I'm using Solr for search.
I have documents that have an integer field "popularity".
I want to rank results by a combination of normal fulltext search relevance and popularity.
It's kinda like search in digg - result ranking is based on the search relevance as well as how many digs a posting has.
I don't have any specific ranking algorithm in mind. But is this something that can be done with solr?
Solr's FunctionQuery is exactly what you need: