate Result Grouping? Deprecating the feature before there's even a path to removing it might spook users unnecessarily for whom "Result Grouping" is the only legitimate option. Best, Jason On Thu, Jan 9, 2025 at 4:40 PM David Smiley <dsmi...@apache.org> wrote: > > Solr has supported Result Grouping[1] for a long time but has mostly been > duplicative with Collapse & Expand[2]. At the start of the RG docs, > there's this notice which I wrote many (10?) years ago: > > > Prefer Collapse & Expand instead > > Solr’s Collapse and Expand Results feature is newer and mostly overlaps > with Result Grouping. > > There are features unique to both, and they have different performance > characteristics. > > That said, in most cases Collapse and Expand is preferable to Result > Grouping. > > I wrote that note into the guide to shift our users to the better > alternative so that we could someday more formally actually deprecate then > remove Result Grouping. > > I was motivated by a strong distaste, really disgust, at the complexity > that it had, starting with QueryComponent (ground zero for that complexity) > but leaks to many places elsewhere, which is the real indication of a > complex thing. QC got a little organizational love (thanks Christine) once > but it doesn't change my opinion. Collapse & Expand then came along and > showed an alternative that is superior from a maintenance / design point of > view (thanks Joel), and typically performs better too. A colleague noticed > the same complexity and actually ripped it out of our fork, touching some > 78 files in the process, including removing a dependency on > lucene-grouping. I'd be happy to post a draft PR of what that looks like > if it would help motivate us to pursue this. > > After polling our users for understanding why they have not moved on, I'd > like to take the next step of deprecating it along with a log message that > would occur on first use via our DeprecationLog mechanism. It's premature > to discuss deleting the code. I'm worried that there's functionality that > is used that has no equivalent. > > [1] > https://solr.apache.org/guide/solr/latest/query-guide/result-grouping.html > [2] > https://solr.apache.org/guide/solr/latest/query-guide/collapse-and-expand-results.html > > ~ David Smiley > Apache Lucene/Solr Search Developer > http://www.linkedin.com/in/davidwsmiley --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@solr.apache.org For additional commands, e-mail: dev-h...@solr.apache.org
