I am not an expert in lucene scoring formula, but omintNorms=false makes the scoring formula a little bit more complex, taking into account boosting for fields and documents. If I'm not wrong (if I am please, correct me) I think that with omitNorms=false take into account the queryNorm(q) and norm(t,d) from formula: score(q,d) = coord(q,d) · queryNorm(q) · ∑ ( tf(t in d) · idf(t)2 · t.getBoost() · norm(t,d) ) so the formula will be more complex.
See http://lucene.apache.org/java/2_4_0/api/org/apache/lucene/search/Similarity.html, and http://old.nabble.com/scores-are-the-same-for-many-diferent-documents-td27623039.html#a27623039 multiValued option is used to create fields with multiple values. We use it one of our indexed modifying the schema.xml, adding a new field ... <field name="s_similar_name" type="text" indexed="true" stored="true" multiValued="true"/> ... This field is processed in a specific UpdateRequestProcessorFactory (write by us) from a comma separated field called 's_similar_names': ... public void processAdd(AddUpdateCommand cmd) throws IOException { SolrInputDocument doc = cmd.getSolrInputDocument(); String v = (String)doc.getFieldValue( "s_similar_names" ); if( v != null ) { String s_similar_names[] = v.split(","); for(String s_similar_name : s_similar_names){ if(!s_similar_name.equals("")) doc.addField( "s_similar_name", s_similar_name ); } } // pass it up the chain super.processAdd(cmd); } ... A processofactory is specified in solrconfig.xml ... # <updateRequestProcessorChain name="mychain"> # <processor class="org.apache.solr.update.processor.MyUpdateProcessorFactory"/> # <processor class="solr.LogUpdateProcessorFactory" /> # <processor class="solr.RunUpdateProcessorFactory" /> # </updateRequestProcessorChain> ... and adding this chain to XmlUpdateRequestHandler in solrconfig.xml: ... # <requestHandler name="/update" class="solr.XmlUpdateRequestHandler" > # <lst name="defaults"> # <str name="update.processor">mychain</str> # </lst> # </requestHandler> ... termVector is used to save more info about terns of a document in the index and save computational time in functions like MoreLikeThis. http://wiki.apache.org/solr/TermVectorComponent. We don't use it. adeelmahmood wrote: > > I was gonna ask a question about this but you seem like you might have the > answer for me .. wat exactly is the omitNorms field do (or is expected to > do) .. also if you could please help me understand what termVectors and > multiValued options do ?? > Thanks for ur help > > > Raimon Bosch wrote: >> >> >> Hi, >> >> We did some tests with omitNorms=false. We have seen that in the last >> result's page we have some scores set to 0.0. This scores setted to 0 are >> problematic to our sorters. >> >> It could be some kind of bug? >> >> Regrads, >> Raimon Bosch. >> > > -- View this message in context: http://old.nabble.com/some-scores-to-0-using-omitNorns%3Dfalse-tp27637436p27637827.html Sent from the Solr - User mailing list archive at Nabble.com.
