How about creating another field for doing exact matches (a string); searching both and boosting the string match?
-Mike > -----Original Message----- > From: Imran [mailto:imranboho...@gmail.com] > Sent: Friday, October 29, 2010 6:25 AM > To: solr-user@lucene.apache.org > Subject: Influencing scores on values in multiValue fields > > Hi All > > We've got an index in which we have a multiValued field per document. > > Assume the multivalue field values in each document to be; > > Doc1: > bar lifters > > Doc2: > truck tires > back drops > bar lifters > > Doc 3: > iron bar lifters > > Doc 4: > brass bar lifters > iron bar lifters > tire something > truck something > oil gas > > Now when we search for 'bar lifters' the expectation (based on the > requirements) is that we get results in the order of Doc1, > Doc 2, Doc4 and Doc3. > Doc 1 - since there's an exact match (and only one) for the > search terms Doc 2 - since ther'e an exact match amongst the > values Doc 4 - since there's a partial match on the values > but the number of matches are more than Doc 3 Doc 3 - since > there's a partial match > > However, the results come out as Doc1, Doc3, Doc2, Doc4. > Looking at the explaination of the result it appears Doc 2 is > loosing to Doc3 and Doc 4 is loosing to Doc3 based on length > normalisation. > > We think we can see the reason for that - the field length in > doc2 is greater than doc3 and doc 4 is greater doc3. > However, is there any mechanism I can force doc2 to beat doc3 > and doc4 to beat doc3 with this structure. > > We did look at using omitNorms=true, but that messes up the > scores for all docs. The result comes out as Doc4, Doc1, > Doc2, Doc3 (where Doc1, Doc2 and > Doc3 gets the same score) > This is because the fieldNorm is not taken into account anymore (as > expected) and the termFrequence being the only contributing > factor. So trying to avoid length normalisation through > omitNorms is not helping. > > Is there anyway where we can influence an exact match of a > value in a multiValue field to add on to the overall score > whilst keeping the lenght normalisation? > > Hope that makes sense. > > Cheers > -- Imran >
