That's a good way. How does it perform?
Another way would be to store the "parent" topics in a field.
Whenever a parent node is drilled-into, simply search for all documents
with that parent. Perhaps not as elegant as your approach though.
I'd be interested in the performance comparison between the two approaches.
> I have a hierarchical taxonomy of documents that I would like users to be
> able to search either through search or "drill-down" faceting. The
> documents may appear at multiple points in the hierarchy. I've got a
> solution working as follows: a multivalued field labelled category which
> for
> each document defines where in the tree it should appear. For example:
> doc1
> has the category field set to "0/topics", "1/topics/computing",
> "2/topic/computing/systems".
>
> I then facet on the 'category' field, filter the results with fq={!raw
> f=category}1/topics/computing to get everything below that point on the
> tree, and use f.category.facet.prefix to restrict the facet fields to the
> current level.
>
> Full query something like:
>
> http://localhost:8080/solr/select/?q=something&facet=true&facet.field=category&fq={!rawf=category}1/topics/computing&f.category.facet.prefix=2/topic/computing
>
>
> Playing around with the results, it seems to work ok but despite reading
> lots about faceting I can't help feel there might be a better solution.
> Are
> there better ways to achieve this? Any comments/suggestions are welcome.
>
> (Any suggestions as to what interface I can put on top of this are also
> gratefully received!).
>
>
> Thanks,
>
> Russell
>
