On 11/6/2013 6:28 AM, vicky desai wrote: > I am planning to use the docValues feature of Solr. I have added "docValues= > true" parameter to a few fields in my schema on which there is heavy > faceting and grouping query involved. While I noticed a considerable > improvement in faceting queries. I didnt get any improvements in grouping > query and instead places where i used "group.ngroups=true" in my query there > was around 3-4 times degradation in performance. > > Any know issues or possible workarounds for this case
The group.ngroups=true feature has bad performance. It's a fact that's well known. There is an issue to improve the situation, but mostly it's just a feature request with no patch and no significant ideas. https://issues.apache.org/jira/browse/SOLR-2963 There has been no activity on the issue since January, but the first comment lists what may be a workaround that improves performance when grouping on a single field. I personally have never used the grouping feature and don't know if the workaround is solid. This is all the information I could find. Thanks, Shawn
