A custom query could improve on the situation by not pulling multiple docs/positions enum for a single term. E.g. the patch on https://issues.apache.org/jira/browse/LUCENE-5288 (which never got committed: too controversial) has such a query, letting you customize how positions are scored for boolean term query matches. Maybe you could start from it and see how performance compares vs the SpanFirstQuery approach...
Mike McCandless http://blog.mikemccandless.com On Mon, Jan 26, 2015 at 6:14 AM, Uwe Schindler <u...@thetaphi.de> wrote: > Hi, > > it depends on the query structure. In fact, SpanFirstQuery is slow (all span > queries are slow because of position use, this may improve in the future). > > You question was about using multiple fields - in fact querying for the same > terms on multiple fields and/or different query types: This is the standard > approach to tune the relevance! But it always has a cost. In most cases you > will not see a large difference (unless you use phrase or span queries). A > very good explanation what can be done using this is described in the > Elasticsearch Guide: > http://www.elasticsearch.org/guide/en/elasticsearch/guide/current/multi-field-search.html > > Uwe > > ----- > Uwe Schindler > H.-H.-Meier-Allee 63, D-28213 Bremen > http://www.thetaphi.de > eMail: u...@thetaphi.de > > >> -----Original Message----- >> From: Alexey Morozov [mailto:moro...@gmail.com] >> Sent: Monday, January 26, 2015 11:49 AM >> To: java-user@lucene.apache.org >> Subject: Re: Absolute term position in scoring >> >> Hello! >> >> I'd like to ask if this approach: construct a complex query consisting of a >> boosted "specialized" part and an "ordinary" part with no boost, - doesn't >> [necessarily] cause a significant performance degradation compared to a >> "custom query", specialized for a particular need. >> >> Thanks in advance, >> Alexey Morozov >> >> 26.01.2015 14:57, Michael McCandless пишет: >> > Well you could have ordinary term queries, and then a SHOULD >> > SpanFirstQuery clause with a boost, to give higher scores to those >> > docs that also had the >> > term(s) close to the start of the document. >> > >> > >> > Mike McCandless >> > >> > http://blog.mikemccandless.com >> > >> > On Sun, Jan 25, 2015 at 5:44 PM, Luis A Lastras <lastr...@us.ibm.com> >> wrote: >> > >> >> Thanks I didn't know about SpanFirstQuery. I can likely get something >> >> going with that. I was still hoping that we could affect the scoring >> >> formula with the position itself, but maybe this is not feasible. >> >> >> >> Luis >> >> >> >> >> >> >> >> ------------------------------ >> >> >> >> >> >> >> >> *Luis A Lastras, Ph.D. Research Staff Member & Manager, Concept >> Analytics, >> >> IBM Watson* >> >> *Member of the iBM Academy of Technology* >> >> >> >> *IBM Master Inventor email: **lastr...@us.ibm.com* >> >> <em...@region.ibm.com> >> >> * | Tel: 914-945-3613 <914-945-3613> | Cell: 914-382-1879 <914-382-1879> >> >> address: 1101 Kitchawan Rd, Office 28-132, Yorktown Heights, NY, >> >> 10598* >> >> >> >> >> >> >> >> >> >> <http://www.facebook.com/ibmwatson> >> >> >> >> >> >> ------------------------------ >> >> >> >> >> >> >> >> [image: Inactive hide details for Michael McCandless ---01/25/2015 >> >> 08:12:18 AM---Maybe SpanFirstQuery? Mike McCandless]Michael >> >> McCandless >> >> ---01/25/2015 08:12:18 AM---Maybe SpanFirstQuery? Mike McCandless >> >> >> >> From: Michael McCandless <luc...@mikemccandless.com> >> >> To: Lucene Users <java-user@lucene.apache.org> >> >> Date: 01/25/2015 08:12 AM >> >> Subject: Re: Absolute term position in scoring >> >> ------------------------------ >> >> >> >> >> >> >> >> Maybe SpanFirstQuery? >> >> >> >> >> >> Mike McCandless >> >> >> >> http://blog.mikemccandless.com >> >> >> >> On Sat, Jan 24, 2015 at 9:34 PM, Luis A Lastras <lastr...@us.ibm.com> >> >> wrote: >> >> >> >>> Is it possible to incorporate in Lucene's scoring function the >> >>> position >> >> of >> >>> a matching term (say as measured from the top of the document). The >> >>> scenario is, if the set of documents tend to lk about the most >> >>> important stuff at the beginning of the document, then we would like >> >>> to give preference to documents that mention a term close to the top. >> >>> >> >>> Thanks, >> >>> >> >>> Luis >> >>> >> >>> >> >>> >> >>> ------------------------------ >> >>> >> >>> >> >>> >> >>> *Luis A Lastras, Ph.D. Research Staff Member & Manager, Concept >> >> Analytics, >> >>> IBM Watson* >> >>> *Member of the iBM Academy of Technology* >> >>> >> >>> *IBM Master Inventor email: **lastr...@us.ibm.com* >> >>> <em...@region.ibm.com >> >>> >> >>> * | Tel: 914-945-3613 <914-945-3613> | Cell: 914-382-1879 <914-382- >> 1879> >> >>> address: 1101 Kitchawan Rd, Office 28-132, Yorktown Heights, NY, >> >> 10598* >> >>> >> >>> >> >>> >> >>> <http://www.facebook.com/ibmwatson> >> >>> >> >>> >> >>> ------------------------------ >> >>> >> >>> >> >>> >> >> >> >> >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org >> For additional commands, e-mail: java-user-h...@lucene.apache.org > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org > For additional commands, e-mail: java-user-h...@lucene.apache.org > --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscr...@lucene.apache.org For additional commands, e-mail: java-user-h...@lucene.apache.org
