[SOLR-2524] Adding grouping to Solr 3x

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.3
• Assignee: Martijn van Groningen
• Reporter: Martijn van Groningen
• Created: 17/May/11 23:41
• Updated: 06/Jan/12 10:23
• Resolved: 17/Jun/11 23:10

Description

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?

Issue Links

• is blocked by: LUCENE-3099 Grouping module should allow subclasses to set the group key per document
• is related to: SOLR-2665 Solr Post Group Faceting