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Hemant Verma edited comment on SOLR-4381 at 6/5/13 8:42 AM: ------------------------------------------------------------ While using this patch I found one scenario in which it is not working properly. I have in my synonyms list the below keywords: pepsi,pepsico,pbg outsourcing,rpo,offshoring Difference in expanding synonyms comes up when I use any of the word with stopword as a prefix. Search Keyword ------------ Expanded Result ---------------------------------------------------------------- pepsi -----------------------> pepsi, pepsico, pbg pbg -------------------------> pepsi, pepsico, pbg the pepsi -----------------> pepsi, pepsico the pbg --------------------> pepsi, pbg outsourcing -----------------> outsourc, offshor, rpo the outsourcing -------------> outsourc, offshor The above expanded synonyms result shows that when we use any keyword (available in synonym list) prefixed with stopword then expanded synonyms do miss few synonym. was (Author: hemantverma09): While using this patch I found one scenario in which it is not working properly. I have in my synonyms list the below keywords: pepsi,pepsico,pbg outsourcing,rpo,offshoring Difference in expanding synonyms comes up when I use any of the word with stopword as a prefix. Search Keyword Expanded Result -------------- --------------- pepsi pepsi, pepsico, pbg pbg pepsi, pepsico, pbg the pepsi pepsi, pepsico the pbg pepsi, pbg outsourcing outsourc, offshor, rpo the outsourcing outsourc, offshor The above expanded synonyms result shows that when we use any keyword (available in synonym list) prefixed with stopword then expanded synonyms do miss few synonym. > Query-time multi-word synonym expansion > --------------------------------------- > > Key: SOLR-4381 > URL: https://issues.apache.org/jira/browse/SOLR-4381 > Project: Solr > Issue Type: Improvement > Components: query parsers > Reporter: Nolan Lawson > Priority: Minor > Labels: multi-word, queryparser, synonyms > Fix For: 4.4 > > Attachments: SOLR-4381-2.patch, SOLR-4381.patch > > > This is an issue that seems to come up perennially. > The [Solr > docs|http://wiki.apache.org/solr/AnalyzersTokenizersTokenFilters#solr.SynonymFilterFactory] > caution that index-time synonym expansion should be preferred to query-time > synonym expansion, due to the way multi-word synonyms are treated and how IDF > values can be boosted artificially. But query-time expansion should have huge > benefits, given that changes to the synonyms don't require re-indexing, the > index size stays the same, and the IDF values for the documents don't get > permanently altered. > The proposed solution is to move the synonym expansion logic from the > analysis chain (either query- or index-type) and into a new QueryParser. See > the attached patch for an implementation. > The core Lucene functionality is untouched. Instead, the EDismaxQParser is > extended, and synonym expansion is done on-the-fly. Queries are parsed into > a lattice (i.e. all possible synonym combinations), while individual > components of the query are still handled by the EDismaxQParser itself. > It's not an ideal solution by any stretch. But it's nice and self-contained, > so it invites experimentation and improvement. And I think it fits in well > with the merry band of misfit query parsers, like {{func}} and {{frange}}. > More details about this solution can be found in [this blog > post|http://nolanlawson.com/2012/10/31/better-synonym-handling-in-solr/] and > [the Github page for the > code|https://github.com/healthonnet/hon-lucene-synonyms]. > At the risk of tooting my own horn, I also think this patch sufficiently > fixes SOLR-3390 (highlighting problems with multi-word synonyms) and > LUCENE-4499 (better support for multi-word synonyms). -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org