Dear All, Background: We have a dataset containing hundreds of millions of records, we facet by dozens of fields with many of facet-excludes and have relatively small number of unique values in fields, around thousands. Before executing search, our users work with "advanced search" and goal is to populate dozens of filters with values which are applicable with other selected values, so basically this is a use case for facets with mincount=1, but without need in actual counts. Our performance tests showed that facet.method=enum works much better than fc\fcs, probably due to a specific ratio of "docset"\"unique terms count". For example average execution of query time with method fc=1500ms, fcs=2600ms and with enum=280ms. Profiling indicated the majority time for enum was spent on intersecting docsets.
So... We've implemented a patch that introduces an extension to facet calculation for method=enum. Basically it uses docSetA.intersects(docSetB) instead of docSetA. intersectionSize (docSetB). As a result we were able to reduce our average query time from 280ms to 60ms. How would you suggest to name such parameter? Now we call it "facet.enum.exists" but I'm not sure it's a good name. When we will clarify this little thing, I'll create a jira-issue and attach patch for review. Is there anybody willing to review and commit? Thank Alexey
