Type: New Feature
Affects Version/s: None
Fix Version/s: 3.3
Grouping was recently added to Lucene 3x. See
LUCENE-1421 for more information.
I think it would be nice if we expose this functionality also to the Solr users that are bound to a 3.x version.
The grouping feature added to Lucene is currently a subset of the functionality that Solr 4.0-trunk offers. Mainly it doesn't support grouping by function / query.
The work involved getting the grouping contrib to work on Solr 3x is acceptable. I have it more or less running here. It supports the response format and request parameters (expect: group.query and group.func) described in the FieldCollapse page on the Solr wiki.
I think it would be great if this is included in the Solr 3.2 release. Many people are using grouping as patch now and this would help them a lot. Any thoughts?