(repost with a fresh email)
I read that a simple way to implement hierarchical facet is to
concatenate strings with a separator. Something like
"level1>level2>level3" with ">" as the separator.
A problem with this approach is that the number of facet values will greatly
increase.
For
example I have a facet "Location" with the hierarchy
country>state>city. Using the above approach every single city
will lead to a separate facet value. With tens of thousands of cities
in the world the response from Solr will be huge. And then on the
client side I'd have to loop through all the facet values and combine
those with the same country into a single value.
Ideally Solr
would be "aware" of the hierarchy structure and send back responses
accordingly. So at level 1 Solr will send back facet values based on
country (100 or so values). Level 2 the facet values will be based on
the states within the selected country (a few dozen values). Next level
will be cities within that state. and so on.
Is it possible to implement hierarchical facet this way using Solr?
