Hi, https://issues.apache.org/jira/browse/SOLR-2553 - "Nested Field Collapsing" caught my attention.
I'm not familiar with the implementation details of grouping (aka field collapsing) or pivot faceting.... but shouldn't they share a lot of code and be treated as very closely related.... maybe even building on top of each other? I'm asking because I don't recall ever seeing anyone making this connection between grouping and pivot/hierarchical/nested faceting, YET: * grouping is a very popular feature * pivot faceting is popular * Elasticsearch guys invested a lot of time into the new aggregation framework which has aspects of both grouping and pivot faceting * (nested) grouping/pivot faceting are building blocks that make Solr more attractive for analytical workload and not just full-text search queries - see http://blog.sematext.com/2013/11/09/presentation-solr-for-analytics/ Or am I completely off in terms of grouping and pivot faceting being very closely related? Thanks, Otis -- Performance Monitoring * Log Analytics * Search Analytics Solr & Elasticsearch Support * http://sematext.com/