This sounds like an ideal use case for payloads. You could attach a boost value to each term in your "keywords" field. See http://www.lucidimagination.com/blog/2009/08/05/getting-started-with-payloads/
Another common workaround is to create, say, 8 multi-valued fields with boosts 0.5, 1.0, 1.5, 2.0, 4.0, 8.0, 16.0, 32.0, 64.0 and index your keywords into the kw-field which has the nearest boost to what you want. For your example, that could be: kw05=, kw10=, kw15=politics;politicians, kw20=obama;barack, kw40=liberal, kw80= ..... -- Jan Høydahl - search architect Cominvent AS - www.cominvent.com On 10. feb. 2010, at 03.07, Yu-Shan Fung wrote: > Hi All, > > I'm trying to create an index of documents, where for each document, I am > trying to associate with it a set of related keywords, each with individual > boost values that I compute externally. > > eg: > Document Title: Democrats > related keywords: > liberal: 4.0 > politics: 1.5 > obama: 2.0 > etc. (hundreds of related keywords) > > Since boosts in solr is per field instead of per field-instance, I am trying > to get around this by creating dynamic fields for each related keyword, and > setting boost values accordingly. To be able to surface this document by > searching the related keywords, I have the schema setup to copy these > related keyword fields into the default text field. > > But when I query any of these related keywords, I get back fieldNorms with > the max value: > > 1.5409492E10 = (MATCH) weight(text:liberal in 11), product of: > 0.8608541 = queryWeight(text:liberal), product of: > 1.6840147 = idf(docFreq=109, maxDocs=218) > 0.51119155 = queryNorm > 1.79002368E10 = (MATCH) fieldWeight(text:liberal in 11), product of: > 1.4142135 = tf(termFreq(text:liberal)=2) > 1.6840147 = idf(docFreq=109, maxDocs=218) > > According to this email exchange between Koji and Mat Brown, > > http://www.mail-archive.com/solr-user@lucene.apache.org/msg23759.html > > The boost value from copyField's shouldn't be accumulated into the boost for > the text field, can anyone else verify this? This seem to go against what > I'm observing. When I turn off copyField, the fieldNorm goes back to normal > (in the single digit range). > > Any idea what could be causing this? I'm running Solr 1.4 in case that > matters. > > Any pointers/advice would be greatly appreciated! Thanks, > Yu-Shan
