I have a pair of multi-valued index fields, author and author_norm, and I've created a hierarchical facet field for them using the pattern described at https://wiki.apache.org/solr/HierarchicalFaceting#Indexed_Terms. The facet values look like this:
0/Blow, J
1/Blow, J/Blow, Joe
1/Blow, J/Blow, Joseph
1/Blow, J/Blow, Jennifer
0/Smith, M
1/Smith, M/Smith, Michelle
1/Smith, M/Smith, Michael
1/Smith, M/Smith, Mike
Authors are associated to article records, and in most cases an article will have many authors. This means that for a Solr query that returns 100+ articles, there will potentially be 1000+ authors represented.
My problem is that when I go to display this hierarchy to the user, due to my facet.limit and facet.mincount being set to sane values, I do not have the complete set of 2nd-level values, i.e., the 2nd level of my hierarchy will be cut-off at a certain point. I will have something like this:
- Blow, J (30)
- Blow, Joe (17)
- Blow, Joseph (9)
- Smith, M (22)
- Smith, Michelle (14)
- Smith, Michael (6)
I would like to also have the "Blow, Jennifer (4)" and "Smith, Mike (2)" entries in this list, but they're not returned in the response because mincount cutoff is 5. So I end up with a confusing display (17 + 9 != 30, etc).
One option would be to put a little "(more)" link at the bottom of every 2nd-level list and fetch the full set via ajax. I'm not crazy about this solution because it's asking users to work/click more than they really should have to, and also because I can't control the length of the initial 2nd-level listing; sometimes it'll be 3 names + "(more)", sometimes 2 or even 1. That's just ugly.
I could set mincount=1 and limit=-1 for just my hierarchical facet field, but that would be nuts because for a large query (100k hits) I would be fetching 100k+ values I don't need. I only need the full set of 2nd-level values for the top N 1st-level values.
So unless someone has a better suggestion, I'm assuming I need to do some kind of follow-up query. So after all that, here's what I'm really asking: is is there a way to fetch these 2nd-level values in a single follow-up query. Given an initial solr response, how can I get all the 2nd-level permutations of just the top N 1st-level values of my hierarchy?
Thanks!
PS, I'm using Solr 4.0.
