nested filter within a facet_filter fails to return nested facet terms

[btiernay]

The general query form that exhibits this behavior is:

{
   "size":0,
   "facets":{
      "nested1":{
         "terms":{
            "field":"x"
         },
         "nested":"nested1",
         "facet_filter":{
            "nested":{
               "path":"nested1",
               "query":{
                  "match_all":{}
               }
            }
         }
      }
   }
}

Please see the curl recreation example here:

https://gist.github.com/btiernay/6378567

[junjun-zhang]

With "join": false option, facet will produce desired result. When join is disabled, facet will apply to the nested documents instead of the joined root document. See #2606 for more details.

{
   "size":0,
   "facets":{
      "nested1":{
         "terms":{
            "field":"x"
         },
         "nested":"nested1",
         "facet_filter":{
            "nested":{
               "path":"nested1",
               "join":false,
               "query":{
                  "match_all":{}
               }
            }
         }
      }
   }
}

[btiernay]

@junjun-zhang Ah, very nice. Didn't know that option existed as it is undocumented. Thanks :)

[junjun-zhang]

Yes, this should be documented, and maybe "join":false should be the default when join option is omitted. I assume more users expect nested facets work on nested docs instead of joined root docs.