Thank you Ahmet, looks like we could use this. Basically we would do periodic dumps of the (unique_id|computed_score) sorted by score and write it out to this file followed by a commit.
Found some more info here, for the benefit of others looking for something similar: http://dev.tailsweep.com/solr-external-scoring/ On Thu, 2011-05-05 at 13:12 -0700, Ahmet Arslan wrote: > > --- On Thu, 5/5/11, Sujit Pal <sujit....@comcast.net> wrote: > > > From: Sujit Pal <sujit....@comcast.net> > > Subject: Custom sorting based on external (database) data > > To: "solr-user" <solr-user@lucene.apache.org> > > Date: Thursday, May 5, 2011, 11:03 PM > > Hi, > > > > Sorry for the possible double post, I wrote this up but had > > the > > incorrect sender address, so I am guessing that my previous > > one is going > > to be rejected by the list moderation daemon. > > > > I am trying to figure out options for the following > > problem. I am on > > Solr 1.4.1 (Lucene 2.9.1). > > > > I have search results which are going to be ranked by the > > user (using a > > thumbs up/down) and would translate to a score between -1 > > and +1. > > > > This data is stored in a database table ( > > unique_id > > thumbs_up > > thumbs_down > > num_calls > > > > as the thumbs up/down component is clicked. > > > > We want to be able to sort the results by the following > > score = > > (thumbs_up - thumbs_down) / (num_calls). The unique_id > > field refers to > > the one referenced as <uniqueId> in the schema.xml. > > > > Based on the following conversation: > > http://www.mail-archive.com/solr-user@lucene.apache.org/msg06322.html > > > > > > ...my understanding is that I need to: > > > > 1) subclass FieldType to create my own RankFieldType. > > 2) In this class I override the getSortField() method to > > return my > > custom FieldSortComparatorSource object. > > 3) Build the custom FieldSortComparatorSource object which > > returns a > > custom FieldSortComparator object in newComparator(). > > 4) Configure the field type of class RankFieldType > > (rank_t), and a field > > (called rank) of field type rank_t in schema.xml of type > > RankFieldType. > > 5) use sort=rank+desc to do the sort. > > > > My question is: is there a simpler/more performant way? The > > number of > > database lookups seems like its going to be pretty high > > with this > > approach. And its hard to believe that my problem is new, > > so I am > > guessing this is either part of some Solr configuration I > > am missing, or > > there is some other (possibly simpler) approach I am > > overlooking. > > > > Pointers to documentation or code (or even keywords I could > > google) > > would be much appreciated. > > Looks like it can be done with > http://lucene.apache.org/solr/api/org/apache/solr/schema/ExternalFileField.html > > and > http://wiki.apache.org/solr/FunctionQuery > > You can dump your table into three text files. Issue a commit to load these > changes. > > Sort by function query is available in Solr3.1 though.
