For an application that already has a Lucene Index, I would like to implement a facet search that return result aggregations in two dimensions. From the Lucene examples [1] I can see how to do a simple facet search that collects facets in one dimension but I haven't seen any examples for a two-step faceting.
Let's say I have a query X and two facet dimensions A and B on which I would like to aggregate the hits. - How can I achieve the following result (I am only interested in count of distinct pairs A|B): X + A1 - B1 (12) | B2 (3) | B4 (8) | + A2 - B1 (1) | - B5 (8) | - B9 (1) | - B14 (15) | - B15 (42) | - B20 (95) | + A3 - B2 (3) | - B3 (1) | - B4 (3) | - B27 (7) | - B31 (10) | - B32 (21) . . . | + An - B4 (75) - B9 (6) - B15 (18) - B41 (11) For a naive solution I could perform a facet search on dim A, iterate over A1..An and then, for each facet of A, perform another facet search on dim B. But that is probably not efficient. What is the recommended way to do this? I can see that Solr/ES provide such a feature (sub-facet/nested aggregation) via their query language but I would prefer to stick with a pure Lucene solution for now. -Matthias [1] https://lucene.apache.org/core/7_7_2/demo/org/apache/lucene/demo/facet/package-summary.html --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org