What about Function Queries? They can essentially take field values and use them as part of the score calculations....
Best Erick On Fri, Nov 4, 2011 at 6:28 AM, Martin Koch <m...@issuu.com> wrote: > Hi List > > I have a solr index where I want to include numerical fields in my ranking > function as well as keyword relevance. For example, each document has a > document view count, and I'd like to increase the relevancy of documents > that are read often, and penalize documents with a very low view count. I'm > aware that this could be achieved with a filter as well, but ignore that > for this question :) since this will be extended to other numerical fields. > > The keyword scoring works just fine and I can include the view count as a > factor in the scoring, but I would like to somehow express that the view > count accounts for e.g. 25% of the total score. This could be achieved by > mapping the view count into some predetermined fixed range and then > performing suitable arithmetic to scale to the score of the query. The > score of the term query is normalized to queryNorm, so I'd like somehow to > express that the view count score should be normalized to the queryNorm. > > If I look at the explain of how the score below is computed, the 17.4 is > the part of the score that comes from term relevancy. Searching for another > (set of) terms yields a different queryNorm, so I can't see how I can > a-priori pick a scaling function (I've used log for this example) and boost > factor that will give control of the final contribution of the view count > to the score. > > 19.14161 = (MATCH) sum of: > 17.403849 = (MATCH) max plus 0.1 times others of: > 16.747877 = (MATCH) weight(document:water^4.0 in 1076362), product of: > 0.22298127 = queryWeight(document:water^4.0), product of: > 4.0 = boost > 2.939238 = idf(docFreq=527730, maxDocs=3669552) > 0.018965907 = queryNorm > 75.108894 = (MATCH) fieldWeight(document:water in 1076362), product > of: > 25.553865 = tf(termFreq(document:water)=653) > 2.939238 = idf(docFreq=527730, maxDocs=3669552) > 1.0 = fieldNorm(field=document, doc=1076362) > [snip] > 1.7377597 = (MATCH) FunctionQuery(log(map(int(views),0.0,0.0,1.0))), > product of: > 1.8325089 = log(map(int(views)=68,min=0.0,max=0.0,target=1.0)) > 50.0 = boost > 0.018965907 = queryNorm > > Thanks in advance for your help, > /Martin >
