Hi, I'm using the grouping feature of Solr to return a list of unique documents together with a count of the duplicates.
Essentially I use Solr's signature algorithm to create the "signature" field and use grouping on it. To provide good numbers for paging through my result list, I'd like to compute the total number of documents found (= matches) and the number of unique documents (= ngroups). Unfortunately, enabling "group.ngroups" considerably slows down the query (from 500ms to 23000ms for a result list of roughly 300000 documents). Is there a faster way to compute the number of groups (or unique values in the signature field) in the search result? My Solr instance currently contains about 50 million documents and around 10% of them are duplicates. Thank you, Michael
