Hi, I was taking a look at the Solr searcher to see how the filterCache is used: https://github.com/apache/solr/blob/c2db3a943e665cfb39e9ea53640be40cf2c09fbc/solr/core/src/java/org/apache/solr/search/SolrIndexSearcher.java#L1379-L1398 Reading the code, it turned out that the filterCache is not used if the sort contains the score or if we don't have any score specified (by default, it sorts by score). As far as I know, the filterCache contains an unordered set of documents so the sort must be calculated after the application of the filter query. Then, also the score should be computed after the filter query to have a smaller set of documents. That being said, I don't understand why Solr does not use the filterCache if the score is somehow involved in the sort. In theory, it can
1. apply the filter query reducing the number of result 2. computes the score 3. sort the results Am I missing something? Happy new year, Daniele