Alex, With our lucene based implementation of Zulia ( https://github.com/zuliaio/zuliasearch) we have went back and forth. We started with Taxonomy and switched and then switched back to taxonomy. In our experience the Taxonomy based approach is more scalable and performant. We do large searches (sometimes returning millions of results) with about 20 facets being run with some high cardinality facets. A small dataset version of the tool that is backed by zulia we released for covid can be found here ( https://icite.od.nih.gov/covid19/search/#search:searchId=6089a5b7218c6902d422e907). If you click on the facet tab you can see how we use facets. I believe the use case might largely drive the choice.
Thanks, Matt On Wed, Apr 28, 2021 at 1:26 PM Alexander Lukyanchikov < alexanderlukyanchi...@gmail.com> wrote: > Hello everyone, > > We are trying to choose between Taxonomy and SortedSetDocValuesFacetField > implementations for faceted search, and based on available information and > our quick tests, the difference is the following - > > - Taxonomy is faster at query time (on our test workload, the difference > sometimes is higher than documented 25%). Also SortedSet adds latency to an > NRT refresh. > - Taxonomy is slower at index time, and unlike SortedSet implementation, it > does not scale as good with more than 4 threads (a lot of contention at > DirectoryTaxonomyWriter#addCategory() and UTF8TaxonomyWriterCache.get() > synchronized blocks) > - SortedSet does not support hierarchical queries > - SortedSet does not require a sidecar index > - Tie-break differences for labels with the same count > > Am I missing something, or that’s everything we should take into account as > of today? > > I know that Solr and ES use their own faceting for historical reasons, but > are there any other large Lucene-based products, which have chosen one > implementation over another? Do we know why? > Any insight on less known trade-offs and production experience is greatly > appreciated! > > -- > Thank you, > Alex >
