Lucene’s default ranking function uses factors such as tf, idf, and norm to help calculate relevancy scores. Solr has now exposed these factors as function queries. docfreq(field,term) returns the number of documents that contain the term in the field. termfreq(field,term) returns the number of times the term appears in the […]

Solr relevancy function queries

I previously introduced Solr’s Result Grouping, also called Field Collapsing, that limits the number of documents shown for each “group”, normally defined as the unique values in a field or function query. Since then, there have been a number of bug fixes, performance improvements, and feature enhancements. You’ll need a […]

Solr Result Grouping / Field Collapsing Improvements