On Fri, Jun 19, 2015, at 06:20 AM, Derek Poh wrote: > Hi > > I read about "collapsingQParser returns the facet count the same as > group.truncate=true" and has this issue with the facet count and the > after filter facet count notthe same. > Using group.facetdoes not has this issue but it's performance is very > badcompared to collapsingQParser. > > I trying to understand why collapsingQParser behave this way and will > need to explain to management. > > Can someone explain how collapsingQParser calculatethefacet > countscompated to group.facet?
I'm not familiar with group.facet. But to compare traditional grouping to the collapsingQParser - in traditional grouping, all matching documents remain in the result set, but they are grouped for output purposes. However, the collapsingQParser is actually a query filter. It will reduce the number of matching results. Any faceting that happens will happen on the filtered results. I wonder if you can use this syntax to achieve faceting alongside collapsing: q=whatever fq={!collapse tag=collapse}blah facet.field={!ex=collapse}my_facet_field This way, you get the benefits of the CollapsingQParserPlugin, with full faceting on the uncollapsed resultset. I've no idea how this would perform, but I'd expect it to be better than the grouping option. Upayavira