You could also use SynonymFilter? Why does the boost need to be encoded in the index (in a payload) vs at query time when you create the TermQuery for that term? Does the boost vary depending on the surrounding context / document?
Mike McCandless http://blog.mikemccandless.com On Wed, Mar 12, 2014 at 5:27 AM, Manuel Le Normand <manuel.lenorm...@gmail.com> wrote: > Hi, > I posted this question on the Solr mailing list but it has more to do with > Lucene. > > I have a performance and scoring problem for phrase queries > > 1. Performance - phrase queries involving frequent terms are very slow > due to the reading of large positions posting list. > 2. Scoring - I want to control the boost of phrase and entity (in > gazetteers) matches > > Indexing all terms as bi-grams and unigrams is not possible in my use case, > so I plan indexing only the useful bi-grams. Part of it will be achieved by > the CommonGram filter in which I put the frequent words. > > I think of going a step further and index phrase queries (extracted from my > query log) entities (from gazetteers). In order to control the boost on > these N-gram matches I plan adding payloads to these terms. > > I'm thinking of two different implementations: > > 1. Using MappingCharFilter - the mapping.txt would be > > #phrase-query > > term1 term2 term3 => term1_term2_term3|1 > > #entity > > firstName lastName => firstName_lastName|2 > > > Very simple to implement but an issue might be that I have 100k-1M > (depending on frequency) phrases/entities as above. I saw that > MappingCharFilter is implemented as an FST, so I'm not concerned with > memory footprint, but I'm concerned that iterating on the charBuffer for > long documents might cause problems. > > 2. Using the shingleTokenFilter - customizing it to compare the output > against my gazetteers. It would demand and FST implementation in this > TokenFilter. > > > Will I get a quick win with opt.1? How hard would be implementing opt.2? > > General question: Is the above N-gram + payload resolution a common > practice? > > Thanks in advance, > Manuel --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
