https://issues.apache.org/jira/browse/SOLR-5894 had some pretty interesting looking work on heuristic counts for facets, among other things.
Unfortunately, it didn’t get picked up, but if you don’t mind using Solr 4.10, there’s a jar. On 11/4/16, 12:02 PM, "John Davis" <johndavis925...@gmail.com> wrote: Hi, I am trying to improve the performance of queries with facets. I understand that for queries with high facet cardinality and large number results the current facet computation algorithms can be slow as they are trying to loop across all docs and facet values. Does there exist an option to compute facets by just looking at the top-n results instead of all of them or a sample of results based on some query parameters? I couldn't find one and if it does not exist, has this come up before? This would definitely not be a precise facet count but using reasonable sampling algorithms we should be able to extrapolate well. Thank you in advance for any advice! John