Group By in Lucene

Question

Does Lucene support group by aggregations? Let's say I have an index with multiple employees with the fields name, job and salary. I want to get for each job the highest salary. Is there any way to get this information by using Lucene? In SQL I would get this information by SELECT job, MAX(salary) FROM employees GROUP BY job .

I'm using Lucene 7.4.0, the latest version and I know that typically people use Elasticsearch or Solr. However in my use case I have only an embedded Lucene.

Answer 1

you can you different collectors for this. See Grouping Javadoc documentation for more informations. I've never used it but it seems to be pretty powerful.