Re: Group by in Lucene ?

Hello,

yes I tried HitCollector but I am not satisfied with it because you can not use sorting with HitCollector unless you implement a way to use TopFieldTocCollector. I did not manage to do that in a performant way.

It is easier to first do a normal search und "group by" afterwards:

Iterate through the result documents and take one of each group. Each document has a groupingKey. I remember which groupingKey is already used and don't take another document of this group into the result list.

Regards,
Nina