O'Reilly logo

Apache Solr 3 Enterprise Search Server by Eric Pugh, David Smiley

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Result grouping/Field collapsing

Result Grouping and Field Collapsing are two names that suggest different ways of looking at the same Solr feature. Result grouping, the preferred name, is the ability to group the search results by a field value or some other criteria. This is very useful in using Solr for reporting but also for presenting top search results from multiple document categories. Field collapsing, the original name, is having the ability to collapse (that is remove / withhold) search result documents that have the same field value as a previous document. A common use-case is to mimic how Google only shows one result for a website. The feature is roughly similar to a SQL group by query; but the SQL incarnation returns aggregate summary ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required