Solr multifield query sorting incorrectly - search

Question

I am trying to customize a multifield score on solr.
< field name="cat" type="string" indexed="true" stored="true" required="true" multiValued="false" />
< field name="name" type="text_en_splitting" indexed="true" stored="true" required="true" />
< field name="tags" type="text_general" indexed="true" stored="true" required="true" multiValued="true" />
< field name="popularity" type="sint" indexed="true" stored="true" required="true" />
< field name="id" type="string" indexed="true" stored="true" required="true" multiValued="false" />
where sint is a sortable int
I want to rank by
query match with 'name'
'popularity'
query match with 'tags'.
Here is my solrj code:
HttpSolrServer solr = new HttpSolrServer("http://localhost:8983/solr");
SolrQuery query = new SolrQuery();
query.setQuery("National");
query.setFields("cat name tags popularity id score");
query.setStart(0);
//boost
query.set("defType", "edismax");
query.set("qf", "name^999.0 tags^2.0 popularity^-1000.0");
QueryResponse response = solr.query(query);
SolrDocumentList results = response.getResults();
for (int i = 0; i < results.size(); ++i) {
System.out.println(results.get(i));
}
When I test, all my docs give the same score even though they have different tags and popularity. I do not want to do copyfield types and setAddField only sorts based on one field...
This seems like a very common issue but I scored the whole web and haven't found a solution to my problem. Thanks in advance for the responses! :)

Answer 1

First, to understand how dismax score is computed, see:
http://searchhub.org/2010/05/23/whats-a-dismax/
where it says: score is determined by the maximum score of it’s subclauses — instead of the sum like a BooleanQuery. The individual scores are not added, but most likely dominated by the name match, which is why you are seeing the same score for all results.
Also I am not sure what your intent with popularity^-1000.0 is. I guess you want to boost the results by popularity.
You can use the standard query parser and try something like this:
q={!boost popularity}name:National^999.0 OR tags:National^2.0